Climate Progress: An insider's view of climate science, politics, and solutions

Climate de-crocker Peter Sinclair directs us to this video from one of the greatest science writers of the 20th century:

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This guest post by Miloslav Nic was first published on Skeptical Science.

This is a post about my website Zvon.org where I’ve created a resource for the IPCC 4th Assessment Report (AR4). I’ve created a searchable database of almost every peer-reviewed paper referenced in the AR4, with links to each paper’s abstract and lists of all the authors. This provides a powerful tool that lets you search the AR4 by author, subject, title and journal.

I used to be an organic chemist in the last millennium who reached a tipping point in 2000 and was irreversibly transformed to a computer specialist. The primary forcing behind my change was the foundation of site Zvon.org which became quite well known among XML programmers.

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Here is an update of my review of the best papers on climate science in the past year.  If you want a broader overview of the literature in the past few years, focusing specifically on how unrestricted emissions of greenhouse gas emissions are projected to impact the United States, try “An introduction to global warming impacts: Hell and High Water.”

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According to the IPCC 4th Assessment Report (2007):
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A strong, credible body of scientific evidence shows that climate change is occurring, is caused largely by human activities, and poses significant risks for a broad range of human and natural systems….

Some scientific conclusions or theories have been so thoroughly examined and tested, and supported by so many independent observations and results, that their likelihood of subsequently being found to be wrong is vanishingly small. Such conclusions and theories are then regarded as settled facts. This is the case for the conclusions that the Earth system is warming and that much of this warming is very likely due to human activities.

The National Academy released three reports today on “America’s Climate Choices.”

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Progressives should know the most commonly used arguments by the disinformers and doubters — and how to answer them.

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This week marks the one-year anniversary of what the anti-science crowd successfully labeled ‘Climategate’.  The media will be doing countless retrospectives, most of which will be wasted ink, like the Guardian’s piece — focusing on climate scientists at the expense of climate science, which is precisely the kind of miscoverage that has been going on for the whole year!

I’ll save that my media critiques for Part 2, since I think that Climategate’s biggest impact was probably on the media, continuing their downward trend of focusing on style over substance, of missing the story of the century, if not the millennia.

The last year or so has seen more scientific papers and presentations that raise the genuine prospect of catastrophe (if we stay on our current emissions path) that I can recall seeing in any other year.

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Researchers often look at ice age as a way to estimate ice thickness. Older ice tends to be thicker than younger, one- or two-year-old ice.

The death spiral of Arctic sea ice continued this year, according to both observations and modeling.  The figure above comes from the National Snow and Ice Data Center.  In September, NSIDC’s director Mark Serreze said, “The volume of ice left in the Arctic likely reached the lowest ever level this month” and “I stand by my previous statements that the Arctic summer sea ice cover is in a death spiral. It’s not going to recover.”

Also in September, a first-of-its-kind analysis by an international team of 18 top scientists found “less ice covers the Arctic today than at any time in recent geologic history” and this ice loss is “unexplainable by any of the known natural variabilities.”

In November, Rear Admiral David Titley, the Oceanographer of the Navy and the Director of Navy’s Task Force Climate Change, testified that “the volume of ice as of last September has never been lower” — and that it is headed to zero in the summer.  You can read his testimony here.

Peter Sinclair has an excerpt of his testimony in an excellent video that shows just how wrong the discredited disinformers from WattsUpWithThat were in their sea ice projections this year:

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This is an excerpt from Skeptical Science by John Cook about the inimitable Professor Richard Alley, who was grilled last month by Dana “dinosaur flatulence” Rohrabacher (R-CA).  Alley was asked to explain in 15 seconds why climate has changed in the past and how we know humans are causing it now when they didn’t back then.

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Changes in clouds will amplify the warming of the planet due to human activities, according to a breakthrough study by a Texas A&M University researcher.

Andrew Dessler, a professor in the Department of Atmospheric Sciences, says that warming due to increases in greenhouse gases will cause clouds to trap more heat, which will lead to additional warming. This process is known as the “cloud feedback” and is predicted to be responsible for a significant portion of the warming over the next century….

“I think we can be pretty confident that temperatures will rise by several degrees Celsius over the next century if we continue our present trajectory of greenhouse gas emissions.”

