Politics, Economics and other Stuff

Black Vulture Sighting

My wife claims a black vulture sighting in our new neighborhood.  I've not seen it yet. 

Smart Animal Stories

From The Guardian via MR:

At the Institute for Marine Mammal Studies in Mississippi, Kelly the dolphin has built up quite a reputation. All the dolphins at the institute are trained to hold onto any litter that falls into their pools until they see a trainer, when they can trade the litter for fish. In this way, the dolphins help to keep their pools clean.

Kelly has taken this task one step further. When people drop paper into the water she hides it under a rock at the bottom of the pool. The next time a trainer passes, she goes down to the rock and tears off a piece of paper to give to the trainer. After a fish reward, she goes back down, tears off another piece of paper, gets another fish, and so on. This behaviour is interesting because it shows that Kelly has a sense of the future and delays gratification. She has realised that a big piece of paper gets the same reward as a small piece and so delivers only small pieces to keep the extra food coming. ...

Her cunning has not stopped there. One day, when a gull flew into her pool, she grabbed it, waited for the trainers and then gave it to them. It was a large bird and so the trainers gave her lots of fish. This seemed to give Kelly a new idea. The next time she was fed, instead of eating the last fish, she took it to the bottom of the pool and hid it under the rock where she had been hiding the paper. When no trainers were present, she brought the fish to the surface and used it to lure the gulls, which she would catch to get even more fish. After mastering this lucrative strategy, she taught her calf, who taught other calves, and so gull-baiting has become a hot game among the dolphins.

Saturn Ring Photography

via the Boston Globe:

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The moon Prometheus and its nearby disturbance of Saturn's F ring. Prometheus periodically gores the F ring, drawing out streamers of material from the ring. The image was taken in visible light at a distance of approximately 950,000 km (590,000 mi) from Saturn. (NASA/JPL/Space Science Institute) 

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Jagged looking shadows stretch away from vertical structures of ring material created by the moon Daphnis, a bright dot (8 km, or 5 mi across) casting a thin shadow just to the left of the center of the image. The moon has an inclined orbit, and its gravitational pull perturbs the orbits of the particles of the A ring forming the Keeler Gap's edge and sculpting the edge into waves having both horizontal (radial) and out-of-plane components. These scenes are possible only during the few months before and after Saturn's equinox, which occurs only once in about 15 Earth years. This image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 26, 2009, at a distance of approximately 823,000 km (511,000 mi) from Daphnis. (NASA/JPL/Space Science Institute)

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Another view of waves in the edges of the Keeler gap in Saturn's A ring, created by the embedded moon Daphnis. Image acquired on July 11, 2009, at a distance of approximately 496,000 km (308,000 mi) from Daphnis. (NASA/JPL/Space Science Institute)

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Cassini captured this image of a small object in the outer portion of Saturn's B ring casting a shadow on the rings as Saturn approaches its August 2009 equinox, on July 26, 2009. This new moonlet, situated about 480 km (300 mi) inward from the outer edge of the B ring, was found by detection of its shadow which stretches 41 km (25 mi) across the rings. The shadow length implies the moonlet is protruding about 200 meters, or 660 feet, above the ring plane. If the moonlet is orbiting in the same plane as the ring material surrounding it, which is likely, it must be about 400 meters, or 1,300 feet, across. (NASA/JPL/Space Science Institute)

Nesting albatross die from a diet of plastic

via Climate Shifts, photographs of dead albatross chicks in one of the most remote parts of the world. 

These photographs of albatross chicks were made just a few weeks ago on Midway Atoll, a tiny stretch of sand and coral near the middle of the North Pacific. The nesting babies are fed bellies-full of plastic by their parents, who soar out over the vast polluted ocean collecting what looks to them like food to bring back to their young. On this diet of human trash, every year tens of thousands of albatross chicks die on Midway from starvation, toxicity, and choking.

To document this phenomenon as faithfully as possible, not a single piece of plastic in any of these photographs was moved, placed, manipulated, arranged, or altered in any way. These images depict the actual stomach contents of baby birds in one of the world's most remote marine sanctuaries.

Reintroducing Cheetahs in India

The BBC reports.  I had no idea there even were cheetahs in Indian in historical times.  I'd heard of the Indian lion, but lions have been in many places in historical times. 

What I don't understand is how cheetahs in India lines up the well known low diversity of cheetahs, attributed to a recent population bottleneck, presumably in Africa.  Did cheetahs radiate out of Africa since then?  Thinking about it, it probably does make some sense, with ice age driven climate change -- with its massive impact on tropical vegetation cover -- pushing environmental change.  Still, what drove cheetahs so close to extinction in the recent past?  Wouldn't ice age climate conditions -- with savannah replacing forest -- favor the cheetah at least in some areas?   

Wiki writes:

The Asiatic Cheetah once ranged from Arabia to India, through Iran, central Asia, Afghanistan, and Pakistan. In Iran and the Indian subcontinent, it was particularly numerous. Cheetahs are the only big cat that can be tamed and trained to hunt gazelle. The Mughal Emperor of India, Akbar, was said to have had 1,000 cheetahs at one time, something depicted in many Persian and Indian miniature paintings. The numerous constraints regarding the Cheetah’s conservation contribute to its general susceptibility and its very complex conservation: e.g., its low fertility rate, the high mortality rate of the cubs due to genetic factors, and the fact that females are the ones who select mates, have been reasons why captive breeding has had such a poor record. A Cheetah-specific issue is its gene pool. Scientists are aware of the fact that all the Cheetahs in the world have a very similar immune system which means that they all have the same vulnerability to the same diseases; this is due to an interbreeding – approximately 12,000 years ago – that influenced the Cheetah’s gene pool dramatically. The Cheetah will not be a “robust, vigorous species anytime in the foreseeable future"^[10]

By the beginning of the twentieth century, the species was already heading for extinction in many areas. The last physical evidence of the Asiatic Cheetah in India was three shot by the Maharajah of Surguja in 1947 in eastern Madhya Pradesh. By 1990, the Asiatic Cheetah appeared to survive only in Iran. Estimated to number more than 200 during the 1970s, more recently Iranian biologist Hormoz Asadi estimated that the number of Asiatic Cheetahs left to be between 50 and 100 and figures for 2005-2006 are between 50 and 60 in the wild. Most of these 60 Asiatic Cheetahs live in Iran on the Kavir desert. A remnant population inhabits the dry terrain covering the border of Iran and Pakistan. In the areas in which the cheetah lives, locals say they have not seen it for more than fifteen years.

The (re)introduced cheetahs would be from Africa.  Probably good enough.  A reminder that Africa serves as a refuge for large animals driven to extinction recently in Europe and Asia. 

"Hunting of Blackbuck with Cheetah" Drawn by James Forbes in South Gujarat. Oriental Memoirs, Vol. I, 1812.

Butterfly

What species?  Looks like a red spotted purple to me, a mimic of the poisonous pipevine swallowtail. 

Also, a bonus toad photo.  Looks like an American toad, a very common species we also have in the yard in CT.  Quite small, I'd say less than an inch maybe half an inch, magnification here is similar as for the butterfly above:

Wild Fires

via Drum, Tom Kenworthy writes:

In the United States to date about 5.2 million acres — an area larger than Massachusetts  —have burned this year.

Monarch Butterfly

Got one accidental photo of the Monarch in flight, but at 1/500s there's too much blur. Also not a macro lens but the 17-55mm. Finally, this is shot at f/8 and I have the impression the lens performs better wider open, at f/5.6 or so. Below the lens wide open at f/2.8. 

Animals mix the ocean

This recent article in Nature gave me on of those occaional 'am I dreaming?' sensations.  The notion that animals may contribute a similar amount to ocean mixing as winds and tides was novel, almost shocking, for me. 

Kakani Katija & John O. Dabiri, A viscosity-enhanced mechanism for biogenic ocean mixing

Recent observations of biologically generated turbulence in the ocean have led to conflicting conclusions regarding the significance of the contribution of animal swimming to ocean mixing. Measurements indicate elevated turbulent dissipation—comparable with levels caused by winds and tides—in the vicinity of large populations of planktonic animals swimming together¹. However, it has also been noted that elevated turbulent dissipation is by itself insufficient proof of substantial biogenic mixing, because much of the turbulent kinetic energy of small animals is injected below the Ozmidov buoyancy length scale, where it is primarily dissipated as heat by the fluid viscosity before it can affect ocean mixing². Ongoing debate regarding biogenic mixing has focused on comparisons between animal wake turbulence and ocean turbulence^{3, 4}. Here, we show that a second, previously neglected mechanism of fluid mixing—first described over 50 years ago by Charles Darwin⁵— is the dominant mechanism of mixing by swimming animals. The efficiency of mixing by Darwin's mechanism is dependent on animal shape rather than fluid length scale and, unlike turbulent wake mixing, is enhanced by fluid viscosity. Therefore, it provides a means of biogenic mixing that can be equally effective in small zooplankton and large mammals. A theoretical model for the relative contributions of Darwinian mixing and turbulent wake mixing is created and validated by in situ field measurements of swimming jellyfish using a newly developed scuba-based laser velocimetry device⁶. Extrapolation of these results to other animals is straightforward given knowledge of the animal shape and orientation during vertical migration. On the basis of calculations of a broad range of aquatic animal species, we conclude that biogenic mixing via Darwin's mechanism can be a significant contributor to ocean mixing and nutrient transport.

