Warm summer temperatures may not melt the Greenland ice sheet as fast as previously feared and may actually slow the flow of glaciers, British researchers say.

Scientists at the University of Leeds say they believe increased melting in warmer years causes the internal drainage system of the ice sheet to adapt and accommodate more melt-water without speeding up the flow of ice toward the oceans, a university release said Wednesday.

The Greenland ice sheet covers roughly 80 percent of the island and contains enough water to raise sea levels by 22 feet if it were to melt completely.

Rising temperatures in the Arctic in recent years have caused the ice sheet to shrink, prompting fears that it may be close to a tipping point of no return.

The Leeds researchers used satellite observations of six landlocked glaciers in southwest Greenland to study how ice flow develops in years of markedly different melting.

"It had been thought that more surface melting would cause the ice sheet to speed up and retreat faster, but our study suggests that the opposite could in fact be true," Professor Andrew Shepherd from the university's School of Earth and Environment said. "If that's the case, increases in surface melting expected over the 21st century may have no affect on the rate of ice loss through flow.

"However, this doesn't mean that the ice sheet is safe from climate change, because the impact of ocean-driven melting remains uncertain," he said.