After a year of epic weather, drought, heatwaves, hurricanes and floods, America's intelligence establishment has come out with a bold new suggestion: maybe it's time the CIA stopped treating climate change as a secret.

A new report from the Defence Science Board – a US government agency – urges the CIA to step outside its traditional culture of secrecy and begin sharing the intelligence it has been gathering on climate change.

The report, Trends and Implications of Climate Change for National and International Security, goes as far as to recommend the establishment of a new agency devoted to the study of climate change – one that would operate in the open and transparent manner so alien to the CIA.

The report is the latest in the series of blows to CIA's climate centre, which has been struggling to justify its existence to the public since its establishment in 2009.

Republicans in Congress have derided the very notion of climate change as a national security threat, despite the Pentagon's view that it is a threat multiplier. Now it faces criticism that it has been hoarding data.

The report does not call for scrapping the CIA climate centre, but it does suggest that CIA's climate experts have been going about their business the wrong way.

The CIA's insistence on classifying the climate centre's reports have cut it off from university research on the cutting edge of climate science as well as other government agencies working on the issue, it said. "Compartmentalising climate change impact research can only hinder progress," the report said.

The CIA's secrecy on climate change has long irked other government agencies working in the same area. The climate centre last year turned down a freedom of information request for copies of its reports on climate impacts.

Although much of the data on climate change is gathered by satellites, the agency – citing the need to protect intelligence sources – said it was unable to release a single document. It declared the material "currently and properly classified".

Two analysts from the CIA climate centre did venture out to an off-the-record briefing with environmental groups earlier this year. But the analysts, who insisted they went unnamed, kept to generalities, a number of people at the briefing said.

Instead, a much more effective approach would be for the CIA climate centre to "make extensive use of open sources, seek to co-operate with other domestic and international intelligence efforts, and report most of its products broadly within governmental and non-governmental communities, the report said.

It went on to propose that the CIA climate centre produce an analysis of global hotspots where climate change and water supply was destabilising government and economies.

Then, crucially, it proposed the CIA should share that information.