Seal levels on the rise

Sea level rise, caused when ice melts and warmer water expands, appears to be accelerating, according to the latest data.

The average ocean level was 70 millimetres (2.75 inches) higher in 2015 than in 1993, having risen as much as 30 percent faster in the 10 years to 2015 than in the previous decade.

The pace is likely to pick up further as ice sheets and glaciers shed mass, threatening the homes and livelihoods of tens of millions of people in low-lying areas around the world.

The National Oceanic and Atmospheric Administration (NOAA) said in January the global average sea level could be between 0.3 and 2.5 metres (one foot to 8.2 feet) higher by 2100.

On current trends, meltwater just from the Antarctic ice sheet could contribute to a metre of lift, according to one study.