UK spy chiefs warned government ministers of the catastrophic impacts on national security from the collapse of vital ecosystems around the world, driven by the climate crisis and the overexploitation of nature. But their report, which was supposed to be published almost a year ago, was suppressed under Keir Starmer. Now the government is briefing foreign ministers from other countries on the findings with a view to gathering global support for more concerted action on the risks.

What is the report? In the first report of its kind, the UK’s spy chiefs set out stark warnings of the catastrophic risks to the UK from the collapse of vital ecosystems around the world, driven by the climate crisis and our failures to protect nature The Guardian has seen part of the report and has spoken to a large number of people familiar with its contents, which warn of food shortages, conflicts, mass migration and other threats to the UK’s national security, including going as far as the risk of nuclear war or the breakdown of society. These threats are not regarded as some far-off or remote contingency: disastrous impacts, for instance on the UK’s food supply, could be expected as soon as 2030, it warns.

What did they find? The report, which was originally commissioned under the previous Tory government, looked at the potential consequences of a range of scenarios such as the collapse of the Amazon rainforest, which scientists have warned could be close to switching from a rainforest to a savannah-like system under the impact of heating and deforestation The authors found these could result in food shortages in the UK, which imports about 40% of its food. The report also reviewed the development of new pandemics from areas deforested and overexploited, border disputes among countries affected by the climate crisis, increased Russian and Chinese influence over critical mineral supply chains, and civil tensions within the UK as these impacts play out.

Collapsing ecosystems overseas – the Congo basin was also a focus – could result in mass migration as people are forced to leave areas no longer habitable, triggering potential unrest and “more polarised and populist politics in the UK and its allies”, along with “more strain on national infrastructure”, and conflict could result from countries fighting over scarce food supplies. While the risk of nuclear war is still regarded as small, it is a potential impact.

One person who had seen the whole report described it to the Guardian as “apocalyptic”. How was the report suppressed?

The report was supposed to be published in full last October before the Cop30 climate summit in held in Belém, in the Brazilian Amazon But Downing Street officials intervened at the last moment to prevent its publication. The Guardian revealed the report’s key findings at the time through leaks, as subsequently did other media, but nothing was officially forthcoming until January, when, after several refused attempts under the Freedom of Information Act, a partial summary of parts of the report was released to the Green Alliance thinktank We’ve been reading for years about the impacts of the climate and biodiversity crises – what is different about this?

The report was supposed to be published in full last October before the Cop30 climate summit in held in Belém, in the Brazilian Amazon But Downing Street officials intervened at the last moment to prevent its publication. The Guardian revealed the report’s key findings at the time through leaks, as subsequently did other media, but nothing was officially forthcoming until January, when, after several refused attempts under the Freedom of Information Act, a partial summary of parts of the report was released to the Green Alliance thinktank We’ve been reading for years about the impacts of the climate and biodiversity crises – what is different about this?

Scientists have issued numerous stark warnings of a future of droughts, floods, storms and severe heatwaves if global heating exceeds 1.5C above preindustrial levels.

This report is different, however, because it comes from the UK’s joint intelligence committee, the cross-government ministerial advisory body that oversees the work of the UK’s spy agencies and is tasked with monitoring national security. It examined the climate and nature crises for their potential to damage the UK’s security and defence, and found the UK underprepared for the impacts. What has the government done about these risks?

The government has not issued a formal response. The fact that the report has not been published means ministers can hide from its implications, according to Adrian Ramsay, the Green party MP for Waveney Valley, who has called repeatedly for its publication and led a parliamentary debate on it earlier this year. A parliamentary committee has also tried to persuade ministers to disclose the findings, and their response to them. Moreover, while the report warns of what will happen if ecosystems break down, the UK has slashed its overseas development aid hurting the vulnerable countries where many of these ecosystems are located. International climate finance has been reduced from £11.6bn in total over the five years 2021 to 2026, to about £2bn a year for the next two years, and the previous ringfencing of spending on nature and forests within that budget has been dropped. Many nature conservation projects in vulnerable countries were among those cut the Guardian previously revealed.

Moreover, while the report warns of what will happen if ecosystems break down, the UK has slashed its overseas development aid hurting the vulnerable countries where many of these ecosystems are located. International climate finance has been reduced from £11.6bn in total over the five years 2021 to 2026, to about £2bn a year for the next two years, and the previous ringfencing of spending on nature and forests within that budget has been dropped. Many nature conservation projects in vulnerable countries were among those cut the Guardian previously revealed.

However, this week the government has taken the first steps towards acting on the report’s findings, under the guidance of the foreign secretary, and former energy and climate secretary, Ed Miliband, with the backing of the prime minister, Andy Burnham. What has he done? On Wednesday, Miliband led a briefing about the report’s findings to foreign ministries from around the world including those of the EU, Kenya and Australia, which is in charge of the negotiations at the next UN climate summit, Cop31 in November Ministers were not given full copies of the report at the closed-door meeting at the UN general assembly in New York, but were given verbal summaries of its findings.

What impact will this have? Miliband, who told the Guardian he would put the climate at the heart of foreign policy also announced £330m for the Global Environment Fund (GEF), one of the principal vehicles for funding nature protection in the developing world. The UK will also provide £400m for Brazil’s Tropical Forests Forever Facility (TFFF).

Jonathan Hall, managing director of Conservation International UK, told the Guardian: “The Starmer administration’s decision to drop the longstanding precedent to spend a significant proportion of our international climate aid on nature and forests was totally unjustified. This [spending] is both scientifically essential and very popular with the UK public, according to polling, so Miliband now needs to build on the contributions to the TFFF and GEF and reintroduce a clear target for at least a third of UK climate aid to be dedicated to natural ecosystems and tropical forests.”