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Putting the recent Antarctic snowmelt minimum into context

Filed under: — eric @ 27 October 2009

Guest Commentary by Andrew Monaghan and Marco Tedesco

Our study published in mid October in Geophysical Research Letters (Tedesco and Monaghan, 2009) documents record minimum snowmelt for Antarctica during austral summer 2008-2009 and lower-than-normal melt for several recent years, based on a 30-year satellite microwave record. Numerous blogs have cited the results as a challenge to previous studies reporting Antarctic warming, while also steadfastly ignoring other studies with similar results (e.g. Barrett et al., 2009). They have overlooked that these studies show that Antarctic warming has occurred mostly in winter and spring, whereas melting of course occurs in summer. And they oversimplify the causality and hence confuse our prediction for the future. We found that the same mechanism that has primarily caused low snowmelt in recent years will likely change in a manner that will enhance snowmelt in forthcoming decades. A brief summary follows. More »

350

Filed under: — gavin @ 27 October 2009

I was quoted by Andrew Revkin in the New York Times on Sunday in a piece about the 350.org International Day of Climate Action (involving events in 181 countries). The relevant bit is:

Gavin A. Schmidt, a climate scientist who works with Dr. Hansen and manages a popular blog on climate science, realclimate.org, said those promoting 350 or debating the number might be missing the point.
“The situation is analogous to people trying to embark on a cross-country road trip to California but they’ve started off heading to Maine instead,” Dr. Schmidt said. “But instead of working out ways to turn around, they have decided to argue about where they are going to park when they get to L.A.”
“If you ask a scientist how much more CO2 do you think we should add to the atmosphere, the answer is going to be none.”

I’ve been told that some readers may have misinterpreted the quote as a criticism of the 350.org campaign itself. This was not the intent and in fact my metaphor wouldn’t have made sense in that context at all. Instead, it was a criticism of people who are expending effort arguing about whether 350 is precisely the right number for a long term target, or whether it should be somewhat higher or lower. Since we aren’t currently headed anywhere near 350 ppmv (in fact we are at 388 ppmv CO2 and increasing by about 2 ppmv/yr), we need to urgently think of ways the situation can turn around. Tapping into the creativity and enthusiasm shown by the 350.org campaigners will certainly be part of that process.

We discussed some of the thinking behind this ‘Target CO2‘ when Jim Hansen and colleagues’ paper first came out, where I think we made it clear that picking a specific CO2 target to avoid ‘dangerous’ climate change is an inexact science at best. The comments by Robert Brulle and Ray Pierrehumbert at DotEarth and James Hrynyshyn also highlight some of that complexity. And I think the suggestions by ‘Paulina‘ for how a tweaked article might have been clearer are very apropos.

However, as the final line in my NYT quote should make clear, personally I think the scientific case not increasing CO2 any further is very strong. Since the planet has not caught up with current levels of concentrations emissions (and thus will continue to change), picking an ultimate target that is less than today’s level is therefore wise. Of course, how we get there is much trickier than knowing where it is we should be going, but having a map of the destination is useful. As we discussed in the ‘trillionth ton‘ posting a couple of months back, how we get there also makes a difference.

In my original email to Andy Revkin, I had actually appended a line:

If you ask a scientist how much more CO2 do you think we should add to the atmosphere, the answer is going to be none.

All the rest is economics.

(and technology, and sociology, and psychology and politics etc.) but the point is that working out how we get there from here is the real challenge and the more people who are aware and involved in developing those solutions the better.

Climate Cover-Up: A (Brief) Review

Filed under: — mike @ 20 October 2009

We often allude to the industry-funded attacks against climate change science, and the dubious cast of characters involved, here at RealClimate. In recent years, for example, we’ve commented on disinformation efforts by industry front groups such as the “Competitive Enterprise Institute, the Cato Institute, the Fraser Institute, and a personal favorite, The Heartland Institute, and by industry-friendly institutions such as the Wall Street Journal editorial board, and other media outlets that assist in the manufacture and distribution of climate change disinformation.

