In a new GRL paper, Svensmark et al., claim that liquid water content in low clouds is reduced after Forbush decreases (FD), and for the most influential FD events, the liquid water content in the oceanic atmosphere can diminish by as much as 7%. In particular, they argue that there is a substantial decline in liquid water clouds, apparently tracking a declining flux of galactic cosmic rays (GCR), reaching a minimum days after the drop in GCR levels. The implication would be that GCR can affect climate through modulating the low-level cloudiness. The analysis is based on various remote sensing products.
Climate Science
Friday round-up
Two items of interest this week. First, there is an atrocious paper that has just been published in JGR by McLean, de Freitas and Carter that is doing the rounds of the denialosphere. These authors make the completely unsurprising point that that there is a correlation between ENSO indices and global mean temperature – something that has been well known for decades – and then go on to claim that that all trends are explained by this correlation as well. This is somewhat surprising since their method of analysis (which involves taking the first derivative of any changes) eliminates the influence of any trends in the correlation. Tamino has an excellent demonstration of the fatuity of the statements in their hyped press-release and Michael Tobis deconstructs the details. For reference, we showed last year that the long term trends are still basically the same after you account for ENSO. Nevermore let it be said that you can’t get any old rubbish published in a peer-reviewed journal!
Second (and much more interestingly) there is an open call for anyone interested to contribute to setting the agenda for Earth System Science for the next couple of decades at the Visioning Earth Science website of the International Council for Science (ICS). This is one of the umbrella organisations that runs a network of committees and programs that prioritise research directions and international programs and they are looking for ideas. Let them know what your priorities are.
Sea ice minimum forecasts
One of the interesting things about being a scientist is seeing how unexpected observations can galvanize the community into looking at a problem in a different way than before. A good example of this is the unexpectedly low Arctic sea ice minimum in 2007 and the near-repeat in 2008. What was unexpected was not the long term decline of summer ice (this has long been a robust prediction), but the size of 2007 and 2008 decreases which were much larger than any model had hinted at. This model-data mismatch raises a number of obvious questions – were the data reliable? are the models missing some key physics? is the comparison being done appropriately? – and some less obvious ones – to what extent is the summer sea ice minimum even predictable? what is the role of pre-conditioning from the previous year vs. the stochastic nature of the weather patterns in any particular summer?
The concentration of polar expertise on the last couple of questions has increased enormously in the last couple of years, and the summer minimum of 2009 will be a good test of some of the ideas that are being discussed. The point is that whether 2009 is or is not a record-setting or near-record setting minimum, the science behind what happens is going to be a lot more interesting than the September headline.
Warming, interrupted: Much ado about natural variability
A guest commentary by Kyle Swanson – University of Wisconsin-Milwaukee
I am quite humbled by the interest that has been generated by our paper “Has the climate recently shifted?” (Swanson and Tsonis, 2009), and would like the thank the RealClimate editors for the opportunity to give my perspective on this piece.
Before delving into the paper itself, a few words about the place of our work in the global warming “debate” are in order. A quote from the early 20th century Viennese polymath Egon Friedell (which I ran across in the wonderful book Cultural Amnesia by Clive James) captures the situation better than any words I could ever weave;
Electricity and magnetism are those forces of nature by which people who know nothing about electricity and magnetism can explain everything.
Substitute the words “modes of natural climate variability” for “electricity and magnetism,” and well…, hopefully the point is made.
[Read more…] about Warming, interrupted: Much ado about natural variability
Two degrees
The countries of the G8 today approved a target of 2° C rise in global average temperature above the natural, preanthropogenic climate, that they resolve should be avoided. The Europeans have been pushing for 2 degrees as a target maximum temperature for several years, but this is something of a development for the Americans. We posted recently on two new papers about what it would take to limit global average warming, finding that it would require fairly strong change in trajectory. About 2° C as a target, we wrote,
… even a “moderate” warming of 2°C stands a strong chance of provoking drought and storm responses that could challenge civilized society, leading potentially to the conflict and suffering that go with failed states and mass migrations. Global warming of 2°C would leave the Earth warmer than it has been in millions of years, a disruption of climate conditions that have been stable for longer than the history of human agriculture. Given the drought that already afflicts Australia, the crumbling of the sea ice in the Arctic, and the increasing storm damage after only 0.8°C of warming so far, a target of 2°C seems almost cavalier.
Nevertheless, we view today’s development as a constructive step.
‘Unscientific America’: A Review
Author Chris Mooney (of “Storm World” fame) and fellow “Intersection” blogger, scientist, and writer Sheril Kirshenbaum have written an extraordinary, if rather sobering book entitled ‘Unscientific America’. What I found most refreshing about the book is that it not only isolates the history behind, and source of, the problem in question—the pervasiveness and dangerousness of scientific illiteracy in modern society–but it offers viable solutions. This book is a must read for anybody who cares about science, and the growing disconnect between the scientific and popular cultures (the problem of the so-called “Two Cultures” first discussed by C.P. Snow).
