- NOAA reported an average temperature for the year of 14.83 degrees C (58.69 degrees F) in 2016 – 1 degree C (1.69 degrees F) warmer than the average for the 20th century.
- NOAA also said that, at 10.15 square kilometers (3.92 million square miles), the Arctic’s sea ice level is the lowest it’s been since 1979.
- Weather- and climate-related disasters cost the U.S. 138 lives and $46 billion in 2016.
Once again, the planet set a record in 2016 for the warmest year yet since we started keeping track of global temperatures in 1880.
“We don’t expect record years every year, but the ongoing long-term warming trend is clear,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies in New York, in a statement.
Yet 2016 was the third in a string of years with record-high global temperatures.
To arrive at a global average temperature, NASA’s technique is based on a process worked out in the 1970s by NASA scientist James Hansen. Basically, researchers divide the earth up into a grid, including the oceans, and then they compare the anomalies – how much recorded temperatures differ from the averages – for each month. In some places, there might be cooler temperatures than what the records point to as typical, and in others, warmer ones.
Once they have these monthly average temperatures, they can then pull them together to look at the average global temperature for the year.
NOAA’s methods are different than NASA’s, but both agencies have corroborating evidence that our climate is heating up and we’ve got something to do with it.
In the ‘70s, Hansen and other scientists began noticing the warming, and through their analyses, they were able to tie that change in the climate to the release of carbon dioxide and other greenhouse gases that occurs when humans burn fossil fuels.
NASA scientists cautioned against looking at regional weather patterns as an indication of the overall trajectory of the climate. This year, for example, was only the fifth hottest ever for Australia.
Still, the long-term effects of global warming are apparent, as was clear from the extent of Arctic sea ice. At 10.15 million square kilometers (3.92 million square miles), the level is the lowest it’s been since 1979, based on NOAA’s data.
And the impacts are affecting our wallets. The U.S. experienced its second hottest year, and NOAA said that climate and weather disasters, such as droughts, wildfires, floods, and storms, killed 138 people and cost us $46 billion in 2016.
The monthly average temperatures from much of the year meant that its entry into the record books wasn’t surprising. El Nino, a sporadic set of weather changes in which the tropical Pacific Ocean warms, from 2015 carried over into the first few months of 2016. That led to eight months of record highs through August, according to NOAA’s calculations. And July was the hottest month ever recorded.
NOAA reported an average temperature for the year of 14.83 degrees C (58.69 degrees F) in 2016. That’s nearly 1 degree C (1.69 degrees F) more than the average for the 20th century and a 0.04-degree C (0.07-degree F) increase compared to 2015.
Looking back farther, it’s the fifth time this century that the global high temperature mark has been toppled. Scientists have also concluded that the earth has warmed up the most in the past 35 years, and all but one of the warmest recorded years have happened since 2001.
Though methodologies and data sources have changed and expanded since 1880, NASA researchers accounted for these differences and said they’re more than 95 percent certain that 2016 was the warmest year in the past 137 years.
- GISTEMP Team, 2017: GISS Surface Temperature Analysis (GISTEMP). NASA Goddard Institute for Space Studies. Dataset accessed 2017-01-23 at https://data.giss.nasa.gov/gistemp/.
- Hansen, J., R. Ruedy, M. Sato, and K. Lo, 2010: Global surface temperature change, Rev. Geophys., 48, RG4004, doi:10.1029/2010RG000345.
- NOAA National Centers for Environmental Information, State of the Climate: Global Analysis for Annual 2016, published online January 2017, retrieved on January 23, 2017 from http://www.ncdc.noaa.gov/sotc/global/201613.
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