Recent extreme weather prompting climate change discussion

With heat waves, a strong derecho, wildfires and widespread drought defining this year’s weather in the U.S., many are questioning if climate change is affecting us already.

“It’s clear that when we look at the consequences of climate change, that it’s in severe weather where we are going to see effects,” climate scientist Don Wuebbles of the University of Illinois at Urbana-Champaign told USA Today.

More than 40,000 daily heat records have been broken around the country so far this year, according to the National Oceanic and Atmospheric Administration. Last year, only 25,000 daily records had been set by July, according to Yahoo! News.

Although the first five months of 2012 have been the hottest on record in the contiguous U.S.  —  July was the hottest month in 117 years of records— , land and ocean temperatures, considered together, are only the 10th-hottest on record worldwide in 2012, at least so far, according to NOAA.

A 2010 report by the U.S. National Academy of Sciences reports that average surface temperatures have increased about 1.4 degrees Fahrenheit worldwide during the past century. In 2010, the National Research Council published three reports saying that “the U.S. should act now to reduce greenhouse gas emissions and develop a national strategy to adapt to the inevitable impacts of climate change.”

In late June, a derecho — a fast-moving, long-lived, large and violent land-based storm — brought winds gusting at 60-80 mph, resulting in extensive damage and power outages for millions across the Mid-Atlantic and parts of the Midwest.

One of the worsts droughts in years has affected areas nationwide. Drought classified as sever to extreme currently covers a large portion of the contiguous U.S. (see the image at left for more detail). In addition, more than 50 percent of all U.S. counties have been declared disaster areas, according to the Los Angeles Times.

This summer, fires raged in Colorado, New Mexico, and more recently California, Idaho, Oregon, Utah and Montana.

Over the past weekend, fires in the West prompted a number of evacuations, and high temperatures, low humidity and possible lightning in many areas made containment of the blazes difficult.

Though this year’s extreme weather is shaping up to be some of the worst on record, 2011 had its fair share of records with tornadoes (like this one in Joplin, Mo.), floods in the Missouri and Mississippi Rivers and droughts and wildfires in Oklahoma.

But it doesn’t stop there.

In 2010, extreme weather occurred all over the planet. Australia had the worst flooding in four decades, covering an area larger than France and Germany combined, according to Environmental Graffiti.

Russia’s hottest summer on record, combined with a bad drought and subsequent wildfires, led to 50,000 deaths. Although a NOAA report found that the Russian heat wave was not indicative of a long-term warming trend, the report did concede: “Nevertheless, there is evidence that such warming has contributed to observed heat waves in other regions, and is very likely to produce more frequent and extreme heat waves later this century.”

Pakistan suffered from floods that washed away vital infrastructure, including more than 5,000 miles of roads and railways.

And the U.S. had record winter cold and snow after one of the hottest summers on record.

Local weather patterns temporarily influence people’s beliefs about evidence for global warming, according to research by political scientists at New York University and Temple University. Their study, which appears in the Journal of Politics, found that those living in places experiencing warmer-than-normal temperatures at the time they were surveyed were significantly more likely than others to say there is evidence of global warming.

“Global climate change is one of the most important public policy challenges of our time, but it is a complex issue with which Americans have little direct experience,” Patrick Egan of NYU and Megan Mullin of Temple noted. “As they try to make sense of this difficult issue, many people use fluctuations in local temperature to reassess their beliefs about the existence of global warming.”

Of more than five national surveys of American adults sponsored by the Pew Research Center, 73 percent of respondents agreed that the earth is getting warmer, though a NYU article states that Egan and Mullin measured the potential impact of temperature on individuals’ opinions by looking at zip codes from respondents in the Pew surveys and evaluating the relationship between their responses and local weather data from the time they were polled.

Their results showed that an abnormal shift in local temperature corresponded with significant shifts in beliefs about global warming evidence. Typically, they found that warmer temperatures led to responses expressing belief in global warming (and vice versa for colder temperatures).

After taking into account other variables that may explain the results — such as existing political attitudes and geography — the study found the results still held.

ESSIC professor Raghu Murtugudde agrees with Egan’s opinion about the importance of climate change
to public policy, as he said in a June ESSIC article that one aspect of global climate change, sea level rise, is “a tremendous national security issue” because of the threat that this climate event directs at Naval assets such as the Norfolk Naval Station, not to mention Washington D.C., with its proximity to the rising Chesapeake Bay.

Sinead Farrell, an assistant research scientist with ESSIC and NOAA who was involved in NASA’s Project IceBridge mission to measure the extent of ice melting in the Arctic and Antarctic, said that part of the debate about climate change is due to confusion between what is actual data and what is projected for the future based on that data.

Even with data, future conditions – including the existence and extent of climate change – will be very difficult to predict more than a few years in advance. However, she was confident with one prediction based on her experiences in the field.

“Based on the evidence we have, we’re going to continue to warm the climate and melt more ice,” she said.


For more on this topic, check out this article about recent extreme weather raising questions about climate change and the most recent issue of the Climate Change Weekly Roundup.