In less than two weeks, 2016 will officially be the hottest year on the books in more than 120 years of record keeping by U.S. agencies.
It will be the third straight record-setting year — and of the 17 hottest years, 16 have been this century — a clear sign of the human-caused rise in global temperatures caused by the buildup of heat-trapping greenhouse gases over the past century. The world is already more than halfway down the road to surpassing the Paris climate pact goal to limit warming to less than 2°C (3.6°F) by 2100.
The running average of global temperatures throughout 2016 compared to recent years. Each month shows the average of that month's temperature and each month before it.
These milestones have climate scientists and policymakers concerned about keeping that goal, particularly as the incoming Trump administration will almost certainly be filled with cabinet members who reject the established science of climate change.
November was the second warmest on record (after November 2015), according to NASA data released last week, with an average temperature 1.71°F (0.95°C) above the 1951-1980 average.
The National Oceanic and Atmospheric Administration ranked the month slightly lower, in the fifth warmest spot, according to a report released Monday. It put the global temperature for the month at 1.31°F (0.72°C) above the 20th century average.
Each agency uses different baselines of comparison and processes global temperature data in slightly different ways, leading to small differences in the final numbers for particular months and years. Both, though, have shown clear agreement in overall warming trends, and expect 2016 to easily set the record in their respective datasets.For the year-to-date, 2016 is 1.69°F (0.94°C) above the 20th century average, according to NOAA, and 1.84°F (1.02°C) above the 1951-1980 average according to NASA.
While a very strong El Niño helped boost temperatures during this year and last, the record-setting temperature is mostly due to the long-term warming driven by human activities. Even years marked by El Niño’s cold counterpart, La Niña, are now warmer than El Niño years of previous decades because of this warming.
Last year, the world agreed to limit warming to no more than 2°C above pre-industrial levels by the end of this century and to try to keep it under 1.5°C. To show how close global temperatures already are to the second goal, Climate Central has been reanalyzing the monthly temperature data to compare it to a baseline closer to pre-industrial.
Averaging NASA and NOAA’s data, 2016’s temperature through November is 1.23°C (2.21°F) above the average from 1881-1910.
One major area of warmth during both November and the year as a whole was the Arctic. During November, the Arctic saw an almost unprecedented sea ice retreat, capping off a year that has shocked even seasoned Arctic researchers. The winter sea ice peak was the lowest on record (beating out 2015) and the summer minimum was the second lowest. Air temperatures in the region have continually been above average by double digits.
How temperatures around the world compared to normal for the year so far.
One reason NOAA’s global temperature for November may have been lower than NASA’s is that it doesn’t incorporate Arctic temperatures.
Another hotspot for November was North America; the contiguous United States is poised to have its second-hottest year on record.
Many climate scientists have expressed concern over some of President-elect Trump’s nominees to key cabinet posts, such as the departments of Energy and State. Rick Perry, the energy nominee, has dismissed the reality of climate change, and Rex Tillerson, nominee for secretary of state, is CEO of ExxonMobil, which spent decades ignoring its own scientists’ research tying fossil fuels to climate change.
There is concern that with these players, the incoming administration will roll back progress toward combating climate change, causing the world to charge past its goals of limiting warming.