Researchers say they have uncovered the climate system's "missing heat" and, in so doing, have punched a hole in the argument that global warming has slowed during the last 15 or so years.

Following decades of a steady, upward march, global temperatures suddenly stagnated back in the late 1990s. However, the study notes, climate records are based on observational data that only accounts for 84 percent of the planet. The Polar regions and Africa are largely excluded, the researchers write in the Quarterly Journal of the Royal Meteorological Society.

Realizing this, University of York computational scientist Kevin Cowtan teamed up with Robert Way, a cryosphere specialist and Ph.D. student at the University of Ottawa. Together they gathered satellite observations and surface data derived from weather stations and ships in these unstudied regions.

The missing heat, the results suggest, has been there all along -- hiding out in these unsampled parts of the world. The Arctic alone is warming some eight times faster than the rest of the planet, according to the study.

By plugging these and other observations into overall trends, researchers found that the rate of warming since 1997 is in fact two and a half times greater than previous estimates.

"There's a perception that global warming has stopped but, in fact, our data suggests otherwise," Cowtan said in a statement. "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."

According to Way, these findings help explain the continued trends of sea ice loss that have led to an increased rise in sea levels.

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