While climate fluctuations are to be anticipated year to year, according to NASA scientists, the global temperatures of the previous year suggest a long-term warming trend. 2012 was the ninth hottest year since 1880, the year these climate studies began.
For those in the United States, this comes at no surprise: according to NOAA, the National Oceanic and Atmospheric Administration, 2012 ranks as the hottest year on record for the continental United States.
The global temperature analysis comes from NASA’s Goddard Institute for Space Studies in New York, which continually observes global temperatures. GISS compared 2012′s numbers to averages from the mid-20th century, and the increase is apparent: in 2012, the average temperature was about 58.3 degrees Fahrenheit (14.6 Celsius), 1.0 F (0.6 C) warmer than the average temperature of the mid-20th century.
Since global temperature records have been tracked, all of the nine warmest years on Earth–except one (1998)–have occurred since the year 2000. In addition, 2010 and 2005 are now tied for first place as the hottest recorded years.
According to NASA, the average temperature world-wide has risen approximately 1.4 degrees F (0.8 C) since 1880.
These statistics clearly show that the most recent decades have been hotter than those in the previous century.
This analysis of temperature coincides with the increase in greenhouse gas levels. It’s evident that, with these greenhouse gas increases, the global temperatures also will continue to rise, if not year to year, then decade to decade.
“One more year of numbers isn’t in itself significant,” according to Gavin Schmidt, a climatologist from the Goddard Institute. “What matters is this decade is warmer than the last decade, and that decade was warmer than the decade before. The planet is warming. The reason it’s warming is because we are pumping increasing amounts of carbon dioxide into the atmosphere.”
While greenhouse gases are also naturally occurring, this global increase in greenhouse gases has been consistent with the increase in emissions made by fossil-fuel burning machines. The rise in greenhouse gases is intimately related to the rise in temperature, as both have been increasing decade after decade.
Over 1,000 meteorological stations worldwide provide weather data for the GISS’s temperature analysis. Antarctic research stations and satellites observing the temperature of the oceans’s surfaces also provide the GISS with vital information to analyze the state of the globe’s temperatures. One program, open to the public, can calculate surface temperature changes for any given location and compare it to averages from 1951 through 1980. 1976 was the last year that was cooler than the average temperature from this three-decade period.
Precipitation in 2012, meanwhile, varied greatly across the planet. Major drought conditions continued to plague important agricultural regions in eastern Russia, Ukraine, Kazakhstan and central North America, according to NASA. The Arctic a;sp experienced a record-breaking ice-melt season in 2012, while in Antarctica scientists observed record-breaking ice-sheet extension into the ocean.