The world will warm by at least 3C by the end of the century, some UN Intergovernmental Panel on Climate Change (IPCC) scientists have warned.
Nearly two thirds of those who responded to a Nature survey of IPCC authors said that they expect the planet to warm by this much.
However, some said the world might meet the target of limiting warming to 1.5C.
The survey, featuring answers from around 40% of the group of 92 scientists, indicates scepticism that governments will markedly slow the pace of global warming.
This is despite promises made by global leaders in the 2015 Paris climate agreement.
The UN scientists’ findings come as the Cop26 climate summit begins in Glasgow.
Released in August, the latest IPCC climate-science report, approved by 195 governments, concluded that fossil fuel emissions are driving planetary changes, threatening people and the ecosystems humans rely on for food and other resources.
The Nature journal conducted an anonymous survey of 233 authors who are part of the IPCC working group.
The 92 scientists who took part did so in a personal capacity, not as representatives of the IPCC.
Sixty per cent of respondents said they expect the world will warm by at least 3C by the end of the century, relative to pre-industrial times.
And 88% said they think the world is experiencing a ‘climate crisis’, while nearly as many said they expected to see catastrophic impacts of climate change in their lifetimes.
More than two fifths (41%) said global warming has caused them to reconsider major life decisions, such as where to live, and 17% said it had made them think again about whether to have children.
While more than three fifths (61%) said they experience anxiety, grief or other distress because of concerns over climate change.
But the survey also had some more positive responses.
More than 20% of the scientists said they expect nations to limit global warming to 2C or less, and 4% said the world may meet the target of limiting warming to 1.5C.
The survey is reported in a feature in Nature.