Climate-change denial getting harder to defend

As temperatures in the Norwegian Arctic beat those in the denialists’ favourite, the Medieval Warm Period, comes this:

The United States experienced the warmest July in its history, with more than 3,000 heat records broken across the country. Overall, the summer was the nation’s third warmest on record and comes in a year that is turning out to be the hottest ever. High temperatures along with low precipitation generated drought conditions across 60% of the Lower 48 states, which affected 70% of the corn and soybean crop and rendered part of the Mississippi River non-navigable. Arctic Sea ice declined to a record low, and a surface thaw swept across 97% of the Greenland ice cap.

Though it’s not possible to definitively link any of these individual events to human-caused climate change, the summer’s extreme weather follows clear longer-term trends and is consistent with climate model projections. This was the 36th consecutive July and 329th consecutive month in which global temperatures have been above the 20th century average. In addition, seven of the 10 hottest summers recorded in the United States have occurred since 2000. Such rising temperatures and climate anomalies have been documented around the world.

But there’s also one bit of good news: The increasingly powerful evidence of a long-term warming trend is making climate-change denial more difficult to defend. Take “Climategate” — the argument that scientists have based their evidence for global warming on fraudulent science. The Koch Foundation provided funding to physicist Richard Muller of UC Berkeley, a longtime climate-change skeptic, to disprove the widespread consensus on global warming. Instead, his re-analysis showed the exact same warming trend found by the Intergovernmental Panel on Climate Change and other scientists.

Since completing his research last year, Muller has been vociferously speaking out on the reality of human-caused climate change, including in testimony before Congress. The publication this spring of an expanded weather station analysis by Britain’s Hadley Centre further confirms the trend and suggests Northern Hemisphere surface warming was about 0.1 degree Celsius greater than previously thought. With Muller’s and the Hadley Centre’s re-analysis, the idea of Climategate has become virtually impossible to take seriously. The planet is warming.

But that hasn’t silenced the climate-change deniers entirely; they’ve simply shifted their arguments. Increasingly, they are accepting evidence of recent warming, but they deny that it is largely caused by humans, attributing it instead to natural factors such as solar variability or the El Niño system. But these arguments don’t fly any better than their original ones.

Research by Grant Foster of the United States and Stefan Rahmstorf of Germany has shown that recent variations in the solar cycle, volcanic activity and El Niño/La Niña events actually had a tempering effect on warming. Similarly, Markus Huber and Reto Knutti of the Institute for Atmospheric and Climate Science in Zurich found by using simulation models that non-greenhouse gas factors could have accounted for only about 1% of the warming experienced since 1950. And this summer a team headed by Peter Gleckler of Lawrence Livermore National Laboratory provided strong evidence that the recent warming of the ocean surface could be traced to human activities. The evidence is now overwhelming that by and large the warming we are seeing has an anthropogenic cause.

Another common theme of the skeptics recently is that even if anthropogenic climate change is real, projections overstate future warming. Writing in August in the Wall Street Journal, physicists Roger Cohen (a retired ExxonMobil executive), William Happer of Princeton and Richard Lindzen of MIT — all noted climate skeptics — asserted that greenhouse gases, though possibly having a warming effect, were “unlikely to increase global temperature more than about one degree Celsius.”

That 1-degree Celsius, or 1.8-degree Fahrenheit, projection is based largely on a 2011 paper by Lindzen and contradicted by much other research. The Coupled Model Intercomparison Project Phase 5, for example, which represents about 20 climate modeling groups, has in 2012 generated more than 200 submissions and peer-reviewed publications testing and analyzing the newest climate models. The sum result of these improved models reaffirms the 2007 Intergovernmental Panel’s projections of an increase in global temperature of 4 to 8 degrees Fahrenheit by 2100. It is important for scientists to further refine such projections, but it’s clear that increasing greenhouse gases are likely to cause a significant rise in global temperatures.

