Global temperatures have warmed significantly since 1880, the beginning
of what scientists call the "modern record." In this animation of temperature data from 1880-2011, reds indicate temperatures higher than the average during a baseline period of 1951-1980, while blues indicate lower temperatures than the baseline average.
A sobering report on the "State of the Climate," and our planet, Earth. Last year was one of the 10 warmest years on record, researchers from the National Oceanic and Atmospheric Administration said Tuesday. While the past 150 years have seen average temperatures rise 1.8 degrees Fahrenheit, 9 of the 10 hottest years on record have been since the 1990s—with 2012 ranking somewhere around 8 or 9. Arctic sea ice reached record lows during the summer, while 97 percent of all of Greenland ice melted in the winter—far more than average. Of particular importance in the NOAA report was the rise in ocean heat storage, which reached record levels in 2012. The surface temperature of the oceans was among the 11 warmest on record, and sea levels also reached a record high.
"The NOAA report underscored the effect that oceans have on temperatures. Oceans store much of the planet's heat, but ocean heat storage is at near-record levels, the report said, and increases were detected even in the ocean's depths.
But as oceans trap heat from a warming planet, they change. Surface ocean temperatures in 2012 were among the 11 warmest on record. In a study recently published in the journal Nature and Climate Change, Australian researchers reported that warmer seas have led to profound changes in marine life, including more species moving to the relatively cooler water of the poles.
Sea levels reached a record high in 2012, climbing 1.3 inches per decade since satellite tracking of sea levels began in 1993, NOAA said.
The Arctic also underwent "unprecedented change" and the warming trends there broke several records, the report said. For instance, the sea ice over the Arctic "shrank to its smallest 'summer minimum' extent since satellite records began 34 years ago."
Because the ice caps act as the planet's "air conditioners," scientists say, less Arctic ice means less ability to reduce heat."
Even average measurements indicating "normal" trends sometimes masked extreme swings in regional weather, according to the NOAA. For example, global average rainfall was "unremarkable," but much of the nation experienced extreme drought last year, yet the Sahel region of Africa had record rains and flooding during its wet season. Now this year, approximately 87% of the U.S. Western states are in drought.
"The latest 'State of the Climate' report shows that the Earth continues to heat, the atmosphere is heating, the worldwide ice loss continues, and other symptoms of our warming planet march forward, without cessation," said John P. Abraham, professor of thermal sciences at the University of St. Thomas in St. Paul, Minnesota. "A lot of people claim that global warming has magically stopped, but the facts, and the Earth, continue to disagree."