Earth is at its hottest in thousands of years. Here’s how we know.
Observations are enough to make scientists confident that the current period of warming is exceptional
The Washington Post, July 8, 2023
Observations from both satellites and the Earth’s surface are indisputable — the planet has warmed rapidly over the past 44 years. As far back as 1850, data from weather stations all over the globe make clear the Earth’s average temperature has been rising.
In recent days, as the Earth has reached its highest average temperatures in recorded history, scientists have made a bolder claim: It may well be warmer than any time in the last 125,000 years.
Tracing climatic fluctuations back centuries and millennia is less simple and precise than checking records from satellites or thermometers. It involves poring through everything from ancient diaries to lake bed sediments to tree trunk rings.
But the observations are enough to make paleoclimatologists, who study the Earth’s climate history, confident that the current decade of warming is exceptional relative to any period since before the last ice age, about 125,000 years ago.