(My emphasis in bold)

Source

 

Climate Change: An Information Statement of the American Meteorological Society

Here’s the final remarks from the full statement

Final remarks

There is unequivocal evidence that Earth’s lower atmosphere, ocean, and land surface are warming; sea level is rising; and snow cover, mountain glaciers, and Arctic sea ice are shrinking. The dominant cause of the warming since the 1950s is human activities. This scientific finding is based on a large and persuasive body of research. The observed warming will be irreversible for many years into the future, and even larger temperature increases will occur as greenhouse gases continue to accumulate in the atmosphere. Avoiding this future warming will require a large and rapid reduction in global greenhouse gas emissions. The ongoing warming will increase risks and stresses to human societies, economies, ecosystems, and wildlife through the 21st century and beyond, making it imperative that society respond to a changing climate. To inform decisions on adaptation and mitigation, it is critical that we improve our understanding of the global climate system and our ability to project future climate through continued and improved monitoring and research. This is especially true for smaller (seasonal and regional) scales and weather and climate extremes, and for important hydroclimatic variables such as precipitation and water availability.

Technological, economic, and policy choices in the near future will determine the extent of future impacts of climate change. Science-based decisions are seldom made in a context of absolute certainty. National and international policy discussions should include consideration of the best ways to both adapt to and mitigate climate change. Mitigation will reduce the amount of future climate change and the risk of impacts that are potentially large and dangerous. At the same time, some continued climate change is inevitable, and policy responses should include adaptation to climate change. Prudence dictates extreme care in accounting for our relationship with the only planet known to be capable of sustaining human life.

Scare tactics and modern day McCarthyism used against climate scientists

Aggressive deniers practice a form of asymmetric warfare that is decentralized and largely immune to reasoned response. They launch what Aaron Huertas, a press secretary at the Union of Concerned Scientists, calls “information missiles,” anti-climate-change memes that get passed around on listservs, amplified in the blogosphere, and picked up by radio talk-show hosts or politicians. “Even if they don’t have much money, they are operating in a structure that allows them to punch above their weight,” Huertas says.

The evidence to support the theory of anthropogenic, or human-caused, climate change has been mounting since the mid-1950s, when atmospheric models predicted that growing levels of CO2 in the atmosphere would add to the natural “greenhouse effect” and lead to warming. The data was crude at first, and opinions vacillated (skeptics like to recall a 1974 Time cover story that predicted an impending ice age). But by the mid-1990s, thousands of lines of independent inquiry supported the conclusion summarized in the 1995 IPCC report: “The balance of evidence suggests a discernible human influence on global climate.”

Since then, the case for anthropogenic climate change has only strengthened; 98 percent of actively publishing climate scientists now say that it is undeniable. But several finer points remain unsettled. For instance, researchers still don’t completely understand the role of aerosols in the atmosphere, the variable effects of clouds at different heights, and the influence of feedback mechanisms such as the changing reflectivity of the Earth’s surface and the release of gases from permafrost or deep seabeds. Climate-change skeptics have been keen to capitalize on those gaps in knowledge. “They play up smaller debates,” says Francesca Grifo at the Union of Concerned Scientists, “and divert the dialogue by attacking particular aspects. They represent climate science as a house of cards, where you pull out one and it all falls apart.”

In March 2001, George W. Bush’s administration declared that climate science was “too uncertain” to justify action (such as ratifying the Kyoto treaty) that might put the brakes on economic growth. That refrain would be echoed again and again, weakening or derailing successive international agreements and domestic policy. How had a small band of non-scientists managed to so quickly and thoroughly pursuade the nation’s leaders to reject an ever more coherent and definitive body of scientific evidence?

“It’s that false balance thing,” Mann says. “You’re a reporter and you understand there’s an overwhelming consensus that evidence supports a particular hypothesis—let’s say, the Earth is an oblate spheroid. But you’ve got to get a comment from a holdout at the Flat Earth Society. People see the story and think there’s a serious scientific debate about the shape of the Earth.”

“When I get an e-mail that mentions my child and a guillotine,” Hayhoe says, “I sometimes want to pull a blanket over my head. The intent of all this is to discourage scientists. As a woman and a mother, I have to say that sometimes it does achieve its goal. There are many times when I wonder if it’s worth it.”

As drivers crawled along Chicago’s busy Eisenhower Expressway, they were confronted with a large billboard that compared believers in global warming with Ted Kaczynski, the Unabomber. The text on the billboard read, “I still believe in global warming. Do you?” The advertisement was meant to be the first in a series. Others would liken climate-science advocates to mass murderers, including Charles Manson and Osama bin Laden. Bast did not respond for comment following the launch of the campaign, but Heartland issued a press release: “The people who believe in man-made global warming are mostly on the radical fringe of society. This is why the most prominent advocates of global warming aren’t scientists. They are murderers, tyrants, and madmen.”

