Climate scientists harbour strong scepticism over whether governments will markedly slow down global warming despite pledges by leaders, a survey by the international science journal Nature has found.

Their concerns over global warming have even caused sections of climate scientists to reconsider their major life decisions such as where to live or whether to have children, the anonymous survey has also revealed.

The survey results, published by the journal on Monday coincide with a summit of world leaders featuring the heads of state of more than 100 countries at the climate conference in Glasgow. Prime Minister Narendra Modi is scheduled to speak at the summit alongside heads of state of Australia, European Union, Canada, Germany and the US.

The survey is based on responses from 92 of 233 researchers across the world who had earlier this year authored a report for the Inter governmental Panel on Climate Change that called for urgent actions to curb global warming.

But 60 per cent of the survey’s respondents expect the world will warm to 3°C by the end of the century, crossing the 1.52°C temperature rise cap required to avert the most devastating impacts of climate change.

Around 88 per cent of respondents believe global warming already represents a crisis and 82 per cent believe they will observe catastrophic experiences of climate change in their own lifetimes.

Four in 10 respondents said global warming had caused either them or scientists they know to reconsider decisions on where to live, while 17 per cent said concerns about global warming had prompted them to rethink whether to have children.

“The pessimism expressed by some IPCC panelists underscores the vast gulf between hopes and expectations for the climate summit … in Glasgow,” the journal Nature said amid analyses indicating that current pledges by countries worldwide are not enough to cap warming at 2°C or below.

A report from the United Nations Environmental Programme had last week warned that climate pledges already made by nations ahead of the Glasgow summit would place the world on course to a 2.7°C temperature rise.

The world’s major economies agreed at a group of 20 (G20) summit on Sunday to stop international financing of coalfired power plants and committed to revisit and further enhance their emissionsreduction targets “where necessary”.

But climate policy analysts said the language in the G20 communique on other things such as netzero emission targets and finance to help developing countries in cutting emissions was muddled. Some environmental groups also expressed disappointment that the G20 meeting did not commit to phase out domestic coal use.

“G20 countries deserve credit for sending an unequivocal message that they will stop financing unabated coal power abroad, yet they failed to make the obvious leap to stop building coalfired plans at home as well,” Helen Mountford, vicepresident for climate and economies at the World Resources Institute, an environmental think tank said in a statement.