EXPLAINED IN 76 SECONDS
WHAT IT IS
Temperature records go back over 130 years and show that the earth’s average temperature has been rising for more than a century. Temperature measurements are taken by both land and sea all over the world by several international organizations. Groups like NASA, NOAA, and the UK Met Office keep and manage their own temperature data, but they all show the same thing: the earth is warming. Overall, the planet has warmed about 1.6°F since the 1880s, and the 10 warmest years on record have all occurred since 1998. That includes 2014, which was the hottest single year on record.
WHY IT'S IMPORTANT
The rise in global temperature is the clearest single indicator of climate change. The fact that all three major dataset corroborate each other despite differences in analysis only strengthens confidence in what they show. Though 1.6°F might not sound like a big number, it has already contributed to an array of issues from melting Arctic sea ice to rising seas to shifting ecosystems, droughts and heat waves. Since the 1950s, each decade has been warmer than the last including a big jump after the 1970s. Temperatures are expected to rise even more steeply in the coming decades unless greenhouse gas emissions are curbed.