I got the same 'am I dreaming' feeling with another Nature paper: Ju Young Lee, Byung Hee Hong, Woo Youn Kim, Seung Kyu Min, Yukyung Kim, Mikhail V. Jouravlev, Ranojoy Bose, Keun Soo Kim, In-Chul Hwang, Laura J. Kaufman, Chee Wei Wong, Philip Kim & Kwang S. Kim, Near-field focusing and magnification through self-assembled nanoscale spherical lenses:

It is well known that a lens-based far-field optical microscope cannot resolve two objects beyond Abbe's diffraction limit. Recently, it has been demonstrated that this limit can be overcome by lensing effects driven by surface-plasmon excitation^{1, 2, 3}, and by fluorescence microscopy driven by molecular excitation⁴. However, the resolution obtained using geometrical lens-based optics without such excitation schemes remains limited by Abbe's law even when using the immersion technique⁵, which enhances the resolution by increasing the refractive indices of immersion liquids. As for submicrometre-scale or nanoscale objects, standard geometrical optics fails for visible light because the interactions of such objects with light waves are described inevitably by near-field optics⁶. Here we report near-field high resolution by nanoscale spherical lenses that are self-assembled by bottom-up integration⁷ of organic molecules. These nanolenses, in contrast to geometrical optics lenses, exhibit curvilinear trajectories of light, resulting in remarkably short near-field focal lengths. This in turn results in near-field magnification that is able to resolve features beyond the diffraction limit. Such spherical nanolenses provide new pathways for lens-based near-field focusing and high-resolution optical imaging at very low intensities, which are useful for bio-imaging, near-field lithography, optical memory storage, light harvesting, spectral signal enhancing, and optical nano-sensing.

I have no idea how this works. 

Krakatoa is still active

via Climatechange, from the Daily Mail.

Owl again

That owl again.  I'm more aggressive here about getting into the shadows, probably too much so. 

Below processed like a photo without any contrast issues -- does provide a better sense of the light:

Tiger Extinction

Things going about as expected:

Panna National Park, in the central state of Madhya Pradesh, had 24 tigers three years ago, but now officially joins the Sariska reserve in Rajasthan on zero. Panna's tiger demise is particularly embarrassing because "warning bells were sounded regularly for the last eight years," according to a report prepared by the central forest ministry (BBC).

Big cats are reportedly also in decline in the smaller Sanjay National Park, also in Madhya Pradesh, where tigers have not been seen for a year.

A century ago, 40,000 tigers roamed India. Now there are only 1,400 left (according to a February 2008 government census).

My understanding is that the problem is humans in the tiger reserves, no matter what people say about the possibility of coexistence or other causes. 

Which Mimosa is this?

This was going to be a post on the question of why this mimosa tree has such a strange color, but I don't know if the color comes through in these photos with the late afternoon lighting and I cannot determine which of the ~400 mimosa species this is. I assume the color has something to do with the metabolism of the tree, a metabolism presumably well adapted to the temperature, moisture, soil, sun exposure and foragers of the tree in its typical environment.  There is a whole theory of leaf size and appearance based on metabolic function, but I couldn't outline who the theory works. 

Besides color, leaf size is also not standard for trees in the Northeast.

Random Nature Photos

From the lens and camera that I dropped today. The seagull is a bit off focus, but I don't think that is a camera problem, just a faraway -- this is a crop of the original photo -- seagull moving fast. The usual caveat that the monitor I'm using while on vacation isn't the best and makes detail, especially color and contrast, hard to see...

Backyard owl

A great horned owl high up on a tree in the backyard today.  See also the backyard owl at our house back in 2007.  

Chicken are here

One of the great aunts procured two chicken and two baby goats.  All showed up yesterday. Here's one of the chicken.  Shots of the goats all have kids in them.  Hard for me to tell if the photo is properly processed since I'm using an old and very dull laptop monitor. 

Update #1: as David asks in comments, what's the deal with the clipped beak? I assume this is because these are rental chicken that are rented to families with kids.  I am not involved in the process, but I'll ask. No idea how annoying this is to the chicken. 

Update #2: on a bit more reflection, it seems to me that clipping beaks may just be what one does if one holds chicken in close quarters (i.e. where these chicken come from).  Though this may be a bit more of a clip than most, I don't know. 

Update #3: David writes:

Clipping beaks impairs their ability to forage. I think they just do that for factory farms. Hens are usually pretty gentle. Roosters are different, of course.
Looks like a Rhode Island Red. Is it laying eggs for you?

One large egg on Monday, no reports of any more that have made it to me. 

Local Geese

Shot from the moving car down by the pond at the end of our street. 

'The ecological disaster that is dolphin safe tuna'

via 3QD, 'The ecological disaster that is dolphin safe tuna'. 

Woodpecker in our Garage

This woodpecker has been trying to get out of our garage for hours now, but she only tries this one window, which is too high for us to open. 

Update #1: the woodpecker finally escaped sometime this morning, after around 20 hours of being unable to get out of the garage.  Or she is simply dead someplace where we can't see her. 

In other news, we did find a dead hummingbird on our front path this morning. 


Update #2: a bit hard to get a decent focus in the dark, but I didn't want to shoot too many takes with flash and stress the bird further. 

Jellyfish replacing fish as top predators in parts of the ocean?

Anthony J. Richardson, Andrew Baku, Graeme C. Hays and Mark J. Gibbons, The jellyfish joyride: causes, consequences and management responses to a more gelatinous future is a nice thought piece on possible jellyfish threat (via. Climate Shifts).  I cannot judge its quality, but Trends in Ecology and Evolution is a respected journal. The big story is possible strong positive feedbacks by which jellyfish overcome control on their population by fish in stressful environments by suppressing fish populations. 

The most prominent regional jellyfish outbreaks of recent decades have followed collapses of formerly dominant local stocks of small filter-feeding pelagic fishes....Major jellyfish outbreaks have followed overexploitation and collapse of a locally dominant, small filter-feeding fish stock (e.g. anchovy, sardine or herring) in situations where another rapidly responding, similar fish species is not available as an adequate replacement. For example, in the northern Benguela upwelling system, where intense fishing decimated sardine stocks and jellyfish now dominate [11], maximum anchovy abundance has historically been limited to ~10% of maximum sardine biomass [64] (possibly because the weakly swimming anchovy might be incapable of coping as well as the larger sardine in this highly energetic upwelling system [21]). There is thus no obvious filter-feeding replacement for sardine in this ecosystem. This pattern was replicated in the energetic ocean context off Japan, where anchovies have not historically built populations comparable to those of sardines [64], and where the infestation of giant Nomura jellyfish has occurred following the collapse of what was an enormous Japanese sardine population [65]. When translocated ctenophores exploded in abundance following the anchovy collapse in the Black Sea [10], there was no obvious replacement. A similar episode of anchovy collapse and ctenophore explosion occurred in the Caspian Sea [43] and, following a similar general pattern, there was a decade-long increase in jellyfish abundance in the Bering Sea [55] following a lasting decline in herring abundance [66].

Equally informative are fishery collapses that have not led to jellyfish outbreaks. With the collapse of the largest fish stock in the world, the Peruvian anchoveta (Engraulis ringens) during the 1970s [64], there was no switch to increased jellyfish outbreaks. One possible explanation is that there were healthy stocks of an alternate rapidly responding filter-feeding species (i.e. highly migratory sardines) that quickly built up a large biomass and spread throughout the system to replace the collapsed anchoveta [64].

Finally, many of the instances in which fisheries collapses have not led to jellyfish outbreaks involve predatory rather than planktivorous fish [19]. Many fisheries collapses in the North Atlantic shelf and peripheral seas have been of bottom-dwelling predators such as cod and haddock. In these cases, the filter-feeding small pelagic prey of the collapsed species have increased rapidly (e.g. herring off New England [22] and sprat in the Baltic Sea [51]). Lower predatory fish biomass can release predation pressure on planktivorous fish, enabling their biomass to increase (top-down control) and, thus, lead to increased predation on, and competition with, jellyfish. Thus, many well-known collapses of piscivorous fish should have favoured increased planktivorous fish abundance and could have suppressed rather than encouraged jellyfish outbreaks.  ....

