Heavy rains from the Amazon to Australia have curbed sea level rise so far this century by shifting water from the oceans to land, according to a study that rejects theories that the slowdown is tied to a pause in global warming.

Sea level rise has been one of the clearest signs of climate change - water expands as it warms and parts of Greenland and Antarctica are thawing, along with glaciers from the Himalayas to the Alps.

But in a puzzle to climate scientists, the rate slowed to 2.4 millimetres a year from 2003 to 2011 from 3.4 mm from 1994-2002, heartening sceptics who doubt that deep cuts are needed in mankind's rising greenhouse gas emissions.

Writing in the journal Nature Climate Change on Sunday, experts said the rate from 2003-2011 would have been 3.3 mm a year when excluding natural shifts led by an unusually high number of La Nina weather events that cool the surface of the Pacific Ocean and cause more rain over land.

"There is no slowing in the rate of sea level rise" after accounting for the natural variations, lead author Anny Cazenave of the Laboratory for Studies in Geophysics and Spatial Oceanography in Toulouse, France, told Reuters.