‘Unscientific America’ explores how we’ve come to the point we’re now at, examining the historical factors behind the diminishing prominence of science and scientists in the popular culture of the U.S. since its heyday in the years following WW II. The authors uncover more than enough blame to go around. They find fault with the media, both in how it portrays science and scientists (e.g. the icon of the ‘mad scientist’), and in the decreasing news coverage devoted to issues involving science and technology. They find fault in the way policy makers often abuse science (cherry-picking those particular scientific findings which suit their agenda), and in the behavior of corporate special interests who, in areas such as our own area of ‘climate change’, have often deliberately manufactured false controversy and confusion to dissuade the public from demanding action be taken. At this point, the scientists among you might begin to feel absolved of any responsibility for the problem. Don’t–Mooney and Kirshenbaum won’t allow us to escape blame, and with good reason. As they point out, we ‘eat our own’, when it comes to colleagues engaged in public outreach and science popularization. Case in point: Carl Sagan–a hero to many of us who value science outreach. One of the darker episodes in modern U.S. science history was the blocking by Sagan’s fellow scientists of his entry into the U.S. National Academy of Sciences. Evidently, a majority of his colleagues resented his having become a household name–something they presumably considered unbecoming for a scientist. What sort of message does it send when the most effective science communicator in modern history was shunned by his colleagues for his efforts? Certainly not a good one. This is just one example, and there are many others–it is not surprising that so few scientists to choose to pursue the path of outreach and public education. The reward systems in academia and the scientific world typically do not favor scientists who choose to expend considerable time and effort engaging in public discourse. And here of course, it is as much that system, as the scientists themselves, which is to blame.
Science at the bleating edge
Many of you will remember our pioneering discussion of the Sheep-albedo hypothesis, where we suggested that increasing numbers of sheep would cause a cooling climate because of their impact on the ground reflectivity. Well, new observations have now added significantly more complexity to this seemingly understood situation. It has just been reported that as well as the original sheep-albedo effect, there is now evidence of a second sheep-albedo effect (smaller sheep as the world warms). That would be a amplifying effect in general, but the actual population of sheep concerned come in many colours, so the overall affect is uncertain. (There is even speculation about a third effect (the sheep lifetime albedo impact), which could go either way depending the Lamb Marketing Board advertising campaign).
Yet more evidence that the science is very woolly.
*Title taken from a comment from glen
Science at the bleeding edge
The vast majority of mainstream media items about science are related to new hot-off-the-press studies, often in high profile journals, that report a new breakthrough, or that purportedly overturn previous ideas. However, while these are exciting news items, this preponderance of coverage given to these state-of-the-art studies compared to assessments such as from the National Academies, can give a misleading impression about the state of a scientific knowledge. The more mature and solid a field, the less controversy there is, and thus the fewer news stories. Ironically, this means the public is told the least about the most solid aspects of science.
One effect of this tendency is that quite often news stories are focused on claims that turn out to be wrong, or if not actually wrong, heavily reduced in importance by the time the dust settles. This is not deliberate, but merely how science works at the frontier. People push measurements to the limit of their accuracy (and sometimes beyond) and theories are used slightly out of their domain of applicability. In recognition of that, Richard Feynman had a useful rule of thumb that the last data point on any graph should be discounted because, if it had been easy to obtain, there would have been another one further along.
More bubkes
) (
) Roger Pielke Sr. has raised very strong allegations against RealClimate in a recent blog post. Since they come from a scientific colleague, we consider it worthwhile responding directly.
The statement Pielke considers “misinformation” is a single sentence from a recent posting:
Some aspects of climate change are progressing faster than was expected a few years ago – such as rising sea levels, the increase of heat stored in the ocean and the shrinking Arctic sea ice.
First of all, we are surprised that Pielke levelled such strong allegations against RealClimate, since the statement above merely summarises some key findings of the Synthesis Report of the Copenhagen Climate Congress, which we discussed last month. This is a peer-reviewed document authored by 12 leading scientists and “based on the 16 plenary talks given at the Congress as well as input of over 80 chairs and co-chairs of the 58 parallel sessions held at the Congress.” If Pielke disagrees with the findings of these scientists, you’d have thought he’d take it up with them rather than aiming shrill accusations at us. But in any case let us look at the three items of alleged misinformation:
Bubkes
) () Some parts of the blogosphere, headed up by CEI (“CO2: They call it pollution, we call it life!“), are all a-twitter over an apparently “suppressed” document that supposedly undermines the EPA Endangerment finding about human emissions of carbon dioxide and a basket of other greenhouse gases. Well a draft of this “suppressed” document has been released and we can now all read this allegedly devastating critique of the EPA science. Let’s take a look…