Thus, it is not unreasonable to suggest that jellyfish proliferations are held in check via a combination of competition for planktonic food and (perhaps) predation on ephyrae, small medusae or polyps by filter-feeding fishes. If this is the case, heavy fishing and other aspects of global change that appear to favour jellyfish could act to increase the abundance of jellyfish relative to that of filter-feeding fish until a crucial ‘tipping point’ [22,50,51] is reached. Here, jellyfish begin to overwhelm any significant control of their vulnerable life-cycle stages by fish predators, while progressively eliminating that control via their predation on fish eggs and larvae [52]. Moreover, as jellyfish abundance increases, successful sexual combination of planktonic reproductive products becomes more efficient. For jellyfish with entirely pelagic life cycles, this might involve infesting recirculating ocean currents, permanent eddy structures and other retention zones. For those species with obligate sessile stages, it might entail sequential colonisation of new seafloor habitat. A rapidly self-enhancing feedback loop could then ensue in which the jellyfish infestation spreads by sequentially invading habitats where fish might have formerly controlled jellyfish numbers.

Once established, a jellyfish infestation might quickly exclude competitive or predatory fish stocks, resulting in a durable regime shift in ecosystem structure and operation [51], with diverse fish communities replaced by a relative monoculture of jellyfish. As uncontrolled growth continues, local overproduction is available for export to new areas, where the jellyfish could again overwhelm resident predators and precipitate local outbreaks. ... This type of feedback mechanism, where the hunted becomes the hunter, is specific to marine environments, as illustrated by Bakun and Weeks [22]: ‘Imagine trying to maintain stability in an African veldt ecosystem if antelopes and zebras were to voraciously hunt and consume the young of the adult lions and cheetahs that prey on them.’ The potentially durable switch to a jellyfish- dominated system is reminiscent of the ancient, rudimentary ecosystems of the Cambrian, and has convinced some authors [26,53] that human stressors are propelling marine ecosystems ‘way back to the future’ (Box 3).

No News

Fern Prairie

I continue to be fascinated by fern prairies.  Turns out that one of the most common illustrations of Quetzalcoatlus northropi, an animal I've blogged about previously, is of it foraging on a fern prairie.

A group of flying reptiles called Quetzalcoatlus may have strolled along a fern prairie eating baby dinosaurs for lunch. Credit: Mark Witton, University of Portsmouth. (link)

Exotic Yard Animals

Shot at dusk with ISO 1600, also cropped quite a bit, so a bit grainy. Autofocus is also less reliable in low light and this may have some front focus.

We also had a coyote come come around and approach the kids while they were playing in the yard.  It took very quickly off when I showed up.  No photos though, and I could have got some it had figured out it was a coyote when it made a first pass on the street ten minutes earlier.  Could have been a stray coyote-like dog as well, especially since it seemed pretty large and muscular for a coyote. 

Shade intensive forests are a modern biome

I've been slowly assimilating the fact that shade intensive forests with a stratified closed canopy are a relatively modern biota.  In particular, modern ferns are not like ancient ferns since ancient ferns did not live in forests with deep shade. Instead, many ancient ferns were more like modern grasses, even forming 'fern prairies.'

For instance, Davis et.al., who support the earliest date for the origin of modern forests, survey the literature in Explosive Radiation of Malpighiales Supports a Mid-Cretaceous Origin of Modern Tropical Rain Forests, 2005:

Modern tropical rain forests are one of the most important and species rich biomes on the planet. They can be defined as having a stratified closed canopy, as receiving abundant precipitation, as experiencing equable temperatures, and as containing woody angiosperm species, at least in the understory (Richards 1996; Whitmore 1998; Morley 2000). During the past 20 years the view has become widespread that the expansion and diversification of this vegetation type occurred principally during the past 65 million years, following the mass extinction event at the Cretaceous- Tertiary (K/T) boundary (∼65 Ma [Tiffney 1984; Wing and Boucher 1998; Morley 2000; Johnson and Ellis 2002; Ziegler et al. 2003]; Cretaceous and Cenozoic timescales following Gradstein et al. [1995] and Berggren et al. [1995]). This hypothesis was initially supported by the rarity of large stems (Wheeler and Baas 1991; Wing and Boucher 1998) and large diaspores (Tiffney 1984; Wing and Boucher 1998) of angiosperms in the Cretaceous and by the marked increase in diaspore size in the Early Tertiary. Large seeds facilitate the establishment of seedlings under a rain forest canopy (Grime 1979).

Studies of fossil leaves and wood (Upchurch and Wolfe 1987, 1993; Wolfe and Upchurch 1987) partially corroborated this pattern by indicating that most Late Cretaceous floras of southern North America, which was tropical or nearly so, represented open and subhumid (though not deciduous) forests. This contrasts with fossil floras in the same areas after the recovery from the K/T extinction event, which resemble modern tropical rain forests (Wolfe and Upchurch 1987; Johnson and Ellis 2002). However, floras from the early Late Cretaceous (Cenomanian; ∼100 Ma) of Kansas, Nebraska, and New Jersey have leaf sizes and morphologies characteristic of wetter climates (Wolfe and Upchurch 1987). Upchurch and Wolfe (1993) interpreted one flora (Fort Harker, KS) as typical megathermal (>20C mean annual temperature [Upchurch and Wolfe 1987]) rain forest and as evidence against the view that such forests did not originate until the Tertiary.

Temperate intensive shade forests also appear to be extant only since the mid-Cretaceous at the earliest.  It is not clear to me yet what the standard theory is, except that the 'mid-Cretaceous is a period of sudden turnover from gymnosperm to angiosperm dominated floras' as Coiffard et. al. write.  As to causality, I cannot tell what is going on yet. 

But back to modern ferns for a moment:

Leptosporangiate ferns, with more than 9000 extant species, are truly exceptional among the non-flowering lineages of vascular plants. However, this rather remarkable diversity was not simply a consequence of being able to “hold on” as flowering plants rose to dominance. Instead, it appears to be the result of an ecological opportunistic response to the establishment of more complex, angiosperm-dominated ecosystems. The proliferation of flowering plants across the landscape undoubtedly resulted in the formation of a plethora of new niches into which leptosporangiate ferns could diversify. Many of these were evidently on shady forest floors, but many others were actually within the new angiosperm-dominated canopies. Today, almost one third of leptosporangiate species grow as epiphytes on angiosperm trees.

Finally, it seems the modern steppe with its highly productive heat tolerant grasses and occasional trees is an even more modern biome, just 8 or so million years old.  More later...

Random Yard Photos

I went for a walk in the yard with kid #3 taking photos.  Harder than one would think even with a kids who buys into the project. We have a huge number of Arisaema triphyllum, the second as well as the last plant below, in the back yard.  A native wet forest perennial and, apparently, deer resistant.

 

 

 

 

 

 

Yet More Late Quaternary Extinctions

Darren Naish writes:

[U]ntil just a few thousand years ago, small crocodilians inhabited the tropical islands of the South Pacific and elsewhere. In fact, judging from recent discoveries, small terrestrial crocodilians were an ordinary component of many tropical island groups, and they presumably still would be, had they not been made extinct by people.

More at the link. 

Annual Fern Photo

Here, belatedly, is my annual fern photo (see also 2006, 2008).   Shot on the run -- the kids needed to be fed -- in the yard this evening.   Still one of my favorite plants.  And why no commemorate the post KT global fern spike as well as the Triassic-Jurassic fern spike?

The most dominant land animal ever: Lystrosaurus

Lystrosaurus was one of the very few large survivors of the Permian mass extinctions.  More later....

Unintended Negative Effects of EU Biofuel Policy?

I need to find a much more detailed write-up of this claim:

Only recently have conservationists begun to grasp what a debacle it was to enact climate change legislation in Europe without first putting in place global deforestation treaties. EU policies promoting a market for biofuels triggered the destruction of Indonesian rain forests in favor of palm plantations.

Supposedly this more than offset any possible positive effects of these biofuel policies (which, within the framework of EU climate change legislation may already be close to zero or negative without taking trade related effects into account). 

In general, one of the big issues looming in climate policy is the trade induced effects if policy is not uniform across jurisdictions, as it is sadly bound to be.  Differential policies across jurisdictions can both drive up economic costs and lead to additional adverse environmental impacts. 

