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New public opinion poll on global warming

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There is a new Zogby poll on public attitudes in the US towards global warming and the potential connection between severe weather events and climate change.

Unsurprisingly to us (but maybe not to others), most of the US public feel that global warming is happening (around 70%), and roughly the same amount of people report being more or much more convinced of this over the last two years.

More interestingly, the pollsters asked whether people believed that global warming was having an effect on intense hurricanes, droughts, heat waves and the like. Again, roughly 70% of people thought that global warming was having either some effect or a major effect on these weather extremes (note that the question was not phrased to ask whether any specific event was thought likely to have been caused by global warming (which was probably a good choice)).

This begs the question whether people’s experience of severe weather has convinced them that climate change is occuring. Televangelist Pat Robertson, for instance, said very recently that it was the latest heat wave that finally convinced him. I think this is likely to be true for most of the public who are not following the issue very carefully (which is most of them of course!). The most significant single event in this context was probably Katrina, regardless of how much climate change can or can’t be associated with Katrina the Hurricane (let alone Katrina the Disaster!).

I would guess that this is likely to be a very common way for public opinion to be formed across a whole number of issues. That is, when a dominant theme is very prevalent across a wide spectra of media, everyday occurrences or new information are often processed with that in mind, and given our extraordinary ability to see patterns in noisy data, we often end up associating the theme with our own experiences. Other examples surely abound in medical or political contexts.

Given that pattern, it is probably overly optimistic to expect scientists, who continually stress that single weather events can’t in general be attributed to climate change but that changes in statistics might be, to have much success in conveying these finer points to the public directly. Instead, their skills are probably best used in clarifying these points to those (e.g. journalists, policy-makers) that set the dominant themes in the first place.

Fact, Fiction, and Friction in the Hurricane Debate

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Michael Mann and Gavin Schmidt

Judith Curry and colleagues have an interesting (and possibly provocative) article, “Mixing Politics and Science in Testing the Hypothesis That Greenhouse Warming Is Causing a Global Increase in Hurricane Intensity” in the latest issue of the Bulletin of the American Meteorological Society (BAMS). The article provides a solid review of the recent developments in the science focusing on potential climate change impacts on tropical cyclones. However, the article is more novel in its approach than the typical scientific review article. For instance, it attempts to deal with the issue of how one should test hypotheses that reflect a complex causal chain of individual hypotheses. This is of course relevant to investigations of climate change influences on tropical cyclone activity, where one is attempting to connect a phenomenon (climate change) that is global in spatial scale and multidecadal in timescale, to a phenomena that is intrinsically “mesoscale” (that is, spans at most hundreds of kilometers) in space and lasts only a few days.

More unusually, the article also takes an introspective look at the role of scientists in communicating societally-relevant science to the public, and provides a critical review of how the science dealing with climate change impacts on tropical cyclones and hurricanes has been reported in the media, and how that reporting has occasionally deepened the polarisation on the issue. In doing so, the article revisits some of the “false objectivity” problems we have talked about before (see here and here). They also assess fairly the quality of the arguments that have been made in response to the Emanuel (2005) and Webster et al (2005) papers in the hope of focussing discussion on the more valid points, rather than some of the more fallacious arguments. The article is unapologetic in advancing their particular point of view, and while we generally share it, we imagine that some readers may disagree. We hope, as we suspect the authors do as well, that it will in any case generate a productive discussion.

Ocean heat content: latest numbers

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Net ocean heat content changes are very closely tied to the net radiative imbalance of the planet since the ocean component of the climate system has by far the biggest heat capacity. Thus we have often made the point that diagnosing this imbalance through measurements of temperature in the ocean is a key metric in evaluating the response of the system to changes in CO2 and the other radiative forcings (see here).
In a paper I co-authored last year (Hansen et al, 2005), we compared model results with the trends over the 1993 to 2003 period and showed that they matched quite well (here). Given their importance in evaluating climate models, new reports on the ocean heat content numbers are anticipated quite closely.

Recently, a new preprint with the latest observations (2003 to 2005) has appeared (Lyman et al, hat tip to Climate Science) which shows a decrease in the ocean heat content over those two years, decreasing the magnitude of the long-term trend that had been shown from 1993 to 2003 in previous work (Willis et al, 2004) – from 0.6 W/m2 to about 0.33 W/m2. This has generated a lot of commentary in some circles, but in many cases the full context has not been appreciated.
[Read more…] about Ocean heat content: latest numbers

Short and simple arguments for why climate can be predicted

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Sometimes, I encounter arguments suggesting that since we cannot predict the weather beyond a couple of weeks, then it must be impossible to predict the climate in 100 years. Such statements tend to present themselves as a kind of revelation, often in social settings and parties after I have revealed for some of the guests that I’m a climatologist (if I say I work for the Meteorological Institute, I almost always get the question “so, what’s the weather going to be like tomorrow?”). Such occasions also tend to be times when I’m not too inclined to indulge in deep scientific or technical explanations. Or when talking to a journalist who wants an easy answer. In those cases I try to provide a short and simple, but convincing, explanation that is easy for most people to understand why climate can be predicted despite the chaotic nature of the weather (a more theoretical discussion is provided in the earlier post Chaos and Climate). One approach is to try to relate the topic to something with which they are familiar, such as to point to empirical observations which most accept (I suppose with hindsight it could be similar to the researchers in the early 20th century trying to convince that nuclear reactions were possible – just look at the Sun, and there is the proof! Or before that, the debate about whether atoms were real or not – just look at the blue sky, and you look at the proof…). I like to emphasised the words ‘weather‘ and ‘climate‘ above, because they mean different things.

