Scientists have accused the US Environmental Protection Agency of distributing misleading statements about climate change, following the leaking of an internal email advising agency staff to downplay the certainty of the science.

The email, issued by the EPA’s Office of Public Affairs (OPA) and sent out to communications directors and regional public affairs directors, was forwarded to others and shared throughout the agency. The email acknowledges that communities face “challenges” in dealing with the consequences of climate change.

However, the email, obtained by HuffPost, also sets out ambiguous talking points favoured by Pruitt, such as: “Human activity impacts our changing climate in some manner. The ability to measure with precision the degree and extent of that impact, and what to do about it, are subject to continuing debate and dialogue.”

The email adds that “while there has been extensive research and a host of published reports on climate change, clear gaps remain including our understanding of the role of human activity and what we can do about it”.

Joel Scheraga, senior climate adaptation adviser to the agency administrator, Scott Pruitt, was one person to forward the email, which states Pruitt encourages an “open, transparent debate on climate science”.

An EPA spokeswoman said the points were “developed by the office of public affairs. The agency’s work on climate adaptation continues under the leadership of Dr Scheraga.”

Since becoming EPA head under Donald Trump, Pruitt has erroneously denied that carbon dioxide is a “primary contributor” to warming that has seen the Earth’s average temperature increase by about 1C (1.8F) over the past century. Pruitt has also said industrialization has warmed the planet “to a certain degree” but that “humans have most flourished during times of warming trends”.

During his tenure, the EPA has removed information on its website about climate change, scrapped a climate adaptation program and advocated the need for “regulatory certainty” by loosening emissions regulations for vehicles and the fossil fuels industry. A televised “red team, blue team” debate between climate scientists and those who reject the science has also been mulled.

Pruitt was a vocal supporter of Trump’s decision to remove the US from the Paris climate agreement and is busy dismantling the Obama administration’s clean power plan, which Pruitt fought in court when attorney general of Oklahoma.

Scientists have pointed out that while the exact ramifications of climate change are yet to play out, the science behind it is well established and points directly to human culpability. A major report released by government scientists last year reiterated that humans are the “dominant” driver of global warming, with it being “highly likely” that the release of greenhouse gas emissions has caused more than half of all warming since 1951.

The email forwarded by Scheraga is “literally true but carefully crafted to mislead”, according to Andrew Dessler, a climate scientist at Texas A&M University.

“There is uncertainty in climate science, but the uncertainty spans the range of climate change being somewhat serious to extremely serious,” he said.

Dessler said any gaps on scientists’ understanding are not big enough to declare climate change a “non-problem”. He added: “And what we can do about it is quite clear: to stabilize the climate, we need to reduce emissions of greenhouse gases to near zero.”

Kerry Emanuel, a meteorologist and climate scientist at the Massachusetts Institute of Technology, said: “If confronting serious risks depended on first converting risks to certainties, no one would get flu shots, there would be no attempt to reduce stockpiles of nuclear weapons and businesses would fail at a high rate, having made no efforts to mitigate their risks.

“Mr Pruitt is engaged in a disingenuous effort to stall measures to mitigate climate risk under the false pretext of concern about uncertainty.”

The leak comes as it was revealed that Pruitt, already under fire over his use of first class air travel, lived last year in a Washington DC house co-owned by the wife of a leading energy lobbyist.

Property records obtained by ABC News show that Pruitt lived in a townhouse partly owned by Vicki Hart, the wife of Steven Hart, chief executive of lobbying firm Williams and Jensen. Hart’s clients include the NRA and gas company Cheniere Energy.

“Pruitt’s corruption knows no bounds and he should be fired immediately,” said Michael Brune, executive director of the Sierra Club, one of a coalition of environment groups who have demanded Pruitt be removed from his position.