It would be good to know more....

Asian Deserts and Forests during the Last Glacial Maxium

Asia 18,000 years before present.  Note the extensive deserts and limited and regional forests.  Temperate forests are basically only in southern Japan and around the coast of the Yellow Sea. 

 

More Evil Deer

The Temperate Tropical Highlands

Well, I'm not finding a good high resolution climate map or maps to link to...basic point is that these places seem interesting for a variety of reasons, both ecologically and for human history. 

Dermacentor variabilis (Dog or Wood Tick)

My wife pulled this tick off kid #3 this morning, leaving the confirmation of her ID of it as a wood tick to me.  Yes, it does look like Dermacentor variabilis.  My wife took it off with a hot extinguished match head, used tweezers to pull out the rest, and put antibiotic ointment on the bite.  Not known to transmit Lyme Disease, but can carry other diseases.  (Shot with a point-ant-shoot with a macro setting with a dime for size) 

Recently Extinct Megafauna Update

Dennis M. Hansen and Mauro Galetti write in Science:

Scientists have argued that in continental Central and South America, the extinction of the classic mammalian megafauna--such as giant ground sloths and gomphotheres--caused disruption of seed dispersal for large fruits (4, 5). However, on islands, the extinction of large birds and reptiles in the past two or three millennia has led to similar disruptions (8, 9). ....
[T]he largest frugivores in South America were gomphoteres (7580 kg), whereas the largest living frugivores are the tapirs (300 kg). On the continental island of Madagascar, the role of largest frugivore has passed from the elephant bird (450 kg) to the radiated tortoise (10 kg). On Mauritius, giant tortoises weighing up to 100 kg were the largest native frugivores; today, the title goes to a fruitbat weighing only 0.54 kg. Thus, the loss of the island giants--tortoises, lizards, and flightless birds such as the dodo that were once found on many islands--has, in relative terms, led to a greater megafaunal downsizing than the extinction of even the largest gomphotheres in South America.  ....
If all currently threatened vertebrate frugivores were to go extinct, the relative ecological shrinkage in many continental ecosystems would equal that of islands. For instance, if all threatened frugivores in South America were to go extinct, the largest remaining frugivore would be the howler monkey, weighing 9 kg--a factor of 700 less than the giant ground sloth. Even some islands stand to suffer further losses; in Mauritius, the largest nonthreatened native frugivore is the gray white-eye, a bird weighing a mere 0.009 kg.

Here are two gomphotheres -- which did have overlap with humans, with many now extinct or marginal fruit plants specialized for dispersal via them (see Janzen 1982 and more critically Howe 1985).  BTW, this is part of the backdrop for the 'Rewildering North America' movement (see also a critique of the movement). 

Update #1: some examples of megafauna fruit (not clear if these are all from South America and I'm not going to spend time figuring it out):

Clouds

V. Ramanathan writes

Extra-tropical storm track cloud systems provide about 60% of the total cooling effect of clouds [6]. The annual mean forcing from these cloud systems is in the range of –45 to –55 W m–2 and effectively these cloud systems are shielding both the northern and the southern polar regions from intense radiative heating. Their spatial extent towards the tropics moves with the jet stream, extending farthest towards the tropics (about 35 deg latitude) during winter and retreating polewards (polewards of 50 deg latitude) during summer. This phenomenon raises an important question related to past climate dynamics.
During the ice age, due to the large polar cooling, the northern hemisphere jet stream extended more southwards. But have the extra tropical cloud systems also moved southward? The increase in the negative forcing would have exerted a major positive feedback on the ice age cooling. There is a curious puzzle about the existence of these cooling clouds. The basic function of the extra tropical dynamics is to export heat polewards.
While the baroclinic systems are efficient in transporting heat, the enormous negative radiative forcing (Fig. 2) associated with these cloud systems seems to undo the poleward transport of heat by the dynamics. The radiative effect of these systems is working against the dynamical effect. Evidently, we need better understaning of the dynamic- thermodynamic coupling between these enormous cooling clouds and the equator-pole temperature gradient, and greenhouse forcing.
Another major interesting feature in Fig. 2 is the smaller forcing over the highly reflective (high albedo) tropical cloud systems. It is well known that over the western tropical Pacific, equatorial Africa, South America, and the monsoon regions of Asia, deep cumulonimbus- cirrus systems give rise to extensive high albedo clouds, but Fig. 2 does not show this cooling effect. The fundamental reason is that the greenhouse effect of these cloud systems are very large (because their tops are located in the cold upper troposphere) and the large positive forcing from the cloud greenhouse effect nearly cancels out the large negative forcing from the high albedo of these clouds.  ...

While the atmospheric circulation determines the location and extent of clouds and water content, aerosols are the nuclei for cloud drops and thus determine the size and number distribution of cloud drops. The aerosol properties, in turn, are determined by the chemistry (e.g. oxidation of sulfur dioxide) and the biology (dimethyl sulfide and organics). The aerosol-cloud interactions in turn determine the precipitation efficiency of clouds and thus regulate lifetimes and spatial extent of clouds. All of these parameters including the aerosol concentration and composition undergo significant temporal (minutes to years) and spatial (meters to planetary scales) variations. It is remarkable that general circulation climate models (GCMs) are able to explain the observed temperature variations during the last century solely through variations in greenhouse gases, volcanoes and solar constant. This implies that the cloud contribution to the planetary albedo due to feedbacks with natural and forced climate changes has not changed during the last 100 years by more than ±0.3%; i.e, the cloud forcing has remained constant within ±1 Wm–2. If indeed, the global cloud properties and their influence on the albedo are this stable (as asserted by GCMs), scientists need to validate this prediction and develop a theory to account for the stability.

I'm not sure what Ramanathan means when he writes that "If indeed, the global cloud properties and their influence on the albedo are this stable (as asserted by GCMs), scientists need to validate this prediction and develop a theory to account for the stability" --- if the GCMs predict this, why do we need theory?  Better intuition might be helpful, but I don't see why we need a theory.  On the other hand, it would be nice to know if this stability is there outside of the 20th century, for times when we don't have good observational data and in which the models may break down.  For the most part, this seems like Ramanathan saying he doesn't trust the models here and thinks (correctly?) that the modeling community may have gotten lucky or fooled itself by calibrating models to get this fact just right without actually getting the physics right. 

Ramanathan was Chair of the NAS Committee on Strategic Advice on the US Climate Change Science Program, so he has some standing. 

Half of all mammal species heavier than 100 lbs extinct

Barry Brook writes introducing one of his papers on the the relative contribution of people and climate in driving the late Pleistocene and Holocene megafauna extinctions:

End-Quaternary (late Pleistocene and Holocene) extinctions eliminated half of all mammal species heavier than 44 kg (100 lbs) and other large-bodied fauna across most continents (Australia, Eurasia, North and South America) and large islands (West Indies, Madagascar and New Zealand), between 50,000 and 600 years before present. The losses included large mammals (e.g., mammoth, giant wombats), reptiles (e.g. huge monitor lizards about three times bigger than Komodo dragons), and massive flightless birds (e.g. moa, Elephant birds).

Greenhouse Effect History of Thought

One argument that shows up in global warming denial discourse is that CO2 cannot matter since a) CO2 is an efficient absorber of IR radiation and adding more CO2 cannot make the greenhouse blanket over the earth any thicker, b) CO2 absorbs in the same spectral bands as water, so again adding more CO2 cannot matter.  In short, CO2 and water do create a greenhouse effect, but it cannot be pushed further by more CO2. 

An interesting aspect of this is that exactly these objections kept the initial global warming theory of Svante Arrhenius from becoming established science back around 1900 (even though Arrhenius did win the Nobel Prize for Chemistry in 1903 and had a good platform to work from, even writing a popularizing book on the topic).  In particular, as described in an AIP retrospective:

Experts could dismiss the hypothesis because they found Arrhenius's calculation implausible on many grounds. In the first place, he had grossly oversimplified the climate system. Among other things, he had failed to consider how cloudiness might change if the Earth got a little warmer and more humid.(6) A still weightier objection came from a simple laboratory measurement. A few years after Arrhenius published his hypothesis, another scientist in Sweden, Knut Ångström, asked an assistant to measure the passage of infrared radiation through a tube filled with carbon dioxide. The assistant ("Herr J. Koch," otherwise unrecorded in history) put in rather less of the gas in total than would be found in a column of air reaching to the top of the atmosphere. The assistant reported that the amount of radiation that got through the tube scarcely changed when he cut the quantity of gas back by a third. Apparently it took only a trace of the gas to "saturate" the absorption — that is, in the bands of the spectrum where CO2 blocked radiation, it did it so thoroughly that more gas could make little difference.(7*)

Still more persuasive was the fact that water vapor, which is far more abundant in the air than carbon dioxide, also intercepts infrared radiation. In the crude spectrographs of the time, the smeared-out bands of the two gases entirely overlapped one another. More CO2 could not affect radiation in bands of the spectrum that water vapor, as well as CO2 itself, were already blocking entirely.(8)

These measurements and arguments had fatal flaws. Herr Koch had reported to Ångström that the absorption had not been reduced by more than 0.4% when he lowered the pressure, but a modern calculation shows that the absorption would have decreased about 1% — like many a researcher, the assistant was over confident about his degree of precision.(8a) But even if he had seen the1% shift, Ångström would have thought this an insignificant perturbation. He failed to understand that the logic of the experiment was altogether false.

