Average temperatures across the country have risen by one degree Fahrenheit.
Opponents of the climate change ‘theory’—that human activity is raising global temperatures—have an increasingly difficult case to make, in light of recently released scientific evidence.
2012 was the “warmest and second most extreme year on record” for the contiguous U.S., according to data published by the National Climatic Data Center, a branch of the National Oceanic and Atmospheric Administration.
Last year’s average temperature of 55.3 degrees fahrenheit shattered the previous 1998 record by a full degree. Differences between years are normally measured in fractions of a degree.
“The heat was remarkable,” said Jake Crouch of the National Climatic Data Center in Asheville, N.C., which released the climate data Tuesday. “It was prolonged. That we beat the record by one degree is quite a big deal.”
2012 saw a record-setting heatwave in March, a devastating drought in the Corn Belt, and a rare and destructive hurricane on the eastern seaboard. Federal temperature records indicate that 34,008 daily high temperature records were set at weather stations scattered across the country, along with 6,664 record lows– evidence of the increasing volatility of our weather patterns.
In the 1970s the ratio of extreme highs to lows in the U.S. was roughly in balance, though it has been tilting in favor of higher temperatures over the decades. Now the ratio has reached approximately 5:1.
Scientists, acknowledging the role of natural variability in last year’s extreme heat and drought, said that global warming was almost certainly a factor. They warned that 2012’s heat was probably only a taste of what’s to come, as China and other developing countries continue to industrialize and produce copious amounts of greenhouse gasses.
Although a cooling La Niña weather pattern last year means that the global temperature is unlikely to have set a record high, it is still expected to have been the world’s eighth- or ninth-warmest year on record.
This means that on a global scale, the 10 warmest years on record all fell within the past 15 years, according to a recent article in the New York Times.
Last year 61 percent of the United States was embroiled in a drought, which dried the soil in the March planting season and scorched crops in record-setting July temperatures. A concurrent drought in Europe severely impacted global food output and sent prices sharply upward.
2012 was not only the country’s warmest yet, but the second most extreme (after 1998), according to the Climate Extremes Index.
October’s Hurricane Sandy, August’s Hurricane Isaac, and a rare derecho that generated destructively high winds across the central and eastern United States are among the 11 natural disasters in 2012 that have caused $1 billion or more in damages. Extreme variations in temperature tend to cause such phenomena.
As the nation-wide drought continues into the new year, the country will likely continue to feel the consequences of climate change, be it in terms of food prices, natural disasters, or weeks of 100 degree-plus temperatures.
The problem is a global one, and difficult to address both politically and economically. But it is about time the U.S. took a leading role by both acknowledging that global warming exists, and doing something about it.