“There are powerful voices of unreason,” says Ben Santer, who led the 1995 IPCC team, “but every year, the science becomes stronger and the data are telling an ever more consistent story.” As with tobacco, the more consistent the scientific story, the more difficult it will become for skeptics to reject anthropogenic climate change. That point was driven home after the Charles Koch Foundation donated $150,000 toward a study by Richard Muller, a physicist at the University of California at Berkeley who was, at the time, a darling of the climate-skeptic community. Muller spent two years investigating claims by global-warming deniers that temperature rises verified by multiple studies were skewed because of flawed analysis, unreliable weather stations and the effect of urban heat islands. Muller and his research team (which included Saul Perlmutter, the joint winner of the 2011 Nobel Prize in Physics) compiled 1.6 billion readings at 39,000 sites and examined other historical data.

Muller’s conclusion was most likely not what the Koch brothers had in mind. Last October, his team announced that the global mean temperature on land had increased by 1.6 degrees since 1950, a result that matched the numbers accepted by the mainstream climate-science community. “The skeptics raised valid points, and everybody should have been a skeptic two years ago,” Muller told me. “Now we have confidence that the temperature rises previously reported had been done without bias. Global warming is real.”

Just as in the rest of the country, belief in human-caused climate change in Oklahoma has been rising with the thermometer—according to Krosnick, a large majority of Inhofe’s constituents now believe that anthropogenic global warming is real. I ask Inhofe if he’s noticed any climate changes in his home state, such as last summer’s unprecedented heat and severe drought, withering crops, wild fires and dramatically expanded tornado season. “There’s not been any warming,” he snaps. “And there’s actually been a little bit of cooling. It’s all documented. Look at the Dust Bowl. Back then it was a lot hotter. Matter of fact, now they say the hottest time was actually during that time—1934, I guess.”

Actually, last summer’s average temperature of 86.9˚ was the highest ever recorded in Oklahoma. And last spring’s drought, when hundreds of farmers abandoned livestock they could no longer manage to feed or water, was the worst since 1921.

Many of the scientists I’ve spoken with say that no single act of harassment or intimidation has stung more than Inhofe’s “list of 17,” the call for the congressional investigation of prominent climate scientists. Mann, I tell Inhofe, said it “smacked of modern-day McCarthyism.”

Source

Why the Global Warming Skeptics Are Wrong

The threat of climate change is an increasingly important environmental issue for the globe. Because the economic questions involved have received relatively little attention, I have been writing a nontechnical book for people who would like to see how market-based approaches could be used to formulate policy on climate change. When I showed an early draft to colleagues, their response was that I had left out the arguments of skeptics about climate change, and I accordingly addressed this at length.

But one of the difficulties I found in examining the views of climate skeptics is that they are scattered widely in blogs, talks, and pamphlets. Then, I saw an opinion piece in The Wall Street Journal of January 27, 2012, by a group of sixteen scientists, entitled “No Need to Panic About Global Warming.” This is useful because it contains many of the standard criticisms in a succinct statement. The basic message of the article is that the globe is not warming, that dissident voices are being suppressed, and that delaying policies to slow climate change for fifty years will have no serious economic or environment consequences.

My response is primarily designed to correct their misleading description of my own research; but it also is directed more broadly at their attempt to discredit scientists and scientific research on climate change. I have identified six key issues that are raised in the article, and I provide commentary about their substance and accuracy. They are:

• Is the planet in fact warming?

• Are human influences an important contributor to warming?

• Is carbon dioxide a pollutant?

• Are we seeing a regime of fear for skeptical climate scientists?

• Are the views of mainstream climate scientists driven primarily by the desire for financial gain?

• Is it true that more carbon dioxide and additional warming will be beneficial?

As I will indicate below, on each of these questions, the sixteen scientists provide incorrect or misleading answers. At a time when we need to clarify public confusions about the science and economics of climate change, they have muddied the waters. I will describe their mistakes and explain the findings of current climate science and economics.

…continues here: Why the Global Warming Skeptics Are Wrong by William D. Nordhaus | The New York Review of Books.