[Read more…] about Short and simple arguments for why climate can be predicted

The missing repertoire

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There was a small flurry of activity last week when the report “Warm words: How are we telling the climate story and how can we tell it better?” was released by the IPPR (a UK based left-leaning think tank). Most of the attention was focussed on their attention-seeking description of the more breathless media depictions of climate change as ‘climate porn’. However, the report was actually more interesting than just that, but possibly in ways that the authors didn’t intend.

[Read more…] about The missing repertoire

Amazonian drought

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Translations: (Slovenčina)

There has been a flurry of recent commentary concerning Amazon drought – some of it good, some of it not so good. The good stuff has revolved around a recently-completed interesting field experiment that was run out of the Woods Hole Research Center (not to be confused with the Woods Hole Oceanographic Institution), where they have been examining rainforest responses to drought – basically by using a very large rainproof tent to divert precipitation at ground level (the trees don’t get covered up). As one might expect, a rainforest without rain does not do well! But exactly what happens when and how the biosphere responds are poorly understood. This 6 year long field experiment may provide a lot of good new data on plant strategies for dealing with drought which will be used to improve the models and our understanding of the system.

The not-so-good part comes when this experiment is linked too directly to the ongoing drought in the southern Amazon. In the experiment, older tree mortality increased markedly after the third year of no rain at all (with around 1 in 10 trees dying). Since parts of the Amazon are now entering a second year of drought (possibly related to a persistent northward excursion of the ITCZ), the assumption in the Independent story (with the headline ‘One year to save the Amazon’) was that trees will start dying forest-wide next year should the drought continue. [Read more…] about Amazonian drought

Climate Feedbacks

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Guest Commentary by Brian Soden (RSMAS, Miami)

Current model estimates of the climate sensitivity, defined as the equilibrated change in global-mean surface temperature resulting from a doubling of CO2, range from 2.6 to 4.1 K, consistent with observational constraints (see previous article). This range in climate sensitivity is attributable to differences in the strength of ‘radiative feedbacks’ between models and is one of the reasons why projections of future climate change are less certain than policy makers would like. [Read more…] about Climate Feedbacks

Peter Doran and how misleading talking points propagate

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Peter Doran, the lead author on a oft-cited, but less-often read, Nature study on Antarctic climate in 2002 had an Op-Ed in the NY Times today decrying the misuse of his team’s results in the on-going climate science ‘debate’. As we discussed a while back (Antarctic cooling, global warming?), there is a lot of interesting stuff going on in Antarctica: the complexities of different forcings (ozone in particular), the importance of dynamical as well as radiative processes, and the difficulties of dealing with very inhomogeneous and insufficiently long data series. But like so many results in this field, it has become a politicized ‘talking point’, shorn of its context, that is mis-quoted and mis-used by many who should (and often do) know better. Doran complained about the media coverage of his paper at the time, and with the passage of time, the distortion has predictably increased. Give it another few years, maybe we’ll be having congressional hearings about it…

Disinformation? You want it, IREA’s got it

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RealClimate received a copy of a letter from the General Manager of the Intermountain Rural Electric Association (IREA, an energy cooperative in Colorado), Stanley R. Lewandowski (Jr), to other utilities (G&T’s in the jargon) in the US discussing fundraising and tactics for a new disinformation campaign on climate change (see Seth Borenstein’s piece yesterday).

This is enlightening on a number of levels. Firstly, though we knew that this stuff goes on, it’s rare that we get such a close look at how it happens. Secondly, who is to be the lead on this new campaign? None other than our old friend Patrick Michaels. Additionally, it is useful to see the reasons why some utilties are fighting against the idea of climate change set out more clearly than in their more carefully manicured press briefings. It might actually help people engage on the substance of their concerns rather than simply arguing about the science – which, as we are by now well aware, – is simply a path to gridlock.

We’ll highlight some of the best bits, and discuss what this all might imply below. [Read more…] about Disinformation? You want it, IREA’s got it

The not-just-in-Copenhagen consensus

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Anyone who spends any time mixing with climate scientists or really looking at the literature knows that the scientific consensus on the reality of human-related climate change is almost universal. Thus it is not at all surprising that methods designed to assess this consensus objectively – such as that undertaken by Oreskes in 2004 and recently re-asserted in the LA Times (non-subscription version) come up with very conclusive results. Similar studies could be done by looking at abstracts at big meetings (AGU, EGU etc.) or simply by talking to us. One could of course argue about what this means, but the existence of this consensus is not really up for debate. That doesn’t stop some people from trying of course, but these attempts have been rather embarrassing at best.

However, that didn’t prevent the latest incoherent and highly misleading press release from the Senate EPW committee being issued to support the effort. I was recently in conversation with a journalist, who told me that she’d asked the ex-talk-radio author of these EPW releases, Mark Morano, what exactly they were suppposed to achieve. Morano replied that it was to ‘get their message out’. When asked what that message was, no clear answer was forthcoming. That politicians indulge in politics is not surprising, but these releases are really scraping along the bottom. The only consolation is that they are being completely ignored by the media. Long may that consensus remain!