THIS ARTICLE IS republished from The Conversation under a Creative Commons license.
In the past week, Earth’s record for the hottest day was broken twice. Sunday, July 21, was declared Earth’s hottest day since records began, when average surface temperature reached 17.09 degrees Celsius. On Monday the record was broken again, when average temperatures reached 17.16 degrees Celsius—and Tuesday was almost as hot.
The declarations were made by Copernicus, the European climate change service. They made international headlines—especially in the northern hemisphere, which has been experiencing extreme summer heat.
Determining the global average temperature