Andrea Leadsom, the new environment secretary, supports foxhunting and once said she wanted to end farming subsidies.

The pro-Brexit cabinet minister, who was Theresa May’s leadership rival before pulling out on Monday, was a surprise appointment to the Department for Environment, Food and Rural Affairs (Defra).

Leadsom’s new role has alarmed environmentalists, who highlighted her previous confusion about whether climate change is real and her support for a repeal of the hunting ban.

During her short leadership campaign, Leadsom pledged to hold a vote on bringing back foxhunting, saying it was “absolutely not proven to be in the interest of animal welfare whatsoever”. She said there was a “need to exterminate vermin, which foxes are” and called for a “proper, licensed regime”.

After becoming energy minister in 2015, Leadsom admitted having asked officials whether climate change was real.

“When I first came to this job one of my two questions was: ‘Is climate change real?’ and the other was ‘Is hydraulic fracturing safe?’ And on both of those questions, I am now completely persuaded,” she told the all-party parliamentary group on unconventional gas and oil in October last year.

However, since then she has repeatedly made it clear that decarbonising the energy supply is crucial and that this will not change after leaving the EU. “It is an essential responsibility that we hold towards our children and grandchildren, as the only way to effectively counter the threat of climate change,” she said this month.

Despite this assurance, Andrew Cooper, a Green party energy spokesman, said: “By appointing Andrea Leadsom – a woman who supports foxhunting and has consistently voted against measures to tackle climate change – as environment secretary, and scrapping the Department for Energy and Climate Change entirely, May appears to be sending a clear message that fighting climate change is simply not on her agenda.”

In her new job, Leadsom will have the task of devising a new system to allocate money for farmers that currently comes through the EU through the common agricultural policy (CAP).

During the campaign, she said cash for farmers should continue “in the short term whilst we think about what makes sense”, which may cause concern in the industry given their reliance on subsidies.

Leadsom hinted there should be wider a shakeup of the system, saying: “Some of the things that would make sense would be environmental trading credits, because at the moment you have farmers who have to do a bit of environmental planning and a bit of farming just to meet the EU requirements.

“It would make so much more sense if those with the big fields do the sheep, and those with the hill farms do the butterflies. That would make a lot more sense for the UK and it’s perfectly possible but only if we leave the EU and sort it out for ourselves.”

In 2007, Leadsom argued that “subsidies must be abolished” in an article on how to rejuvenate British farming.

Farmers currently get up to £3bn a year in EU subsidies through CAP, making up 55% of an average farmer’s income of around £20,000 in 2014.

Whatever British agricultural policy replaces CAP, Leadsom will have the task of working out a fair new system that protects farming livelihoods.