Five different organizations that track temperatures have all come to this conclusion: 2018 ranked among the five warmest years on record, landing in fourth place.
All of them - NOAA, NASA, Berkeley Earth, the United Kingdom's Hadley Centre and the Japan Meteorological Agency - crunched the numbers using different methods, but they each arrived at the same answer.
Confidence in this ranking is, thus, very high.
The past five years have each now ranked among the five warmest on record. According to NASA, 18 of the 19 warmest years have occurred since 2000.
The warming of the planet is unambiguous and irrefutable.
1) Temperature differences from normal around the globe averaged over the last five years
If the top image doesn't make this clear, which shows the temperature differences from normal averaged over the last five years, here are four more...
2) A mountain of warming evidence
This chart from NASA shows the temperature difference from normal, year by year. And the tendency is for years to keep climbing higher and higher.
Here's a similar presentation from the U.K. Hadley Centre:
2018 to be nominally the 4th warmest year on record globally, at 0.91±0.1°C above the long-term pre-industrial average. This means that the last four years have been the warmest on record. https://t.co/kYXYmq98qv pic.twitter.com/tpozlvmok7— Met Office (@metoffice) February 6, 2019
3) Five data sets, the same signal
The five research institutions mentioned earlier analyze land and ocean temperatures from all over the planet.
While they use different techniques for processing the data, the resulting trends hardly differ. All of them show roughly the same, unmistakable warming signal.
"Though there are minor variations from year to year, all five temperature records show peaks and valleys in sync with each other," NASA's Earth Observatory reports.
"All show rapid warming in the past few decades, and all show the past decade has been the warmest."
4) 42 straight years of above-average global temperatures
According to NOAA's analysis, 2018 marked the 42nd year in a row of temperatures warmer than the 20th-century average - dating back to 1977.
"Nine of the 10 warmest years have occurred since 2005, with the last five years comprising the five hottest," it noted.
5) Red is overwhelming blue
The past 5 years have been the warmest such period on record since at last 1880, NASA&NOAA have found. 2018 ranks as world's 4th warmest year, with 9/10 warmest years occurring since 2005. https://t.co/oX5UUtDG9s pic.twitter.com/liW55pUbCJ— Andrew Freedman (@afreedma) February 6, 2019
Axios created the above visual, which shows temperature differences from average around the globe during the periods centered on the 1940s and more recent decades. The contrast is stark and startling.
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