Katherine Bagley's articles

In recent years, the world's scientists have begun to show that climate change is altering the magnitude and frequency of severe weather, and polls say a majority of Americans now link droughts, floods and other extremes to global warming.

And yet, this country's TV weather forecasters have increasingly taken to denying evidence that warming is affecting weather—or is even happening at all. Only 19 percent accept the established science that human activity is driving climate change, says a 2011 report by the George Mason University Center for Climate Change Communication, making TV meteorologists far more skeptical than the public at large.

The revelation last month that the Heartland Institute, a libertarian group based in Chicago, is trying to teach climate skepticism in schools has sparked a flurry of criticism and debate over the entry of global warming doubt into the classroom.

But how easy is it, really, for a group with an ideological mission to influence science curricula?

While it is hard to judge how Heartland will fare, climate denial materials have already begun to creep into public schools, said O. Roger Anderson, chair of the math and science department at Teachers College of Columbia University, in an interview. That's what Anderson says concerns him.

A number of prominent U.S. climate scientists who identify themselves as Republican say their attempts in recent years to educate the GOP leadership on the scientific evidence of man-made climate change have been futile. Now, many have given up trying and the few who continue notice very little change after speaking with politicians and their aides.

"No GOP candidates or policymakers want to touch the issue, and those of us trying to educate them are left frustrated," Kerry Emanuel, an atmospheric scientist at the Massachusetts Institute of Technology and a registered Republican, told InsideClimate News. "Climate change has become a third rail in politics."

Record heat waves, drought, floods, thunderstorms, tornado outbreaks—extreme weather battered much of the United States and parts of the world in recent years, causing an unprecedented number of deaths and economic losses.

What role has global warming played, if any?

The answer has implications that go beyond the ideological debate in U.S. politics over climate change. It affects, among other things, the future direction of the 19-year-old U.N. Framework Convention on Climate Change (UNFCCC), the main forum for the global fight to limit warming. To date its priority has been emissions cuts, or "mitigation," to keep climate change in check. But is it too late for that, as some scientists now say? Is it time for "adaptation" (finding ways to live with heat waves, rising seas and flooded coastlines and scarcer water and food supplies) to finally share focus and UNFCCC resources?

Growing scientific evidence indicates that the answer to that question is yes.

Severe weather in the United States and elsewhere has grown more frequent since 1980. Contributing to the shift is the accumulation of heat-trapping carbon dioxide in the air from human activities—though teasing out the exact contribution is tricky. 

As usual with climate science, there are uncertainties and complexities in the data on climate extremes, and skeptics have pounced on the unknowns to exaggerate doubts about the consensus on climate change and to make the case for inaction. To counter those charges, the UN Intergovernmental Panel on Climate Change (IPCC), the world's leading scientific body on global warming, has produced a new report designed especially for the world's politicians that tries for the first time to clarify the link between wild weather and global warming. 

Specifically, the authors of the Special Report for Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) wanted to know what the research says about whether greenhouse gas emissions cause extreme weather; who is, and will be, hardest hit by these disasters; and how can governments and organizations lessen the impacts.

In this primer InsideClimate News takes a look at what the IPCC gleaned from its two years of research into these questions.

Has "anthropogenic," or human-caused, climate change already altered the frequency of extreme weather events?

For more than a decade, carbon capture and storage technology has been heralded by fossil-fuel industries and many policymakers and scientists as an effective response to the threat of climate change.

But the commercialization of CCS—which captures heat-trapping CO2 from smokestacks and pumps it into reservoirs deep underground—still faces enormous financial, technological, political and environmental hurdles.

One question that critics want answered is what happens if mass quantities of CO2 leak out and collect in communities' air or water.

Conservationists and health organizations warn that a large release of CO2 could contaminate drinking water supplies, cause asphyxiation or alter pH levels in the blood of residents, which can lead to brain malfunction or death. The industry and other supporters say that natural sequestration events and 20 years of carbon injection by oil companies suggest that CO2 can be trapped underground safely and permanently.

A new study from scientists at the University of Edinburgh in Scotland, which was partially funded by industry, claims to clear up at least some of that uncertainty.

The researchers looked at death rates near natural CO2 seeps in Italy over a 50-year period. They found that people living near the storage sites have a one-in-a-32 million annual chance of dying from contamination. The researchers note in the paper that there is a greater chance of winning the lottery than being killed by natural CO2 releases.

