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Explaining climate change science & rebutting global warming misinformation
Scientific skepticism is healthy. Scientists should always challenge themselves to improve their understanding. Yet this isn't what happens with climate change denial. Skeptics vigorously criticise any evidence that supports man-made global warming and yet embrace any argument, op-ed, blog or study that refutes global warming. This website gets skeptical about global warming skepticism. Do their arguments have any scientific basis? What does the peer reviewed scientific literature say?
Posted on 13 February 2012 by John Cook
Since launching in December 2010, the English version of the Scientific Guide to Global Warming Skepticism has been downloaded 812,000 times and is being used by teacher associations, museums, websites, student groups and other organisations. The Guide has also been translated into 16 languages. The latest translation is Finnish. Many thanks to Ari Jokimäki, Kaj Luukko, Esko Pettay and Janne Tuukkanen for their contributions to the translation.
Note to other translators:
Posted on 13 February 2012 by John Hartz
Rob Painting's Global Sea Level Rise: Pothole To Speed Bump? and John Cook's Book review of Michael Mann's The Hockey Stick and the Climate Wars garnered the most comments this past week. The title of Michaels Misrepresents Nordhaus and Scientific Evidence in General by Alex C speaks for itself.
Toon of the Week
Posted on 13 February 2012 by Rob Honeycutt
Journalist Peter Hadfield has produced a new Youtube video regarding all the headlines that were splashed across the news circuits last week claiming that there's been "No Melt in 10 Years."
Peter's MO has become the simple act of "reading the actual research." In this video he applies this unique journalistic technique to Jacob et. al 2012, "Recent contributions of glaciers and ice caps to sea level rise" and gets us to the bottom of what the rest of the media manages to miss.
Posted on 12 February 2012 by Neven
This is a summary/re-write of a recent blog post on the Arctic Sea Ice blog.
We are entering the final stage of the freezing season in the Arctic. The sea ice has reached all shores, and where there aren't shores it reaches as far south as the winds and currents will permit. Or, at least it used to go like that.
Ice growth had been relatively slow in sea ice regions like the Barents Sea, Kara Sea and Greenland Sea (see this Cryosphere Today map to get an idea of where the regions are), but nothing (much) out of the ordinary. However, in the past two weeks a persistent weather pattern emerged that is bringing Siberian cold to almost all of Europe, but warm air and water to Novaya Zemlya, the large island that separates the Barentsz and Kara Seas.
The effect this has had can clearly be seen when comparing yesterday's sea ice concentration image with those of previous years on the same date:
image courtesy of the University of Bremen
Posted on 11 February 2012 by dana1981
The title of the post was a reference to the film The Day After Tomorrow (which depicts extremely rapid global cooling) because of the rapid cooling which would have to occur for McLean's prediction to come to fruition, as illustrated in Figure 1.
Figure 1: NCDC global average surface temperature from 1880 through 2010 (blue), McLean's 2011 prediction (orange), and the actual 2011 NCDC temperature (purple).
Posted on 10 February 2012 by John Hartz
This article is a reprint of a news release posted by the US Jet Propulsion Laboratory on Feb 8, 2012
In the first comprehensive satellite study of its kind, a University of Colorado at Boulder-led team used NASA data to calculate how much Earth's melting land ice is adding to global sea level rise.
The total global ice mass lost from Greenland, Antarctica and Earth's glaciers and ice caps during the study period was about 4.3 trillion tons (1,000 cubic miles), adding about 0.5 inches (12 millimeters) to global sea level. That's enough ice to cover the United States 1.5 feet (0.5 meters) deep.
Posted on 10 February 2012 by Tom Smerling
Is the increase in extreme weather due to climate change? This animated cartoon from the National Center from Atmospheric Research (NCAR) provides perhaps the clearest — and certainly the most entertaining — answer yet.
For more on the latest science exploring the links between extreme weather and climate change, check out NCAR's Doping the Atmosphere, and Extreme Weather Forensics; and SkS's Extreme Events Increase With Global Warming.