The greenhouse effect will in fact operate even if the absorption of radiation were totally saturated in the lower atmosphere. The planet's temperature is regulated by the thin upper layers where radiation does escape easily into space. Adding more greenhouse gas there will change the balance. Moreover, even a 1% change in that delicate balance would make a serious difference in the planet’s surface temperature. The logic is rather simple once it is grasped, but it takes a new way of looking at the atmosphere — not as a single slab, like the gas in Koch's tube (or the glass over a greenhouse), but as a set of interacting layers.

As the AIP retrospective explains in a separate section:

Not until the mid-20th century would scientists fully grasp, and calculate with some precision, just how the effect works. A rough explanation goes like this. Visible sunlight penetrates easily through the air and warms the Earth’s surface. When the surface emits invisible infrared heat radiation, this radiation too easily penetrates the main gases of the air. But as Tyndall found, even a trace of CO2, no more than it took to fill a bottle in his laboratory, is almost opaque to heat radiation. Thus a good part of the radiation that rises from the surface is absorbed by CO2 in the middle levels of the atmosphere. Its energy transfers into the air itself rather than escaping directly into space. Not only is the air thus warmed, but also some of the energy trapped there is radiated back to the surface, warming it further.

That’s a shorthand way of explaining the greenhouse effect — seeing it from below, from "inside" the atmosphere. Unfortunately, shorthand arguments can be misleading if you push them too far. Fourier, Tyndall and most other scientists for nearly a century used this approach, looking at warming from ground level, so to speak, asking about the radiation that reaches and leaves the surface of the Earth. So they tended to think of the atmosphere overhead as a unit, as if it were a single sheet of glass. (Thus the "greenhouse" analogy.) But this is not how global warming actually works, if you look at the process in detail.

What happens to infrared radiation emitted by the Earth's surface? As it moves up layer by layer through the atmosphere, some is stopped in each layer. (To be specific: a molecule of carbon dioxide, water vapor or some other greenhouse gas absorbs a bit of energy from the radiation. The molecule may radiate the energy back out again in a random direction. Or it may transfer the energy into velocity in collisions with other air molecules, so that the layer of air where it sits gets warmer.) The layer of air radiates some of the energy it has absorbed back toward the ground, and some upwards to higher layers. As you go higher, the atmosphere gets thinner and colder. Eventually the energy reaches a layer so thin that radiation can escape into space. What happens if we add more carbon dioxide? In the layers so high and thin that much of the heat radiation from lower down slips through, adding more greenhouse gas means the layer will absorb more of the rays. So the place from which most of the heat energy finally leaves the Earth will shift to higher layers. Those are colder layers, so they do not radiate heat as well. The planet as a whole is now taking in more energy than it radiates (which is in fact our current situation). As the higher levels radiate some of the excess downwards, all the lower levels down to the surface warm up. The imbalance must continue until the high levels get warmer and radiate out more energy. As in Tyndall's analogy of a dam on a river, the barrier thrown across the outgoing radiation forces the level of temperature everywhere beneath it to rise until there is enough radiation pushing out to balance what the Sun sends in.

While that may sound fairly simple once it is explained, the process is not obvious if you have started by thinking of the atmosphere from below as a single slab. The correct way of thinking eluded nearly all scientists for more than a century after Fourier. Physicists learned only gradually how to describe the greenhouse effect. To do so, they had to make detailed calculations of a variety of processes in each layer of the atmosphere.

Finally:

The subtle difference did not occur to anyone for many decades, if only because hardly anyone thought the greenhouse effect was worth their attention. For after Ångström published his conclusions in 1900, the few scientists who had taken an interest in the matter concluded that Arrhenius's hypothesis had been proven wrong. Theoretical work on the question stagnated for decades, and so did measurement of the level of CO2 in the atmosphere.(9)

A few scientists dissented from the view that changes of CO2 could have no effect. An American physicist, E.O. Hulburt, pointed out in 1931 that investigators had been mainly interested in pinning down the intricate structure of the absorption bands (which offered fascinating insights into the new theory of quantum mechanics) "and not in getting accurate absorption coefficients." Hulburt's own calculations supported Arrhenius's estimate that doubling or halving CO2 would bring something like a 4°C rise or fall of surface temperature, and thus "the carbon dioxide theory of the ice ages... is a possible theory."(10*) Hardly anyone noticed this paper. Hulburt was an obscure worker at the U.S. Naval Research Laboratory, and he published in a journal, the Physical Review, that few meteorologists read. Their general consensus was the one stated in such authoritative works as the American Meteorological Society's 1951 Compendium of Meteorology: the idea that adding CO2 would change the climate "was never widely accepted and was abandoned when it was found that all the long-wave radiation [that would be] absorbed by CO2 is [already] absorbed by water vapor."(11)

Or as James R. Fleming writes:

By 1929, G.C. Simpson had pointed out that it was "now generally accepted that variations in carbon-dioxide in the atmosphere, even if they do occur, can have no appreciable effect on the climate." Simpson provided three reasons why this was so: (1) The absorption band of carbon dioxide is too narrow to have a significant effect on terrestrial radiation; (2) The current amount of atmospheric carbon dioxide exerts its full effect and any further addition would have little or no influence; and (3) The water vapor absorption band overlaps and dominates the carbon dioxide band. Such negative assessments of the carbon dioxide theory reached wide audiences through articles on climate change in the U.S.D.A. Yearbook for 1941 and in the Compendium of Meteorology in 1951.

After a few isolated pre-WWII attempts at figuring out how atmospheric radiative equilibrium worked, WWII and especially the early Cold War with the needs of the Air Force and military funding for research lead researchers, including astrophysicists, to start figuring out how multilayer models of the atmosphere work. 

Update #1: I've been looking for a nice popular write up of how the greenhouse effect responds to CO2 forcing in terms of how it raises the emission height at the tropopause...but annoyingly, I cannot find one.  Nor can I find my standard Climate Modeling book in my basement, though I did find Thomas and Stamnes, Radiative Transfer in Atmosphere and Ocean.  But they don't seem to have short intuitive treatment.  

Climate Change Link Dump

David Archer & Victor Brovkin, The millennial atmospheric lifetime of anthropogenic CO2, Climatic Change (2008)

The notion is pervasive in the climate science community and in the public at large that the climate impacts of fossil fuel CO2 release will only persist for a few centuries. This conclusion has no basis in theory or models of the atmosphere/ocean carbon cycle, which we review here. The largest fraction of the CO2 recovery will take place on time scales of centuries, as CO2 invades the ocean, but a significant fraction of the fossil fuel CO2, ranging in published models in the literature from 20–60%, remains airborne for a thousand years or longer. Ultimate recovery takes place on time scales of hundreds of thousands of years, a geologic longevity typically associated in public perceptions with nuclear waste. The glacial/interglacial climate cycles demonstrate that ice sheets and sea level respond dramatically to millennial-timescale changes in climate forcing. There are also potential positive feedbacks in the carbon cycle, including methane hydrates in the ocean, and peat frozen in permafrost, that are most sensitive to the long tail of the fossil fuel CO2 in the atmosphere.

Alvaro Montenegro et.al., Long term fate of anthropogenic carbon, Geophy Res Let 2007

Two earth-system models of intermediate complexity are used to study the long term response to an input of 5000 Pg of carbon into the atmosphere. About 75% of CO2 emissions have an average perturbation lifetime of 1800 years and 25% have lifetimes much longer than 5000 years. In the simulations, higher levels of atmospheric CO2 remain in the atmosphere than predicted by previous experiments and the average perturbation lifetime of atmospheric CO2 for this level of emissions is much longer than the 300–400 years proposed by other studies. At year 6800, CO2 concentrations between about 960 to 1440 ppmv result in global surface temperature increases between 6C and 8C. There is also significant surface ocean acidification, with pH decreasing from 8.16 to 7.46 units between years 2000 and 2300.