In the past two decades scientists have concluded that climate shifts helped drive many of history's biggest conflicts—from the collapse of the Mayan civilization around 800 AD to the French Revolution beginning in 1789.

But the impact of climate on violence in modern societies, which are considered more technologically and politically adept at dealing with chaotic weather, remains controversial.

Includes corrections

Arctic sea ice could disappear completely by 2060 in the summer months due to accelerated warming from both a buildup of human-caused greenhouse gases and the planet's natural greenhouse effect, a group of scientists from the National Center for Atmospheric Research concluded in a new study.

However, the researchers said they still can't predict with certainty whether sea ice will retreat or expand during the next decade.

That finding keeps alive a scientific puzzle that has persisted for years, with implications that reach beyond academic circles.

Getting the question resolved is of mounting interest for businesses and countries, who are eager to tap economic opportunities of the melting Arctic as it opens the region to commercial shipping and oil exploration. By contrast, some climate skeptics opposing greenhouse gas regulation policies in Congress and other governments have an interest in bolstering the scientific uncertainty. 

In an interview with SolveClimate News, Jen Kay, NCAR climate scientist and lead author of the research, said the study shows that predicting what will happen to Arctic sea ice from now until 2020 is tricky, because of the unpredictable effects that winds, clouds and temperature changes have on patterns of atmospheric circulation. These natural fluctuations are too volatile to be trusted when incorporated into climate models, she said.

However, "according to our research greenhouse gases are definitely affecting the ice," Kay said, cognizant of how the study's ambiguity on the politically charged issue may be interpreted.

During the industrial boom of the mid-twentieth century thousands of man-made chemicals were created to make chemical processes and products stronger and more durable.

The substances became useful in pest control and crop production, but it wasn't long before they also proved deadly, causing cancers, birth defects and other health problems.

Known as persistent organic pollutants (or POPs), this group of the world's most toxic compounds takes decades to degrade as they circulate through Earth's oceans and the atmosphere, gradually accumulating in the fatty tissues of humans and wildlife.

Once the connection between POPs and toxicity was scientifically proven, wealthy governments sprang into action to reduce the risks, eventually restricting or banning the use of 12 pollutants,  including DDT and polychlorinated biphenyls (PCBs), at the 2001 Stockholm Convention on POPs.

Climatic forces were also helping to limit the chemicals' global reach.

In places like the Arctic, cold temperatures trapped POPs in snow, soil and oceans capped by sea ice, as the long-lived pollutants circled through the region. Between the POPs settling into the Arctic and other sinks — and the international campaign to regulate the chemicals — atmospheric levels of POPs steadily declined during the past decade.

New research, however, suggests that global warming is reversing this downward trend.

Rising ocean temperatures due to global warming have already been linked to coral reef deaths, destructive storms, shifting species distributions and harmful algal blooms. Now, a team of Australian researchers is adding a new and similarly daunting concern to that list: the spread of disease in "habitat-forming" seaweeds that are critical to marine health. 

Scientists fear that the widespread loss of these seaweeds could have disastrous effects on creatures that rely on them for food and protection, such as sea hares, sea urchins and dozens of fish and invertebrate species.

"Seaweeds are the 'trees' of coastal temperate systems," said Peter Steinberg, a marine biologist at the University of New South Wales and director of the Sydney Institute of Marine Science, who helped lead the research that was published in the journal Global Change Biology last month.

"They provide the food and habitat for many of the other organisms that live there. Without them, these systems are radically different," he said.

Earlier studies documented rapid decline and disease in seaweeds during the past two decades, but this analysis was the first to examine whether climate change is driving illness in habitat-forming stands that provide life to vast numbers of marine organisms.

Rapidly thinning sea ice on Canada's Hudson Bay will trigger a fast rate of species loss and open new access to commercial shipping and crude oil exploration, the authors of a new study suggest.

The study provides the most comprehensive look yet at how climate change will affect the Texas-sized Hudson Bay, a biologically and economically important inland sea in the country's northeast.

Summer sea surface temperatures will increase 9 degrees Fahrenheit in the southeastern Hudson Bay and 5.4 degrees Fahrenheit in the central portion before mid-century, spelling disaster for sea ice formation and the polar bears and other wildlife that depend on the ice to survive, according to the study.

The bay's western edge is home to one of the world's largest clusters of polar bears.

The scientists calculate that within 30 years the 316,000-square-mile water body could lose 31 percent of its total volume of ice. Since the 1950s, Canada's average temperatures have been steadily increasing from the rise in emissions of carbon dioxide and other heat-trapping gases.