Average world temperatures are on course to far exceed the main goal set in the 2015 Paris Agreement on limiting global warming, a study showed on Tuesday.

But the overshoot by the end of this century could be less severe than expected thanks to significant efforts by some countries to combat climate change, said the report by Climate Action Tracker (CAT), a consortium of three independent European research groups.

The Paris Agreement aims to restrict warming to "well below" 2°C above pre-industrial times.

Countries are meeting in Poland from December 2-14 to agree guidelines for implementing the pact which comes into force in 2020 but there are concerns these will be too weak to limit temperature rise to within safe levels.

The CAT report said there had been progress since 2015, but current policies meant the world was heading for warming of 3.3°C.

That compared with the 3.4°C it predicted a year ago, and it said that if governments were to implement policies they had in the pipeline, warming by 2100 could be limited to 3°C.

Even a rise of 3°C could cause loss of tropical coral reefs, Alpine glaciers, Arctic summer sea ice and perhaps an irreversible melt of Greenland's ice which would drive up world sea levels, a United Nations science panel has said.

The UN Intergovernmental Panel on Climate Change (IPCC) said in October that keeping the rise to 1.5°C was possible but would require rapid and unprecedented changes in human behaviour.

"We have yet to see this translate into action in terms of what governments are prepared to put on the table," said Bill Hare, chief executive of Climate Analytics, one of the three CAT research groups.

Since the Paris accord was agreed, countries including Argentina, Canada, Chile and India plus the European Union are moving in the right direction towards cutting emissions.

Countries such as Norway and Costa Rica are making progress with low-carbon transport and renewable energy deployment but China's carbon emissions rose again this year, the report said.

"With prices for renewables dropping roughly a third since Paris, both South Africa and Chile are mapping out strategies to address coal, and renewables are taking off in India,” said Niklas Höhne of research group NewClimate Institute.

But countries including the United States, Australia, Brazil, Indonesia, Russia and the United Arab Emirates have made either no progress or taken backward steps.