The last 10 years were the hottest decade ever measured on Earth, last year was the second warmest ever and NASA says "you haven't seen anything yet."
The National Oceanic and Atmospheric Administration said Wednesday that the average global temperature in the 2010s was 14.7 degrees Celsius, with eight of the 10 hottest years ever recorded.
Parts of Africa, Asia, Australia, Europe and South America had record-high temperatures in 2019. Alaska's average temperature was above freezing for the first time in recorded history.
Many climate scientists who have seen the study said there was no other explanation for the record-breaking warming than human activity.
"This is going to be part of what we see every year until we stabilize greenhouse gases," said Gavin Schmidt, head of NASA's Goddard Institute for Space Studies. "We crossed over into more than 2 degrees Fahrenheit warming territory in 2015 and we are unlikely to go back. This shows that what's happening is persistent, not a fluke due to some weather phenomenon."
Experts say natural causes of a warmer atmosphere, including more heat from the sun and climate variations, are not big enough to explain the long-term temperature rise.
For those who still question global warming, the scientists say all one has to do is look at melting ice sheets, more powerful storms, floods in some parts of the world and drought in others as clear evidence.