Gerard H. Roe and Marcia B. Baker, Why Is Climate Sensitivity So Unpredictable? Science 2007 [supporting material]

Uncertainties in projections of future climate change have not lessened substantially in past decades. Both models and observations yield broad probability distributions for long-term increases in global mean temperature expected from the doubling of atmospheric carbon dioxide, with small but finite probabilities of very large increases. We show that the shape of these probability distributions is an inevitable and general consequence of the nature of the climate system, and we derive a simple analytic form for the shape that fits recent published distributions very well. We show that the breadth of the distribution and, in particular, the probability of large temperature increases are relatively insensitive to decreases in uncertainties associated with the underlying climate processes.

Reto Knutti and Gabriele C. Hegerl, The equilibrium sensitivity of the Earth’s temperature to radiation changes, Nature Geoscience 2008

The Earth’s climate is changing rapidly as a result of anthropogenic carbon emissions, and damaging impacts are expected to increase with warming. To prevent these and limit long-term global surface warming to, for example, 2 °C, a level of stabilization or of peak atmospheric CO2 concentrations needs to be set. Climate sensitivity, the global equilibrium surface warming after a doubling of atmospheric CO2 concentration, can help with the translation of atmospheric CO2 levels to warming. Various observations favour a climate sensitivity value of about 3 °C, with a likely range of about 2–4.5 °C. However, the physics of the response and uncertainties in forcing lead to fundamental difficulties in ruling out higher values. The quest to determine climate sensitivity has now been going on for decades, with disturbingly little progress in narrowing the large uncertainty range. However, in the process, fascinating new insights into the climate system and into policy aspects regarding mitigation have been gained. The well-constrained lower limit of climate sensitivity and the transient rate of warming already provide useful information for policy makers. But the upper limit of climate sensitivity will be more difficult to quantify.

Margaret B. Davis and Ruth G. Shaw, Range Shifts and Adaptive Responses to Quaternary Climate Change, Science 2001

Tree taxa shifted latitude or elevation range in response to changes in Quaternary climate. Because many modern trees display adaptive differentiation in relation to latitude or elevation, it is likely that ancient trees were also so differentiated, with environmental sensitivities of populations throughout the range evolving in conjunction with migrations. Rapid climate changes challenge this process by imposing stronger selection and by distancing populations from environments to which they are adapted. The unprecedented rates of climate changes anticipated to occur in the future, coupled with land use changes that impede gene ßow, can be expected to disrupt the interplay of adaptation and migration, likely affecting productivity and threatening the persistence of many species.

Petit et. al., Glacial Refugia: Hotspots But Not Melting Pots of Genetic Diversity, Science 2003

Glacial refuge areas are expected to harbor a large fraction of the intraspecific biodiversity of the temperate biota. To test this hypothesis, we studied chloroplast DNA variation in 22 widespread European trees and shrubs sampled in the same forests. Most species had genetically divergent populations in Mediterranean regions, especially those with low seed dispersal abilities. However, the genetically most diverse populations were not located in the south but at intermediate latitudes, a likely consequence of the admixture of divergent lineages colonizing the continent from separate refugia.

Godfrey Hewitt, The genetic legacy of the Quaternary ice ages, Nature 2000

Global climate has fluctuated greatly during the past three million years, leading to the recent major ice ages. An inescapable consequence for most living organisms is great changes in their distribution, which are expressed differently in boreal, temperate and tropical zones. Such range changes can be expected to have genetic consequences, and the advent of DNA technology provides most suitable markers to examine these. Several good data sets are now available, which provide tests of expectations, insights into species colonization and unexpected genetic subdivision and mixture of species. The genetic structure of human populations may be viewed in the same context. The present genetic structure of populations, species and communities has been mainly formed by Quaternary ice ages, and genetic, fossil and physical data combined can greatly help our understanding of how organisms were so affected.

John W Williams and Stephen T Jackson, Novel climates, no-analog communities, and ecological surprises, Front Ecol Environ 2007;

No-analog communities (communities that are compositionally unlike any found today) occurred frequently in the past and will develop in the greenhouse world of the future. The well documented no-analog plant communities of late-glacial North America are closely linked to “novel” climates also lacking modern analogs, characterized by high seasonality of temperature. In climate simulations for the Intergovernmental Panel on Climate Change A2 and B1 emission scenarios, novel climates arise by 2100 AD, primarily in tropical and subtropical regions. These future novel climates are warmer than any present climates globally, with spatially variable shifts in precipitation, and increase the risk of species reshuffling into future no-analog communities and other ecological surprises. Most ecological models are at least partially parameterized from modern observations and so may fail to accurately predict ecological responses to these novel climates. There is an urgent need to test the robustness of ecological models to climate conditions outside modern experience.

Stephen T. Jackson and Chengyu Weng, Late Quaternary extinction of a tree species in eastern North America, PNAS 1999

Widespread species- and genus-level extinctions of mammals in North America and Europe occurred during the last deglaciation [16,000–9,000 yr B.P. (by 14C)], a period of rapid and often abrupt climatic and vegetational change. These extinctions are variously ascribed to environmental change and overkill by human hunters. By contrast, plant extinctions since the Middle Pleistocene are undocumented, suggesting that plant species have been able to respond to environmental changes of the past several glacialy interglacial cycles by migration. We provide evidence from morphological studies of fossil cones and anatomical studies of fossil needles that a now-extinct species of spruce (Picea critchfieldii sp. nov.) was widespread in eastern North America during the Last Glacial Maximum. P. critchfieldii was dominant in vegetation of the Lower Mississippi Valley, and extended at least as far east as western Georgia. P. critchfieldii disappeared during the last deglaciation, and its extinction is not directly attributable to human activities. Similarly widespread plant species may be at risk of extinction in the face of future climate change.

C.W. Woodall at. al., An indicator of tree migration in forests of the eastern United States, Forest Ecology and Management 2009

Changes in tree species distributions are a potential impact of climate change on forest ecosystems. The examination of tree species shifts in forests of the eastern United States largely has been limited to simulation activities due to a lack of consistent, long-term forest inventory datasets. The goal of this study was to compare current geographic distributions of tree seedlings (trees with a diameter at breast height <2.5 cm) with biomass (trees with a diameter at breast height > 2.5 cm) for sets of northern, southern, and general tree species in the eastern United States using a spatially balanced, region-wide forest inventory. Compared to mean latitude of tree biomass, mean latitude of seedlings was significantly farther north (>20 km) for the northern study species, while southern species had no shift, and general species demonstrated southern expansion. Density of seedlings relative to tree biomass of northern tree species was nearly 10 times higher in northern latitudes compared to southern latitudes. For forest inventory plots between 448 and 478 north latitude where southern tree species were identified, their biomass averaged 0.46 tonnes/ha while their seedling counts averaged 2600 ha-1. It is hypothesized that as northern and southern tree species together move northward due to greater regeneration success at higher latitudes, general species may fill their vacated niches in southern locations. The results of this study suggest that the process of northward tree migration in the eastern United States is currently underway with rates approaching 100 km/century for many species.

Global Warming Commitment by Emissions up to Today

The standard models indicate that the long-persistence fraction of emissions already made up to today commits us to global warming for the long-run, most of which is not yet realized.  See, for instance, the first graph in Ramanathan and Feng, On avoiding dangerous anthropogenic interference with the climate system: Formidable challenges ahead, PNAS 2008, showing the probability distribution for current models of where we'll end up if we stop emitting today.  Note the list of threshold temperatures for different effects.  I've not figured out what long-term feedbacks are included or excluded here.  For instance, I suspect changes in the themohaline circulation or the cores of large ice sheets aren't included, and some vegetation changes may also be excluded.  And this just emissions up to now -- we could put four times this amount into the air in the next 100 years.  [See also Susan Solomon, Gian-Kasper Plattner, Reto Knutti, and Pierre Friedlingstein, Irreversible climate change due to carbon dioxide emissions, PNAS 2009, which puts assumptions in Ramanathan and Feng in context. Hans Joachim Schellnhuber, Global warming: Stop worrying, start panicking? discusses Ramanathan and Feng.  Finally, Timothy M. Lenton et. al., Tipping elements in the Earth’s climate system, PNAS 2008.]

Climate Change

I'm on a climate change reading binge, with several preliminary observations that might be interesting to blog about, but learning quite a bit about the literature is keeping me busy enough.