For a “bite sized” version of the steroids metaphor, check out “Putting the atmosphere on steroids” at Climate Bites, which also has a good post by John Russell about critics of The Escalator missing the point of the graphic.
Posted on 9 February 2012 by John Cook
The Hockey Stick and the Climate Wars by Michael Mann takes us into the heart of the climate change controversy via the scientist standing in the eye of the storm - Michael Mann. He provides an eye-opening account of the lengths the opponents of climate science will go to in their campaign to slander climate scientists and distract the public from the realities of human caused global warming.
Posted on 9 February 2012 by Alex C
The Wall Street Journal’s 27 January 2012 climate change op-ed came under harsh and swift criticism for being signed by only two climate scientists and fourteen other non-climate scientists, criticism most notably demonstrated by a group of 38 climate scientists in a response letter that the Journal has agreed to publish (to its credit). Apparently this strong show from experts in the field has not stopped Dr. Patrick Michaels, though, from nailing his colors to the mast at Forbes, and both promoting misrepresentation of the research of another scientist - Professor William Nordhaus - and misinforming the public on the consensus of evidence in climate science.
Michaels continuing the misrepresentation of Dr. William Nordhaus
Michaels starts his opinion piece by first contradicting another op-ed that appeared in the New York Times, written by Andrew Revkin. In his piece, Revkin cites an email exchange that he had with Sterling Professor of Economics at Yale University, Dr. William Nordhaus. For some quick background info, the Wall Street Journal op-ed stated:
Posted on 8 February 2012 by dana1981
The causes and even start and duration of the Little Ice Age (LIA), a global cooling event of approximately 0.5°C over several centuries ending in the late 19th Century, has been a challenge for climate scientists to pin down, with many possible contributing factors. A very interesting new paper by Miller et al. (2012) seeks to answer these questions by simulating the climate response to a number of large volcanic eruptions during the LIA timeframe. As the authors note, the challenge lies not only in determining the cause of the LIA, but when the event even started:
A similar paper, Anderson et al. (2008), was previously discussed here.
Miller et al. used precisely-dated records of ice-cap growth from Arctic Canada and Iceland in their attempt to assess the timing and duration of the LIA. The ice caps exhibit little or no flow, and thus preserve rooted tundra vegetation that was alive at the time of ice-cap expansion. This enabled the scientists to use carbon dating on the vegetation. This process accurately dates the time when snowline dropped below the vegetation altitude, killing the plants, and remained on average below that site until the summer warmth of recent decades. The locations from which Miller et al. gathered vegetation samples are illustrated in Figure 1.
Figure 1: Arctic Canada sites with recently exposed entombed plants dated younger than 800 AD (circles) and older than 800 AD (triangles); Hvítárvatn, Iceland (square); Greenland temperature borehole site and sea ice record on the North Iceland shelf (round).
Posted on 7 February 2012 by Ari Jokimäki
Scientists are telling about whats and whys:
Ozone has weekly lows and highs.
Yet another weekly paper batch, oh, isn't that nice...
Posted on 7 February 2012 by Rob Painting
As indicated in a press release from the NASA Jet Propulsion Lab last year, short-term trends in global sea level rise are greatly affected by temporary exchanges of water mass between the land surface and ocean - creating 'potholes' and 'speed bumps' in the sea level record. This a consequence of changes in precipitation (rainfall & snow) resulting from the El Niño-Southern Oscillation (ENSO).
During La Niña the sea surface is cooler-than-normal and rainfall is concentrated over land, which leads to a temporary fall in global sea level. With El Niño the surface of the tropical Pacific Ocean becomes warmer-than-normal, and rainfall gets concentrated over the ocean. This, combined with the drainage of water from land, causes a temporary spike in global sea level.
ENSO is principally responsible for the large year-to-year fluctuations evident in the global sea level record, but neither of these two phenomena (El Niño/La Niña) alter the long-term sea level rise which results from the melting of land-based ice, and the thermal expansion of the oceans as they warm. They do, however, cause sufficient 'noise' to obscure the long-term sea level rise when viewed at short intervals.
