LONDON (Thomson Reuters Foundation) - A majority of Britons think climate change will be a more important issue than Brexit in the future, a poll showed on Friday, a day after the country sweated in a heatwave, hitting its highest temperature for July.

British Prime Minister Boris Johnson took office on Wednesday vowing to implement the result of the 2016 Brexit referendum and lead Britain out of the European Union on Oct. 31 with “no ifs or buts”.

Yet despite a flurry of headlines on the perils of leaving without a deal, seven in 10 British adults believe climate change matters more in the long term than quitting the EU, said the survey, commissioned by British charity Christian Aid.

Two-thirds of the 2,072 people surveyed between July 19 and 21 by research firm ComRes said Johnson should prioritise climate change in his role as leader.

Britons are “waking up to the devastating effects of the climate emergency”, even in a time of political turmoil, Laura Taylor, Christian Aid’s advocacy director, said in a statement.

“UK adults know there is a bigger crisis, which is potentially catastrophic for the whole of humanity,” she said.

Johnson has a mixed record on climate action.

As mayor of London, he shrank the city’s congestion charge zone, a move counter to efforts to curb carbon emissions and air pollution, but he encouraged cycling by rolling out a public bike-hire scheme.

Johnson came out against the expansion of Britain’s largest airport, Heathrow, while serving as foreign secretary, though ultimately missed a key vote to block it.

Alok Sharma was appointed on Wednesday as Britain’s new cabinet minister for international development, a key role in shaping the country’s climate policy overseas.

He said in a statement that Britain’s aid budget, which accounts for 0.7% of gross national income, would be used to combat climate change alongside other global challenges, such as diseases and humanitarian disasters, but did not give details.

“People genuinely are concerned about climate change because Brexit will be sorted, one way or the other, in due course,” said Simon Gill, acting executive director of the Overseas Development Institute, a London-based think-tank.

“Climate change is much more intractable and needs much more coherent... action worldwide – and that’s more challenging,” he told the Thomson Reuters Foundation.

Climate change should be central to everything Britain’s Department for International Development does, said Gill, pointing to the especially high risks facing the poorest countries and small island states.

“There are development gains which could be reversed if we don’t address and do sensible things around climate,” Gill said.

David Westwood, director of policy and programmes at charity World Vision UK, said Britain’s overseas aid was a key part of building the country’s influence on the global stage, while helping ensure peace and stability, and tackling poverty.

“It is crucial that (Sharma) maintains the 0.7% aid budget, and puts a focus on the causes of humanitarian emergencies such as conflict and the climate crisis,” he said in a statement.