A major new study in Science, “A Determination of the Cloud Feedback from Climate Variations over the Past Decade,” (subs. req’d) uses observations to answer what is probably the most important uncertainty in the climate models:  What is the feedback from clouds?

Now we can be confident the feedback is likely positive, and exceedingly unlikely to be negative enough to counter the many other positive, amplifying feedbacks.  In short, as Dessler says, “This work suggests that climate models are doing a pretty decent job simulating how clouds respond to changing climates.”  Recent studies have come to a similar conclusion — see Journal of Climate: New cloud feedback results “provide support for the high end of current estimates of global climate sensitivity.”

Because this is such an important issue — and because this study should be the final nail in the coffin of the central denier myth that the climate has a low sensitivity to CO2 — this post includes two videos explaining the study, an exclusive comment on the study by one of the leading experts on the cloud feedback (NCAR’s Kevin Trenberth), and Dessler’s debunking of the laughable conspiracy-laden response by a discredited disinformer (Roy Spencer).

Perhaps the most important point about the study is that it is the first of its kind based on actual observation, as the Texas A&M news release quoted above explains:

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An unprecedented combination of heat plus decades of drought could be in store for the Southwest sometime this century, suggests new research from a University of Arizona-led team….

“The bottom line is, we could have a Medieval-style drought with even warmer temperatures,” [lead author Connie] Woodhouse said.

In 2007, Science (subs. req’d) published research that “predicted a permanent drought by 2050 throughout the Southwest” — levels of aridity comparable to the 1930s Dust Bowl would stretch from Kansas to California.

In October, a National Center for Atmospheric Research (NCAR) study warned, “The United States and many other heavily populated countries face a growing threat of severe and prolonged drought in coming decades … possibly reaching a scale in some regions by the end of the century that has rarely, if ever, been observed in modern times.”

UPDATE:  A new Environmental Research Letters article, “Characterizing changes in drought risk for the United States from climate change,” comes to a similar conclusion as the NCAR study, “Drought frequencies and uncertainties in their projection tend to increase considerably over time and show a strong worsening trend along higher greenhouse gas emissions scenarios, suggesting substantial benefits for greenhouse gas emissions reductions.”  See especially Figure 4C.

Now a new Proceedings of the National Academy of Sciences study, “A 1,200-year perspective of 21st century drought in southwestern North America” looks at the paleoclimate record to see the kind of drought the southwest — and other regions — might experience.  It concludes:

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“Warm waters carried by the Antarctic Circumpolar Current are brushing the ice front in the western part of the continent, in the area of the Bellingshausen Sea.” [Click to enlarge.]

Antarctica is disintegrating much faster than almost anybody imagined — see “Nothing in the natural world is lost at an accelerating exponential rate like this glacier.” In 2001, the IPCC “consensus” said neither Greenland nor Antarctica would lose significant mass by 2100. They both already are.  As Penn State climatologist Richard Alley said in March 2006, the ice sheets appear to be shrinking “100 years ahead of schedule.”

A presentation Monday at the fall meeting of the American Geophysical Union sheds some light on the underlying cause of this rapid melt — the ice is being attacked from the bottom.  Discovery News has the story:

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Last week Nature published a study, “Greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence” (subs. req’d).  The journal had a pretty sensational cover, with a polar bear and the compelling headline, “Staying Alive:  Cut greenhouse-gas emissions now we can still save the polar bear.”

If you missed Nature, you probably saw the headlines:

• Arctic icecap safe from runaway melting: study (AFP)
• Polar Bears: On Thin Ice? Extinction Can Be Averted, Scientists Say (NSF press release)
  

I really wish any of that were realistic, not so much because the polar bear is a critical linchpin species, but because the loss of Arctic ice in the summer may well trigger even more rapid warming (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“ and below).  But in fact a much more reasonable AFP headline would be “Arctic ice cap on verge of runaway melting:  study.”  The NSF release should read, “Polar bear extinction now likely.”

I understand that journalists typically don’t read studies closely, but Nature ought to know better.    Perhaps, as we will see, it is just a matter of climate scientists of being utterly divorced from the reality of our energy and political systems.   Still, in reading the study and its supplementary information, I am puzzled why Nature published the article as written and especially why it chose to sensationalize it on the cover.

Let’s set aside, for now, the fact that the study focuses on sea ice area, not volume.  This is key figure in the paper:

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