In the last two years two back-to-back La Niña have temporarily lowered sea level, but La Niña appears to have weakened in recent months and accordingly we would expect an uptick in sea level rise as conditions move closer to neutral. A quick look at AVISO confirms this, see Figure 1.
Figure 1 - The reference mean sea level since January 1993 (left) is calculated after removing the annual and semi-annual signals. A 2-month filter is applied to the blue points, while a 6-month filter is used on the red curve. By applying the postglacial rebound correction (-0.3 mm/year), the rise in mean sea level has thus been estimated as 3.18 mm/year. Image from AVISO.
Posted on 6 February 2012 by John Hartz
Kevin Trenberth's guest post, Check With Climate Scientists for Views on Climate is the response from a number of prominent climate scientsts to a letter signed by 16 scientists and engineers that was recently published in the Wall Street Journal. The "Gang of 16's" letter was also squarely addressed by Dana in The Latest Denialist Plea for Climate Change Inaction
Still Going Down the Up Escalator by Dana also garnered a lot of attention by commentors and other websites. MarkR's Measurements show Earth heating up, think tanks & newspapers disagree addressed denialist propaganda recently published in certain UK news outlets. The creative graphics embedded in the article also received attention by other websites.
Toon of the Week
H/T to Joe Romm's Climate Progress.
Major Study of Ocean Acidification Helps Scientists Evaluate Effects of Atmospheric Carbon Dioxide on Marine Life
Posted on 6 February 2012 by John Hartz
This is a reprint of a news release posted (Jan 23, 2012) on the website of the University of California Santa Barbara.
Might a penguin's next meal be affected by the exhaust from your tailpipe? The answer may be yes, when you add your exhaust fumes to the total amount of carbon dioxide lofted into the atmosphere by humans since the industrial revolution. One-third of that carbon dioxide is absorbed by the world's oceans, making them more acidic and affecting marine life.
A UC Santa Barbara marine scientist and a team of 18 other researchers have reported results of the broadest worldwide study of ocean acidification to date. Acidification is known to be a direct result of the increasing amount of greenhouse gas emissions. The scientists used sensors developed at Scripps Institution of Oceanography at UC San Diego to measure the acidity of 15 ocean locations, including seawater in the Antarctic, and in temperate and tropical waters.
The image shows a SeaFET pH sensor deployed underneath approximately 12 feet of sea ice in McMurdo Sound, Ross Island, Antarctica, in Oct. 2010. Scientists use these sensors to identify the natural dynamics of ocean pH in order to better understand how marine organisms may be impacted by climate change. The black object is the sensor, which is anchored to the ocean bottom using weights. Along the ocean bottom, worms and sea stars are visible.
Posted on 5 February 2012 by Rob Painting
In part 1 we saw that NASA scientists James Hansen, Reto Ruedy, Makiko Sato and Kwok-Wai Ken Lo from the Goddard Institute for Space Studies (GISS) have released an analysis of global temperature in 2011, and looked at future prospects. Reviewing the evidence, the authors concluded that rapid global warming is likely in the next few years. This is not a new phenomenon, but simply a reflection of natural variability, cool (La Niña) and warm (El Niño) phases which still exert a temporary cooling/warming influence on global surface temperatures even in the presence of a persistent global warming trend.
In part 2 we'll see that seasonal extreme warm anomalies in 2009-2011 are well above the 1951-1980 base period typically used in GISTEMP analyses - indicative of global warming's role in heatwaves. That measuring of manmade aerosols (pollution particles that reflect sunlight) is still highly problematic, and significantly, that the current warming phase of the 11-year solar cycle is likely to have a noticable warming effect on the climate over the next 3-5 years.
