Temperatures have not risen as fast as they are now in the 11,300 years that the US researchers studied and climate models showed that by the end of this century, temperatures would be warmer than anytime since the last ice age, they said in the journal Science.
Their data - compiled by studying such things as ice cores, fossils and ocean sentiment - looked back over a much longer era than previous research, which went back 1,500 years.
The research, led by Shaun Marcott at Oregon State University, prompted concerns about how and if humans and other species would be able to adapt to the rapid temperature rise.
"We and other living things can adapt to slower changes," climate expert Michael Mann of Pennsylvania State University told The NewYork Times.
"It's the unprecedented speed with which we're changing the climate that is so worrisome."