NASA, NOAA Analyses Reveal Record-Shattering Global Warming Temperatures in 2015
According to NASA and the National Oceanic and Atmospheric Administration (NOAA), 2015’s global temperature average was 1.62ºF above the 1901-2000 average, making 2015 “by far the warmest year on record”. Ten of 2015’s monthly global temperatures tied or broke existing records.
Globally-averaged temperatures in 2015 shattered the previous mark set in 2014 by 0.23 degrees Fahrenheit (0.13 Celsius). Only once before, in 1998, has the new record been greater than the old record by this much.
NOAA scientists concur with the finding that 2015 was the warmest year on record based on separate, independent analyses of the data.
“Climate change is the challenge of our generation, and this issue affects every person on Earth,” said NASA Administrator Charles Bolden. “Today’s announcement should make policy makers stand up and take notice – now is the time to act on climate.”
Global concentrations of carbon dioxide in Earth’s atmosphere surpassed 400 parts per million for a monthly average in spring, 2015, breaching a symbolic barrier set by climate scientists and policy makers.
Concentrations of other greenhouse gases produced from human activities, such as methane and nitrous oxide, also reached records in 2014, the World Meteorological Organization announced in its annual Greenhouse Gas Bulletin. The report is one of several measurements made by different climate agencies to address the state of greenhouse gases.
“This evidence shows us that the concentrations are increasing, and they are increasing with increasing rates,” said Oksana Tarasova, chief of the W.M.O.’s Atmospheric Environment Research Division. “This calls for urgent and very strong actions to limit the emission of those greenhouse gasses.”
Hotter air can hold more moisture, which exacerbates greenhouse warming. According to Dr. Tarasova, if carbon dioxide levels reach 560 parts per million, or double their preindustrial levels, the feedback loop would cause water vapor and clouds to increase atmospheric warming to a rate that is three times as much as what the human-caused gases can do by themselves.
“We shouldn’t blame water vapor for making this place warmer,” she said. Rather, she said, by limiting the emissions of carbon dioxide, nitrous oxide and methane, people can balance the feedback loop and mitigate future warming.
The planet’s average surface temperature has risen about 1.8 degrees Fahrenheit (1.0 degree Celsius) since the late-19th century, a change largely driven by increased carbon dioxide and other human-made emissions into the atmosphere.
Most of the warming occurred in the past 35 years, with 15 of the 16 warmest years on record occurring since 2001. Last year was the first time the global average temperatures were 1 degree Celsius or more above the 1880-1899 average.
NASA’s analyses incorporate surface temperature measurements from 6,300 weather stations, ship- and buoy-based observations of sea surface temperatures, and temperature measurements from Antarctic research stations.