My gut feeling on going into this reading binge is that insufficient attention is paid to long-run --  meaning more than 100 or more than 1000 year -- effects of carbon emissions today, given the long persistence of CO2 in the climate system (about 25% of carbon emitted into the atmosphere persists as a higher carbon concentration in the atmosphere 10,000 years out in standard models), bad tail effects, given the difficulty of ruling out high climate sensitivities with all feedbacks asymptotically (the standard quoted sensitivity appears to be for a medium range sensitivity excluding slow feedbacks [1]). In terms of my policy preferences I don't really care much about what the climate change in the next few decades is going to be, except to the extent we learn about the earth's behavior and the political effects this has, since these effects are relatively small and mostly predetermined by now compared to what might be coming later.  I also have the sense that a bit of well mitigated warming might not even be bad, but after a bit of warming things will get much more interesting and may have big downsides that are much harder to adapt to. 

[1] See Gavin Schmidt:

First, it probably needs to be made clearer that generally speaking radiative forcing and climate sensitivity are useful constructs that apply to a subsystem of the climate and are valid only for restricted timescales - the atmosphere and upper ocean on multi-decadal periods. This corresponds in scope (not un-coincidentally) to the atmospheric component of General Circulation Models (GCMs) coupled to (at least) a mixed-layer ocean. For this subsystem, many of the longer term feedbacks in the full climate system (such as ice sheets, vegetation response, the carbon cycle) and some of the shorter term bio-geophysical feedbacks (methane, dust and other aerosols) are explicitly excluded. Changes in these excluded features are therefore regarded as external forcings.

Why this subsystem? Well, historically it was the first configuration in which projections of climate change in the future could be usefully made. More importantly, this system has the very nice property that the global mean of instantaneous forcing calculations (the difference in the radiation fluxes at the tropopause when you change greenhouse gases or aerosols or whatever) are a very good predictor for the eventual global mean response. It is this empirical property that makes radiative forcing and climate sensitivity such useful concepts. For instance, this allows us to compare the global effects of very different forcings in a consistent manner, without having to run the model to equilibrium every time.

Which means there might be some nasty non-linear action in the longer term feedbacks.  Also note that sensitivities look like s = 1/(1-f_1 - f_2 - ...), so even small additional long-run feedbacks start becoming important once medium-run sensitivity is already high, so non-linearities are pretty much globally built in here. I need to look into this more to see if I have this right.

Schmidt continues:

To see why a more expansive system may not be as useful, we can think about the forcings for the ice ages themselves. These are thought to be driven by the large regional changes in insolation driven by orbital changes. However, in the global mean, these changes sum to zero (or very close to it), and so the global mean sensitivity to global mean forcings is huge (or even undefined) and not very useful to understanding the eventual ice sheet growth or carbon cycle feedbacks. ....

So in order to constrain the climate sensitivity from the paleo-data, we need to find a period under which our restricted subsystem is stable - i.e. all the boundary conditions are relatively constant, and the climate itself is stable over a long enough period that we can assume that the radiation is pretty much balanced. The last glacial maximum (LGM) fits this restriction very well, and so is frequently used as a constraint. From at least Lorius et al (1991) - when we first had reasonable estimates of the greenhouse gases from the ice cores, to an upcoming paper by Schneider von Deimling et al, where they test a multi-model ensemble (1000 members) against LGM data to conclude that models with sensitivities greater than about 4.3ºC can't match the data. In posts here, I too have used the LGM constraint here to demonstrate why extremely low (< 1ºC) or extremely high (> 6ºC) sensitivities can probably be ruled out.

But extremely high sensitivities are ruled out only if 'all the boundary conditions are relatively constant'.  Which begs the question of what the long-run effects that we are committing ourselves to now are. And to the extent the relevant boundary conditions are going to change, they are going to change in a direction the earth system hasn't explored for at least 4 million years, a warmer earth that has a different geography (i.e. sufficiently different ocean basins, especially in the arctic, and sufficiently different mountain ranges, especially Himalayan height) than when it last encountered these temperatures and CO2 forcings. We know what this earth does when it gets colder and can assess climate sensitivities with some confidence based on historical data.  More than 1C warmer -- or are we there already? -- and we're in different territory. 

The Green Wet Sahara

One thing you'll notice if you look at the world map of forest cover and extreme desert during the last glacial maximum from my post yesterday is that the Sahara is, well, extreme desert, more extreme than today extending further south.  So when was the green wet Sahara of lore? 

Turns out the 'green wet Sahara' -- not that green, green here means savannah and not desert --  was in the period immediately after the Ice age until before the beginnings of Ancient Egypt. See for instance Rudolph Kuper and Stefan Kropelin, Climate-Controlled Holocene Occupation in the Sahara: Motor of Africa’s Evolution, Science 2006:

Radiocarbon data from 150 archaeological excavations in the now hyper-arid Eastern Sahara of Egypt, Sudan, Libya, and Chad reveal close links between climatic variations and prehistoric occupation during the past 12,000 years. Synoptic multiple-indicator views for major time slices demonstrate the transition from initial settlement after the sudden onset of humid conditions at 8500 B.C.E. to the exodus resulting from gradual desiccation since 5300 B.C.E. Southward shifting of the desert margin helped trigger the emergence of pharaonic civilization along the Nile, influenced the spread of pastoralism throughout the continent, and affects sub-Saharan Africa to the present day.  ...

During the Allerod interstadial (about 11,900 to 10,800 B.C.E.), when Northwest Europe witnessed temporarily waning ice sheets, and the following Younger Dryas, the final cold phase of the Pleistocene, the Eastern Sahara was still void of any aquatic environments and as hyper-arid as it was during the Last Glacial Maximum at 20,000 B.C.E. The first signal of a changing climate occurred in the early Preboreal with the establishment of postglacial conditions in the mid-latitudes, supported by evidence of a sudden appearance of carbonate lake formations in the Sudanese Sahara and of siliceous mud deposits in the Egyptian Sahara.
Radiocarbon dates of the base levels of these paleolakes and playa-type rain pools reveal the almost contemporaneous onset of pluvial conditions between latitudes 16-N and 24-N at about 8500 B.C.E., indicating an abrupt northward shift of the tropical rainfall belts over as much as 800 km within just several generations (7, 8). This decisive climate change can be attributed to tropical summer rains owing to a major extension of the paleomonsoon system, whereas the contribution of Mediterranean winter rain systems north of 24-N remains vague. As a result, notably improved environmental conditions spread over the entire Eastern Sahara (7–15), with semihumid climates in its southern part and semi-arid conditions in its center.

One question, which I'll try to discuss later, is why we are not, it seems, seeing a wetter Sahara now, if only briefly, with increased CO2 climate forcing, reversing the drying of the Sahara since 5,300 BCE that accompanied global cooling since that time.   

Update #1: see also S. Kröpelin et. al. Climate-Driven Ecosystem Succession in the Sahara: The Past 6000 Years, Science 206. 

Update #2: Timothy M. Lenton et. al., Tipping elements in the Earth’s climate system, PNAS 2008 discusses the future:

Sahara/Sahel and West African Monsoon (WAM). Past greening of the Sahara occurred in the mid-Holocene (71–73) and may have happened rapidly in the earlier Bo¨lling-Allerod warming. Collapse of vegetation in the Sahara 5,000 years ago occurred more rapidly than orbital forcing (71, 72). The system has been modeled and conceptualized in terms of bistable states that are maintained by vegetation–climate feedback (71, 74). However, it is intimately tied to the WAM circulation, which in turn is affected by sea surface temperatures (SSTs), particularly antisymmetric patterns between the Hemispheres. Greenhouse gas forcing is expected to increase the interhemispheric SST gradient and thereby increase Sahel rainfall; hence, the recent Sahel drought has been attributed to increased aerosol loading cooling the Northern Hemisphere (75). Future 21st century projections differ (75, 76); in two AOGCMs, the WAMcollapses, but in one this leads to further drying of the Sahel, whereas in the other it causes wetting due to increased inflow from the West. The latter response is more mechanistically reasonable, but it requires a 3°C warming of SSTs in the Gulf of Guinea (76). A third AOGCM with the most realistic present-day WAM predicts no large trend in mean rainfall but a doubling of the number of anomalously dry years by the end of the century (76). If the WAM is disrupted such that there is increased inflow from the West (76), the resulting moisture will wet the Sahel and support greening of the Sahara, as is seen in mid-Holocene simulations (73). Indeed, in an intermediate complexity model, increasing atmospheric CO2 has been predicted to cause future expansion of grasslands into up to 45% of the Sahara, at a rate of up to 10% of Saharan area per decade (11). In the Sahel, shrub vegetation may also increase due to increased water use efficiency (stomatal closure) under higher atmospheric CO2 (77). Such greening of the Sahara/Sahel is a rare example of a beneficial potential tipping element.

