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Hansen’s 1988 projections

At Jim Hansen’s now famous congressional testimony given in the hot summer of 1988, he showed GISS model projections of continued global warming assuming further increases in human produced greenhouse gases. This was one of the earliest transient climate model experiments and so rightly gets a fair bit of attention when the reliability of model projections are discussed. There have however been an awful lot of mis-statements over the years – some based on pure dishonesty, some based on simple confusion. Hansen himself (and, for full disclosure, my boss), revisited those simulations in a paper last year, where he showed a rather impressive match between the recently observed data and the model projections. But how impressive is this really? and what can be concluded from the subsequent years of observations?
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Fun with correlations!

Filed under: — gavin @ 9 May 2007 - (Türkçe)

We are forever being bombarded with apparently incredible correlations of various solar indices and climate. A number of them came up in the excoriable TGGWS mockumentary last month where they were mysteriously ‘improved’ in a number of underhand ways. But even without those improvements (which variously involved changing the axes, drawing in non-existent data, taking out data that would contradict the point etc.), the as-published correlations were superficially quite impressive. Why then are we not impressed?

To give you an idea, I’m going to go through the motions of constructing a new theory of political change using techniques that have been pioneered by a small subset of solar-climate researchers (references will of course be given). And to make it even more relevant, I’m going to take as my starting point research that Richard Lindzen has highlighted on his office door for many years:
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This Week

Filed under: — mike @ 4 May 2007 - (Türkçe)

There are a few minor items this week worthy of mention:

1. The CO2 rise. Who dunnit?

Here at RealClimate, we have been (naively, apparently) operating under the assumption that climate change contrarians had long ago moved on from the untenable position that humans are not even responsible for the observed increase in CO2 concentrations over the past two centuries. The dubious paper by Ernst Beck we commented on the other day indicates that there is indeed still a rear guard attack being waged. As if to drive the point home further, pundit Alexander Cockburn, known generally for his progressive views, has perplexingly disputed the existence of any link between CO2 emissions and rising CO2 concentrations in the atmosphere in a screed he penned this week for the online journal “Counterpunch” (also printed in The Nation). It’s hard to know where to start, since his piece is so over the top and gets just about everything so thoroughly wrong, it’s almost comical. So we’ll just hit the low points: (a) Cockburn claims that there is zero empirical evidence that anthropogenic production of CO2 is making any measurable contribution to the world’s present warming trend, despite the fact that not even such strident climate change contrarians as Pat Michaels dispute that there is a measurable influence of anthropogenic greenhouse gases on global temperature. Plus there’s all the empirical evidence of course (see the new IPCC report). (b) Going further, Cockburn brazenly opines that ‘it is impossible to assert that the increase in atmospheric CO2 stems from human burning of fossil fuels’ despite the fact that there is an isotopic smoking gun for this connection. He then (c) fails to understand that water vapor is a feedback not a forcing, and citing ‘expert’ Dr. Martin Hertzberg, quite remarkably states that ‘It is the warming of the earth that is causing the increase of carbon dioxide and not the reverse.’ Never mind that isotopic evidence proves otherwise. Upon what evidence does he base this assertion?

Since no anti-global warming op-ed these days is complete without it, Cockburn (d) resorts to the usual misrepresentation of lag/lead relationships between CO2 and temperatures during glacial/interglacial cycles as if they disprove the causal relationship between greenhouse gas concentrations and surface temperatures (see our most recent debunking of this favorite contrarian talking point here). Oh dear.

2. The other (Glenn) Beck–Even Worse!

CNN gave their resident shock-jock Glenn Beck a forum for spreading more disinformation on global warming in an hour-long segment entitled Exposed: The Climate of Fear (see also this discussion by “Media Matters”). We could pick apart his (rather thin) arguments, which constitute the usual cocktail of long debunked contrarian talking points. Suffice it to say, however, that the moment a rhetorician invokes Hitler, Nazi Germany, and Eugenics, it is the moment they are no longer worthy of being listened to (cf Godwin’s Law of usenet debates). We don’t seem to be alone in our opinion here. Beck’s performance earned him the dubious title of “worst person in the world” from analyst Keith Olbermann.

However, there was one amusing moment: Beck asked Christopher ‘Incorrect’ Horner what the key thing to google was that would show that Al Gore was wrong. Horner suggested the lag between CO2 and temperature in the ice cores. Of course, if you do Google that, the first hit is the RealClimate debunking of the issue. Thanks!

3. Nature’s new blog

Nature has started a new blog called “Climate Feedback”, which says of itself ‘Climate Feedback is a blog hosted by Nature Reports: Climate Change to facilitate lively and informative discussion on the science and wider implications of global warming. The blog aims to be an informal forum for debate and commentary on climate science in our journals and others, in the news, and in the world at large.’

We wish it well, remembering their welcome for RealClimate, though early reviews based on the first few posts are decidedly mixed.

Thin Soup and a Thin Story

Filed under: — david @ 2 May 2007 - (Türkçe) (Български)

A firm called planktos.com is getting a lot of airplay for their bid to create a carbon offset product based on fertilizing the ocean. In certain parts of the ocean, surface waters already contain most of the ingredients for a plankton bloom; all they lack is trace amounts of iron. For each 1 atom of iron added in such a place, phytoplankton take up 50,000 atoms of carbon. What could be better?
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Beck to the future

Filed under: — group @ 1 May 2007

Guest commentary from Georg Hoffmann

Our understanding of the natural carbon cycle has greatly improved since the times of Svante Arrhenius (1859-1927) and Guy Stewart Callendar (1898-1964). We know what the atmospheric background value of CO2 currently is (it passed 380ppm last year, about 100ppm over the pre-industrial level), we know the seasonal/diurnal cycle in different environments, we have been able to put reasonable constraints on terrestrial and marine sources and sinks, and finally we know the impact of fuel combustion both globally and locally in heavily polluted areas.
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