Saturday :: Jul 25, 2009

Climate Denial

by eriposte

Peter Sinclair has been doing a great job with his series of videos titled "Climate Denial: Crock of the Week" posted through his YouTube "channel". His videos are very helpful in explaining complex concepts to average people and more importantly debunking the mind-numbing stupidity that characterizes a portion of the climate change denial community.

Today, here is the latest installment from the site "Climate Realists"- a post that reproduced some dreck published in the U.K.'s Telegraph by Christopher Booker (this guy), titled "Global cooling hits Al Gore's home". Here's the first claim:

It was delightfully appropriate that, as large parts of Argentina were swept by severe blizzards last week, on a scale never experienced before, the city of Nashville, Tennessee, should have enjoyed the coolest July 21 in its history, breaking a record established in 1877. Appropriate, because Nashville is the home of Al Gore, the man who for 20 years has been predicting that we should all by now be in the grip of runaway global warming.

The use of cherry-picked weather patterns to apparently rebut claims of global climate change is perhaps the most predictable but also one of the most extraordinarily stupid tactics of the climate change denial community. (It's kinda like saying - lots of Americans in Texas vote Democratic, so Texas cannot be a "red" state and hoping that your readers are just complete morons who think this is a great argument.)

Anyway, one of Sinclair's "Climate Denial: Crock of the Week" videos is focused on this very topic: "It's Cold. So there's no climate change". Here it is:

Let's look at the additional nonsense in the Telegraph/"Climate Realists "post, which is many ways the most devious nonsense peddled by the climate change denialist crowd (emphasis mine):

In the past few years, Dr Hansen's temperature record has become ever more eccentric, often wildly at odds with the other three officially recognised data sources, all of which showed a dramatic drop in temperatures in 2007 leading to markedly cooler summers and two of the coldest and snowiest winters the world has known for decades. All this has equally made nonsense of the predictions of the computer models that the UN's Intergovernmental Panel on Climate Change relies on, which are programmed to assume that temperatures should soar in line with rising levels of greenhouse gases.

The notion that IPCC climate models merely assume that temperatures will keep going up as greenhouse gas concentrations keep rising is of course a lie. Anyone who has read the IPCC papers or for that matter any mainstream peer-reviewed scientific papers published by the climate change community knows that greenhouse gases are only considered one of various factors that can cause global climate change. It just so happens that the preponderance of data shows that the primary factor explaining the late 20th century rise in global average temperatures is a sharp increase in greenhouse gas concentrations, particularly CO2. The IPCC, and other papers, do in fact discuss the effects of various other factors, including solar activity, volcanic activity, aerosols, ozone, and natural atmospheric, land-based and oceanic variability and it is well known that some or many of these other factors could modulate the long-term, dominant forcing trend attributed to greenhouse gases. This chart is a good example to see this visually. One of Sinclair's videos addresses some of these factors in response the astonishingly fraudulent "documentary" that was produced a while ago - called "The Great Global Warming Swindle" (TGGWS). There is a website devoted to debunking TGGWS systematically, but Sinclair's short video is an excellent one. Take a look:

A final point on the claim of a "dramatic drop in temperatures in 2007...". Sinclair's first vidoe above addresses this in part, but there's a good post at Real Climate from a couple of weeks ago - "Warming, interrupted: Much ado about natural variability" by Kyle Swanson, who is a co-author of a recent paper discussing a "pause in warming". It is worth reading the post in full but here are some excerpts (emphasis mine):

...our paper is fundamentally about inter-decadal variability in the climate system and its role in the evolution of the 20th century climate trajectory, as well as in near-future climate change. The climate system has well known modes of variability, such as the El Niño/Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO), that are active on inter-annual time scales. We are interested in how this short time-scale (from the climate perspective!) variability impacts climate anomalies over multi-decadal time periods.

What we find is that when interannual modes of variability in the climate system have what I’ll refer to as an “episode,” shifts in the multi-decadal global mean temperature trend appear to occur. I’ll leave the details of these episodes to interested readers (here and here), as things get pretty technical. It’s sufficient to note that we have an objective criteria for what defines an episode; we aren’t just eyeballing curves. The climate system appears to have had three distinct “episodes” during the 20th century (during the 1910’s, 1940’s, and 1970’s), and all three marked shifts in the trend of the global mean temperature, along with changes in the qualitative character of ENSO variability. We have also found similar types of shifts in a number of model simulations (both forced and unforced) that were run in support of the IPCC AR4 report.

The contentious part of our paper is that the climate system appears to have had another “episode” around the turn of the 21st century, coinciding with the much discussed “halt” in global warming. Whether or not such a halt has really occurred is of course controversial (it appears quite marked in the HadCRUT3 data, less so in GISTEMP); only time will tell if it’s real. Regardless, it’s important to note that we are not talking about global cooling, just a pause in warming.

P.S. I will try to post additional episodes from Sinclair in the next couple of weeks. Tim Lambert's post: "Pielke Sr's new statistical technique" is also worth a read to understand the climate change denialist view of statistics.

eriposte :: 1:43 PM :: Comments (31) :: Digg It!