Graphs of the Day: Global Temps 2011
January 23, 2012
Nine of the top ten warmest years in the modern meteorological record have occurred since the year 2000. Last year was another one of them, coming in at 9th warmest since 1880.
The map above shows temperature anomalies, or changes, by region in 2011; it does not depict absolute temperature. Essentially, the map shows how much warmer or cooler each region was in 2011 compared with an averaged “base period” from 1951–1980. The line plot shows yearly temperature variations (from the base period average) for every year from 1880 to now. (For more explanation of how the analysis works, read World of Change: Global Temperatures.)
On January 19, 2012, researchers at NASA’s Goddard Institute for Space Studies (GISS) released their annual analysis of global temperatures, noting that Earth’s land and ocean surfaces continue to experience higher temperatures than several decades ago. The global average temperature for 2011 was 0.92 degrees Fahrenheit (0.51 Celsius) higher than the mid-20th century baseline.
“We know the planet is absorbing more energy than it is emitting,” said GISS director James Hansen. “So we are continuing to see a trend toward higher temperatures. Even with the cooling effects of a strong La Niña influence and low solar activity for the past several years, 2011 was one of the ten warmest years on record.”
It is important to note that during La Nina years like the current one, although the planet continues to absorb more heat than it emits, cool waters upwelling in the Pacific suck a lot of that heat out of the atmosphere – affecting weather around the globe, and causing thermometer readings to dip. This year was, however, the warmest la nina year in the record, as the graph below (from NOAA) shows.
Despite a strong La Nina event cooling the Pacific Ocean, 2011 was about the 10th hottest year on record, scientists have found. “It’s clear over time the El Niño years tend to be the warmer years and the La Niña years tend to be the cooler years,” said Tom Karl, director of NOAA’s National Climatic Data Center. “This year the La Niña-related temperatures for 2011 were as warm as anything we’ve seen in the past, very close to the year 2008.” Every year since 1976 has been warmer than average, according to NOAA. While 2011 was the coolest year in the 21st century, it was tied with the second-warmest year of the 20th century, notes Climate Central’s Andrew Freedman.
The Earth is warming up. The rate of warming has increased in the past century or so. This corresponds to the time of the Industrial Revolution, when we started dumping greenhouse gases into the atmosphere. Greenhouse gases warm the planet (hence the name) — if they didn’t we’d have an average temperature below the freezing point of water. Carbon dioxide is a greenhouse gas which is dumped into the atmosphere by humans to the tune of 30billion tons per year, 100 times the amount from volcanoes. And finally, approximately 97% of climatologists who actually study climate agree that global warming is real, and caused by humans.