Meltwater is streaming across the ice sheet in Greenland, seen here on Wednesday, December 5, 2018. Greenland's ice sheet is melting at a rate "off the charts" compared with the previous four centuries, warns a new study. Researchers have said that if this melting continues at "unprecedented rates", which they attribute to warmer summers, it could accelerate the already rapid pace of sea level rises. [Photo: VCG]"

Meltwater is streaming across the ice sheet in Greenland, seen here on Wednesday, December 5, 2018. Greenland's ice sheet is melting at a rate "off the charts" compared with the previous four centuries, warns a new study. Researchers have said that if this melting continues at "unprecedented rates", which they attribute to warmer summers, it could accelerate the already rapid pace of sea level rises. [Photo: VCG]"

Meltwater is streaming across the ice sheet in Greenland, seen here on Wednesday, December 5, 2018. Greenland's ice sheet is melting at a rate "off the charts" compared with the previous four centuries, warns a new study. Researchers have said that if this melting continues at "unprecedented rates", which they attribute to warmer summers, it could accelerate the already rapid pace of sea level rises. [Photo: VCG]"

Meltwater is streaming across the ice sheet in Greenland, seen here on Wednesday, December 5, 2018. Greenland's ice sheet is melting at a rate "off the charts" compared with the previous four centuries, warns a new study. Researchers have said that if this melting continues at "unprecedented rates", which they attribute to warmer summers, it could accelerate the already rapid pace of sea level rises. [Photo: VCG]"