LONDON: British public conviction about the threat of climate change has declined sharply after months of questions over the science and growing disillusionment with government action, a leading poll has found.

The proportion of British adults who believe climate change is ''definitely'' a reality has dropped from 44 per cent to 31 per cent in the past year, according to the latest survey by Ipsos Mori.

Overall, about nine in 10 people questioned still appear to accept that some degree of global warming is happening.

But the steep drop in those who have no doubts may mean it will be harder to persuade the public to support action to curb the problem, particularly with higher prices for energy and other goods.

The poll also found a significant drop in those who said climate change was caused by human activities. A year ago this number was one in three, but this year just one in five people believed global warming to be caused by people, according to Edward Langley, Ipsos Mori's head of environment research.