Figure 1 -Solar irradiance from composite satellite-based time series. Data sources: For 1976/01/05 to 2011/02/02 Physikalisch Meteorologisches Observatorium Davos, World Radiation Center and for 2011/02/03 to 2012/01/11 University of Colorado Solar Radiation & Climate Experiment. The circled area is (roughly) the solar energy already absorbed by the ocean and yet to manifest itself in global temperatures i.e - warming already committed.
Posted on 4 February 2012 by Ari Jokimäki
The Skeptical Science audience largely were not monitoring my new research of last week feature during last year (this is painfully obvious from the visitor counts of my blog), so I think a glimpse of that might be in order. One of the points highlighting some selected papers of last week is to show that climate science is cool. Therefore I decided to make a selection of cool climate papers of last year. While I'm browsing through new climate related science and looking at certain research paper, I frequently think that this is cool. Below you can see some of the studies from last year I thought were cool. There is one paper for each week and I have subjectively decided which is the coolest paper of that week. I won't listen to complaints but you are welcome to show your own selections.
Posted on 3 February 2012 by dana1981
The Escalator, originally created as a simple debunking to the myth "Global warming stopped in [insert date]", turned out to be a very popular graphic. Going Down the Up Escalator, Part 1 recently surpassed 20,000 pageviews, Part 2 has an additional 4,000+ views, and the graphic itself has been used countless times in other blogs and media articles. Due to its popularity, we have added a link to The Escalator in the right margin of the page, and it also has its own short URL, sks.to/escalator.
The popularity of the graphic is probably due to the fact that (1) it's a simple, stand-alone debunking of the "global warming stopped" myth, and (2) that particular myth has become so popular amongst climate denialists. As The Escalator clearly illustrates, it's easy to cherry pick convenient start and end points to obtain whatever short-term trend one desires, but the long-term human-caused global warming trend is quite clear underneath the short-term noise.
Posted on 2 February 2012 by Kevin Trenberth
In response to the latest denialist plea for climate inaction published in the Wall Street Journal (WSJ), the WSJ has published a response letter from a number of actual climate scientists, which is re-printed below.
Do you consult your dentist about your heart condition? In science, as in any area, reputations are based on knowledge and expertise in a field and on published, peer-reviewed work. If you need surgery, you want a highly experienced expert in the field who has done a large number of the proposed operations.
You published "No Need to Panic About Global Warming" (op-ed, Jan. 27) on climate change by the climate-science equivalent of dentists practicing cardiology. While accomplished in their own fields, most of these authors have no expertise in climate science. The few authors who have such expertise are known to have extreme views that are out of step with nearly every other climate expert. This happens in nearly every field of science. For example, there is a retrovirus expert who does not accept that HIV causes AIDS. And it is instructive to recall that a few scientists continued to state that smoking did not cause cancer, long after that was settled science.
Posted on 2 February 2012 by MarkR
The Global Warming Policy Foundation (GWPF) is a British political think tank that attacks climate science. Its commentary is often regurgitated by journalists at newspapers with similar political opinions on climate science such as the Daily Mail, Express and Telegraph (whose consulting science editor is a GWPF adviser).
Posted on 1 February 2012 by John Hartz
This is a reprint of a news release written by Sandra Hines and posted on the website of the University of Washington on Jan 26, 2012.
Stop wrangling over global warming and instead reduce fossil-fuel use for the sake of the global economy.
That’s the message from two scientists, one from the University of Washington and one from the University of Oxford in the United Kingdom, who say in the current issue of the journal Nature (Jan. 26) that the economic pain of a flattening oil supply will trump the environment as a reason to curb the use of fossil fuels.
“Given our fossil-fuel dependent economies, this is more urgent and has a shorter time frame than global climate change,” says James W. Murray, UW professor of oceanography, who wrote the Nature commentary with David King, director of Oxford’s Smith School of Enterprise and the Environment.
The “tipping point” for oil supply appears to have occurred around 2005, says Murray, who compared world crude oil production with world prices going back to 1998. Before 2005, supply of regular crude oil was elastic and increased in response to price increases. Since then, production appears to have hit a wall at 75 million barrels per day in spite of price increases of 15 percent each year.
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