When it comes to the climate change disinformation campaign, we have chosen to focus on the intellectually bankrupt nature of the scientific arguments, rather than the political motivations and the sometimes intriguing money trail. We leave it to others, including organizations such as SourceWatch.org, the sleuths at DeSmogBlog, authors such as Ross Gelbspan (author of The Heat is On, and The Boiling Point), and edited works such as Rescuing Science from Politics to deal with such issues.

One problem with books on this topic is that they quickly grow out of date. Just over the past few years, there have been many significant events in the ‘climate wars’ as we have reported on this site. Fortunately, there is a book out now by our friends at DeSmogBlog (co-founder James Hoggan, and regular contributor Richard Littlemore) entitled Climate Cover Up: The Crusade to Deny Global Warming that discusses the details of the contrarian attacks on climate science up through the present, and in painstaking detail. They have done their research, and have fully documented their findings, summarized by the publisher thusly:

Talk of global warming is nearly inescapable these days — but there are some who believe the concept of climate change is an elaborate hoax. Despite the input of the world’s leading climate scientists, the urgings of politicians, and the outcry of many grassroots activists, many Americans continue to ignore the warning signs of severe climate shifts. How did this happen? Climate Cover-up seeks to answer this question, describing the pollsters and public faces who have crafted careful language to refute the findings of environmental scientists. Exploring the PR techniques, phony “think tanks,” and funding used to pervert scientific fact, this book serves as a wake-up call to those who still wish to deny the inconvenient truth.

There are interesting new details about the Revelle/Singer/Lancaster affair and other tidbits that were new to me, and will likely to be new to others who been following the history of climate change contrarianism. Ross Gelbspan who has set the standard for investigative reporting
when it comes to the climate change denial campaign, had this to say about the book:

absolutely superb-one of the best dissections of the climate information war I
have ever seen. This is one terrific piece of work!

There is an important story behind the climate change denial effort that goes well beyond the scientific issues at hand. Its not our mission at RealClimate to tell that story, but there are others who are doing it, and doing it well. Hoggan and Littlemore are clearly among them. Read this book, and equally important, make sure that others who need to do as well.

Why Levitt and Dubner like geo-engineering and why they are wrong

Filed under: — gavin @ 18 October 2009

Many commentators have already pointed out dozens of misquotes, misrepresentations and mistakes in the ‘Global Cooling’ chapter of the new book SuperFreakonomics by Ste[ph|v]ens Levitt and Dubner (see Joe Romm (parts I, II, III, IV, Stoat, Deltoid, UCS and Paul Krugman for details. Michael Tobis has a good piece on the difference between adaptation and geo-engineering). Unfortunately, Amazon has now turned off the ’search inside’ function for this book, but you can read the relevant chapter for yourself here (via Brad DeLong). However, instead of simply listing errors already found by others, I’ll focus on why this chapter was possibly written in the first place. (For some background on geo-engineering, read our previous pieces: Climate Change methadone? and Geo-engineering in vogue, Also the Atlantic Monthly “Re-Engineering the Earth” article had a lot of quotes from our own Raypierre).
More »

Why the continued interest?

Filed under: — rasmus @ 9 October 2009

I believe the idea that galactic cosmic rays (GCR) play a role for the present global warming is unlikely to fade soon, despite a growing number of scientific arguments that normally would falsify a hypothesis and lay it dead (see links here and here). Despite all the arguments against the role of GCR, there was a solicited talk about ‘cosmoclimatology’ at the European Meteorological Society’s (EMS) annual meeting in Toulouse. Henrik Svensmark is further invited by the Norwegian Academy of Science and Letters (NASL) to provide an introduction to their seminar on climate. So why is the GCR-hypothesis still perceived as an interesting explanation?

More »