Hit or Miss? Extreme Weather vs. Climate Change
A destroyed home on Front Street in Union Beach, NJ Nov. 8, 2012, following the devastation from superstorm Sandy that hit the coast of New Jersey and New York areas.Ken Cedeno/Corbis
In 2012, the atmospheric effects from human activities influenced at least six extreme weather and climate events.
The study “Explaining Extreme Events of 2012 from a Climate Perspective,” released by the American Meteorological Society (AMS), analyzed 12 different events from 2012. Here are the six events they tied to human-induced climate change as well as two where they could not find a definitive link.
The first to top the list with a "hit" was Superstorm Sandy. The annual probability of a Sandy-like storm deluging New York, New Jersey and other parts of the East Coast has nearly doubled compared to 1950. Even weaker storms will be more damaging now than they were ten years ago because of rising sea levels.
The global sea level rises along with the temperature for two major reasons. For one, heat causes water to expand, which causes the existing water to take up more space and encroach on the coast. At the same time, ice at the poles and in glaciers melts and increases the amount of water in the oceans.
A polar bear (Ursus maritimus) swims beside an inflatable zodiac boat in open water in Hudson Bay, Canada, on a summer evening.Paul Souders/Corbis
On September 16, 2012, the National Snow and Ice Data Center reported that summer sea ice reached its smallest extent ever recorded since satellite images became available in 1979.
The authors of the AMS report stated that this unprecedented melting of the Arctic could not be explained by natural variability in the Earth's climate and weather patterns. In a few more decades, summer sea ice will likely disappear from the Arctic.
Polar bears, seals, whales, and other Arctic life evolved in the presence of summer ice for millions of years. These creatures may not be able to adapt to the rapid disappearance of the sea ice over the course of only a few decades. The people who depend on those animals for food and resources face an uncertain future as well.
A horse is cooled by the breeze of two fans run off a portable generator as it waits tied to its trailer in a field at Cowtown Rodeo in Woodstown, New Jersey July 7, 2012. The temperature was near 100 degrees Fahrenheit (38 degrees Celsius).Tom Mihalek/Reuters/Corbis
Dozens died from heat-related causes during the extremely high temperatures that tormented the United States during spring and summer of 2012. Many more were taken to the hospital for heat exhaustion.
AMS' analysis found that approximately 35 percent of the extreme heat in the eastern United States between March and May 2012 resulted from human activities' effects on climate. The report warned that deadly heat waves will become four times more likely in the north-central and northeastern United States as the planet continues to warm.
A woman sheltering under an umbrella at a street party in Morecambe, UK, to celebrate the Queen's Diamond Jubilee in 2012. Andrew Fox/Corbis
While the U.S. broiled and parched in 2012, many other areas were inundated, including the United Kingdom during Queen Elizabeth II's Diamond Jubilee (shown here) when the heaviest summer rains in a century fell on England.
The study authors noted that natural variability likely accounted for some of the abnormally intense British precipitation and subsequent flooding in 2012. However, they warned that climate change seems to be increasing rainfall totals. Warmer sea temperatures and more atmospheric moisture translates into an even greater need for umbrellas in England.
A female red kangaroo (Macropus rufus) pauses in a rain storm at Australia's Sturt National Park. The red kangaroo population increased dramatically after the recent rains in the previous 3 years following 8 years of drought.Theo Allofs/Corbis
Once, the sun never set on the British Empire. In 2012, the rain didn't stop in several parts of the British Commonwealth, or the Commonwealth of Nations, a group of countries made up of former territories of the sceptered isle's empire.
Extreme rainfall drenched southeastern Australia between October 2011 and March 2012. The La Niña cycle may have been mostly responsible for the heavy downpours. However, the probability of above-average Australian precipitation during March increased by 5 percent to 15 percent due to climate change, according to the AMS report.
The late sun catches a rain shower on Lake Wakatipu, Queenstown, New Zealand.Tim Clayton/Corbis
Deluges like the December 2011 two-day downpour in Golden Bay, New Zealand, may help stem droughts in the home of Middle Earth more frequently in the future. Kiwi rainfall may increase, wrote the study authors, due to a one to five percent increase in available atmospheric moisture that resulted from human-caused global climatic shifts.
That may come as good news, considering the massive drought they experienced this year.
Corn plants are seen in a drought-stricken farm field near Evansville, Indiana, July 18, 2012.John Sommers/Reuters/Corbis
However, the AMS report couldn't definitively put the climate blame on some events.
For example, computer simulations and analysis of weather records couldn't conclusively prove that the devastating 2012 drought across the United States directly resulted from human-caused climate change.
The report did find that the central United States has shown a slight trend towards wetter springs and drier summers, but climate models didn't conclusively point to a threat of more frequent drought in America's agricultural heartland in the future.
A heavy rainstorm flooded the town of Chongqing, China on July 22, 2012.Corbis
Similarly to the U.S. drought but on the opposite end of the moisture spectrum, the AMS report acquitted climate change of direct culpability in the July 2012 extreme rainfall that flooded portions of north China and southwestern Japan. The AMS report used a combination of computer simulations and historical data to parse out natural variations from human-caused climate change. If there wasn't a smoking climate change gun, the researchers avoided asserting human influences on weather disasters.