Carbon dioxide, or CO2, is by far the most important greenhouse gas in both total amount and rate of increase, and is responsible for 80 percent of the increased warming influence captured by the AGGI since 1990.
The globally averaged annual temperature during 2017 was third-warmest in NOAA’s 138-year global temperature record, behind 2016 and 2015.
Record 2017 warmth was observed across parts of the western and central Pacific Ocean, western Indian Ocean, southern South America, and the southwestern contiguous U.S. and scattered across parts of the northern Atlantic Ocean, Africa, the Middle East, and eastern Asia.
The five warmest years on record for the contiguous U.S. have all occurred since 2006.