British and Canadian researchers say "missing heat" in the climate system casts doubt on suggestions global warming has slowed or stopped in the past decade.

Kevin Cowtan, a computational scientist at the University of York, and Robert Way, a cryosphere specialist at the University of Ottawa, say observational data on which climate records are based cover only 84 percent of the planet, with the polar regions and parts of Africa largely ignored.

They have reconstructed the "missing" global temperatures using a combination of observations from satellites and surface data from weather stations and ships on the peripheries of the unsampled regions, the University of York reported Wednesday.

One of their finding is that the arctic is warming at about eight times the pace of the rest of the planet, they said.

"Changes in arctic sea ice and glaciers over the past decade clearly support the results of our study," Way said. "By producing a truly global temperature record, we aim to better understand the drivers of recent climate change."

While previous studies, which have only covered about five-sixths of the globe, suggest global warming has slowed substantially since 1997, the addition of the "missing" data indicates the rate of warming since 1997 has been two and a half times greater than those studies yielded, the researchers said.

"There's a perception that global warming has stopped but, in fact, our data suggests otherwise," Cowtan said. "But the reality is that 16 years is too short a period to draw a reliable conclusion. We find only weak evidence of any change in the rate of global warming."