Forest Cover during the Last Glacial Maximum

I'd not realized how little forest cover there was during the last glacial maximum, worldwide and especially in Europe.(image below, also here)  Very small forest enclaves in the Southern Alps (or their foothills) and Carpathia, from which Europe's forests were  recolonized.  I do remember reading a few times that the ecological communities of today did not exist during the LGM and assembled from different sources afterward, instead of migrating together.  Conversely, ecological communities of the LGM don't exist today. It wold be nice to know more. 

Also note the massive reduction in forest cover in the Amazon and Africa. 

Ah, here is more:

Some areas of woodland present. In southern Europe, some areas of open pine (Pinus) and birch (Betula) woodland seem to have existed in the plains of northern Italy and to the south-east of the Alps, although these were not extensive (C. Tzedakis, August 1995). Scattered pockets of woodland or isolated trees occurred through the mid-altitudes (e.g. with a belt about 500m above [present] sea level in Northern Greece) of the southern Balkans and Apennines, according to reviews of the pollen evidence by van Zeist & Bottema (1982), Bennett et al. (1990) and Willis (1994). S. Bottema (pers. comm. April 1996) suggests from the pollen diagrams that the refugia for deciduous and needle-leaved species were mainly on the western side of the Mountains of Greece.

In the Balkans, the several scattered pollen sites indicate that the predominant vegetation was an open Artemisia steppe with a small component of Pinus, but with many other tree taxa present and locally abundant at mid elevations (around 500m altitude), possibly due to the orographic rainfall and reduced evaporation supplying just enough moisture to enable them to survive.

In Iberia, scattered patches of pine woodland may have been present in valleys and other sheltered sites in the mountains of Spain (Turner & Hannon 1988), showing up to some extent in the pollen diagrams. Yet although a Pinus and Quercus element was present, it seems to have been only locally important. For the most part, the LGM vegetation of Spain and Portugal seems to have been drought-tolerant, open and semi-desert or steppe-like, with abundant Artemisia, and also chenopods and grasses. Several cores scattered around the Iberian peninsula and off the south-west coast all indicate the same general vegetation type (Hooghiemstra et al. 1992). The most recently published core confirms the same picture of an almost treeless cold-tolerant, arid steppe for the region close to the Mediterranean, inland from Barcelona in the north-east of Spain (Pérez-Obiol & Julià 1994). In the south-west of Spain, the vegetation on the exposed continental shelf areas seems to have been sparse enough to allow extensive dune mobility at the LGM (Zazo pers. comm., May 1994), even well inland from coastal areas. In south-eastern Spain, sparse vegetation cover and semi-arid conditions punctuated by sudden storms are indicated by slope wash deposits which are thought to date from the last glacial (Harvey 1984). ...

Scattered pockets of woodland. The Caucuses is thought to have been a glacial refuge for many temperate tree taxa, although there is little direct evidence of these trees surviving there during the LGM. In the Colchis region of Southern Russia, along the eastern shores of the Black Sea and the high ranges of the Caucuses, pollen evidence indicates that there were scattered pine and birch forests but broad-leaved trees were probably very localised in distribution (Tumajanov 1971). In contrast to the large area of surviving forest suggested in the maps Grichuk (1980, 1992), Velichko & Kurenkova (1990) and Frenzel (1992) also show only small areas of closed temperate forest surviving in the lowlands of the southern Caucasus, with dry steppe and open woodlands or localised woody pockets prevailing. The map by van Zeist & Bottema (1988) similarly suggests that there was virtually no temperate forest present in the main Caucasus region at the LGM. It is not clear from these sources what evidence is used to justify this choice of vegetation types or to what extent more recent research on this area has been published.

Update #1: Paul Colinvaux believes there was extensive forest cover in the Amazonian lowlands during the LGM.  I cannot judge this issue....Colinvaux also appears just to have come out with a popular book on this. Yes, other recent papers seem to reflect a shift since the mid-1990s towards a more continuous forest cover view of the LGM Amazon, though still reduced compared to modern times by measures other than area, for instance here:

Although there are very few palaeoecological records extending to the LGM, there is accumulating evidence to indicate that most of the Amazon Basin was forested at this time (Fig. 1), contrary to Haffer’s (1969) hypothesis of widespread savanna with isolated, disjunct forest refugia. Colinvaux et al. (1996) and Bush et al. (2002) have provided pollen, sedimentological, and geochemical data that show that the Lake Pata catchment in the central Amazon (0816VN, 66841VW) was continuously forested over the last 170,000 years. De Freitas et al. (2001) collected soil carbon isotope data from a 200 km transect, spanning small, isolated pockets (ca. 10–100 km2) of seasonally flooded savannas, between Porto Velho (Rondonia State) and Humaita (Amazonas State), Brazil, between the coordinates 8843VS, 63858VW and 7838VS, 63804VW. These savanna dislandsT are surrounded by rainforest and located ca. 450 km north of the southern limit of rainforest communities in Bolivia. De Freitas et al. show that these savanna islands at 17 14C ka BP (ca. 20.5 cal ka BP) were no larger than today, indicating that there was no expansion of savanna at the expense of forest at this time.

The Historic Tidelands of the New York New Jersey Harbor Estuary

From a lost time. Especially impressive how much of the tidelands in New Jersey are no longer there. And this isn't all wetlands, just tidelands.  New Jersey was once, it seems, more than 30% wetlands. So that's what the Meadowlands are were about. 

Also, what processes maintain two exits for the Hudson River?  Why is there both an East River and an Upper New York Bay exit known as The Narrows?  Wouldn't sedimentation naturally close one or the other exit?  What prevents this (or prevented this before 1600)?  Or did the East River close at times since the Ice Age?    

(link)

Update #1: also surprising -- and it would be nice to know more -- it seems that there is not much recent sedimentation at the mouth of the Hudson:

"The Hudson has gone through many stages of evolution," said Cecilia M. G. McHugh, the lead scientist on the study being published in an upcoming issue of the journal Geology. "Now it's entering a new phase." Some new deposits are being laid down as a result of annual rise in sea level, McHugh continued, but on the whole, the river is at equilibrium.

Every year the Hudson tributaries to the north discharge sand and silt into the river. The sand is trapped around islands and shoals near Kingston, while the silt washes down into the Hudson River Estuary, filling areas where scouring or dredging has occurred. Most of the silt is being trapped in a section of the river near the George Washington Bridge known as the Estuarine Turbidity Maximum (ETM). A small amount of silt is also being washed out to areas around the mouth of the Lower New York Bay.

The valley that the Hudson River occupies is a deep gouge in the bedrock that geologists believe was formed over the course of tens of millions of years. During the last glacial maximum nearly 18,000 years ago, the valley was filled with ice from the Laurentide glacier. As the glacier receded, ice and melt water formed a series of interconnected lakes in the valley that eventually merged to form the Hudson River. The valley filled with river sediments for nearly 3,000 years until sea level rose and the river merged with the encroaching Atlantic Ocean forming the Hudson River Estuary.

The estuary, the section of river where river and ocean water mix and that rises and falls with the tide, formed nearly 6,000 years ago. In places, sediment deposits beneath the estuary are more than 700 feet thick. Previously it was thought that this process of sedimentation was continuing today.

However, McHugh and her colleagues believe that accumulation ceased some time in the last 3,000-1,000 years. The researchers examined more than 100 two-meter-long sediment cores taken from the estuary and bay as well as high-resolution sonar and seismic imagery of the bottom. They found that the current rate of sedimentation in the estuary as a whole is approximately 1mm per year — about the same rate as sea level rise, which, together with scouring or dredging are the only processes that are providing space for new sediment in much of the estuary.

Farmed Tuna?

Last week's Nature had a news article that implied as an aside that tuna are now fish farmed, with the worst fish-in fish-out ratio for farmed fish.  But my first reaction was: how can a fish like tuna be farmed? 

Some methods do appear to be as one would suspect, for instance the Economist writes:

Perhaps the most grotesque form of fish farming is the ranching of bluefin tuna, a delicacy that may sell for as much as $860 a kilo. Bluefins are sensitive creatures that hate being cooped up so much that, if confined, they tend to throw themselves against their cages and break their necks. Australian “ranchers” have now adopted a technique that involves catching young bluefins, enveloping them in a huge net and dragging it slowly round the south seas for months while feeding them pilchards imported from west Africa.

I found some more stuff on this googling around, but no definite account.  More than half of all bluefin tuna sold in the world appears to go through some farm processing. And how can this be economical for bluefin tuna?  A 900 lb. fish goes for $50,000. Soon to be extinct from the Mediterranean, if not elsewhere. 

I do like the popular idea that aquaculture is fast tracking animal domestication for fish.