Concern around the issue now stands at the highest level since the Cop26 conference in Glasgow in November 2021, says Ipsos.
The public’s concern about climate change and the environment has seen a sharp jump this summer.
One in four Britons (25%) see the environment as an important issue for the country, up by 13 percentage points since July, the latest Ipsos Issues Index suggests.
Concern around the issue now stands at the highest level since the Cop26 conference in Glasgow in November 2021.
It also now ranks joint third with the NHS, which saw a drop of eight percentage points since July.
The findings come after extreme temperatures, wildfires and ocean warming across the world hit headlines in July.
The Government also recently signalled a softening of green policies due to cost pressures facing households, prompting a backlash among MPs, environmental groups and scientists.
The Ipsos Issues Index, which is conducted monthly, gathered the opinions of 1,004 adults across Great Britain between August 2 and 7.
It found that the economy and inflation remain the two biggest issues with 37% of Britons mentioning each.
The proportion of people mentioning the economy rose by seven percentage points since last month, with almost a quarter (23%) seeing it as the single most important national concern.
Meanwhile, concern about immigration is at its highest level since 2017, hitting 23% after a two percentage point jump since July.
Significant differences on the issue remain among different groups, with Conservative supporters (36%) and those aged over 65 (30%) more likely to mention it, compared with Labour supporters (11%) and those aged 18-34 (14%).
Mike Clemence, a researcher at Ipsos, said: “Climate change and the environment has risen to become seen as the joint-third biggest issue facing the country this month, and news reports about wildfires and extreme temperatures disrupting holidays are a likely cause.
“Elsewhere we see a small rise in concern about immigration, with worry strongly centred among Conservative party supporters and older people.
“However, economic issues continue to lead public concern, with worry about the state of the economy rising this month, particularly for Labour party supporters and the middle classes.”
Last month, Downing Street made clear that ministers are scrutinising existing net zero pledges “in light of some of the cost-of-living challenges”, citing the potential for technological advances.
Rishi Sunak also confirmed Government support for around 100 new licences for oil and gas extraction in the North Sea.
He has insisted that granting the licences is “entirely consistent” with the UK’s commitments on net zero, despite campaigners calling it “wrongheaded”.