Expert Comment: Is nature really a security issue?

In January 2026, the UK Government published a ground-breaking national security assessment. For the first time, the Joint Intelligence Committee had assessed the risks to the UK from global biodiversity loss. The conclusions were stark – biodiversity loss is a significant threat to national security, with six critical global ecosystems at risk of collapse between 2030 and 2050, threatening food, water and climate systems. 

Although the report was only released (in a redacted version) following a freedom of information request, a change in government has raised the issue up the agenda. The current Foreign Secretary, Ed Miliband presented the findings to a group of UN foreign ministers, resulting in a joint statement that they “regard the climate and nature crisis as a national and global security threat”.

But what exactly are the links between nature loss and security, and how can they be addressed? We investigated this through an intensive nine-month research “sprint” as part of the Agile Initiative at the Oxford Martin School.

Sprints are fast-paced projects that address urgent policy questions. Crucially, we work directly and collaboratively with stakeholders to address their priorities and inform policy development. In this case, the sprint involved 35 Oxford researchers and over 60 policy officials and practitioners from 14 UK government departments, statutory bodies and military services. 

We found that while climate security risks were recognised across parts of government, there was far less understanding – and indeed some scepticism - of the risks from nature loss. So we developed evidence chains mapping how biodiversity links to human and national security for a selection of critical natural systems. 

First, we looked at how tropical forests and ocean ecosystems support climate, water and food security. Half of all carbon dioxide emissions either dissolve into the sea or are taken up by land-based ecosystems, especially tropical forests. But rainforests also recycle rainfall into huge “aerial rivers” of clouds and water vapour, which sustain the forest itself and surrounding regions. For example, the Amazon rainforest generates rain across the huge La Plata basin to the south which produces most of South America’s crops (including 18% of the UK’s soybeans, used to feed livestock). However, the Amazon has been 17% deforested, and models suggest it could pass a tipping point at 22%, where it transforms to dry savanna.

Continued forest degradation will release stored carbon and reduce carbon dioxide absorption, trapping more heat in the air and pushing the climate system closer to tipping points. Permafrost and ice-sheets will melt faster, and ocean circulation could slow down, potentially shutting down the Gulf Stream that brings warm water from the tropics. This could lead to much colder, drier winters in northern Europe. Globally, impacts on rainfall could cut the area of cropland suitable for growing wheat and maize by half, and most of the UK could become unsuitable for arable crops.

In parallel, pressures on ocean ecosystems (pollution, overfishing and climate change) could weaken the “biological carbon pump” in which plankton and other marine life absorb carbon from the air, which is released hundreds of years later after circulating in deep ocean currents. This system is currently at equilibrium, but if marine life declines there is a risk that not enough carbon will be absorbed to balance the amount being released. This issue is complex and needs more research, but as the ocean stores 85% of all carbon it represents a big unknown risk.

Risks to food production are compounded by the global decline in wild pollinators and natural pest predators, driven by habitat loss, pesticide over-use and competition from managed honeybee colonies. Wild pollinators and pest predators support production of fruit, vegetable and oilseed crops that are essential for nutrition and health, as well as economically and culturally important crops like coffee and cocoa.

The UK is exposed to these cascading risks to climate, food and water security both at home and through our dependence on imports. At home, 59% of UK grade one farmland is at risk of flooding by 2050, and much of the rest is at risk of water scarcity. But we also import 40% of our food (mostly by sea, and shipping is also highly vulnerable to climate risks). 

Risks to food and water security overseas don’t only affect UK imports – they can drive geopolitical instability and conflict over resources, undermine confidence in governments, and create more opportunities for vulnerable people to be exploited by criminal and terrorist groups – all with implications for UK security. There is also a growing global risk from the weaponisation of nature, with conflict actors attacking the environment to inflict trauma on communities. 

The most vulnerable countries need support to protect their natural systems and adapt to the increasing impacts of climate change and nature loss, helping to, for example, reduce internal and cross-border environment-driven displacement. The UK can, and should, show global leadership on these issues through strong domestic and diplomatic action.

The evidence we compiled paints a compelling picture of the urgent need to protect and restore critical natural systems both in the UK and overseas. This includes protecting the birds, mammals and insects that disperse seeds and pollinate wild plants, and reducing stresses such as pollution, hunting and overfishing.

Demand management is a key lever for change. Greater action is needed to save energy and water and shift to healthier and more plant-based diets, in order to reduce impacts on climate and nature and reduce the severity of supply and price shocks. Reducing reliance on fossil fuels is crucial to limit climate change and protect energy security. 

We also need to invest in societal resilience. Environmental stress from heatwaves, floods, pollution and nature loss erodes the mental, social, and economic capital that provides community cohesion and resilience to shocks. Resilient societies can absorb information on adaptation options more effectively, recover faster, and govern nature better. Protecting and enhancing accessible nature-rich urban green space is vital for adapting to climate change and boosting physical and mental health.

While there is already enough evidence of the need for urgent action, our forward-looking research agenda outlines priority evidence gaps alongside a list of potential interventions and behavioural science insights. Ultimately, with strong, effective, accountable, equitable and inclusive governance we can shift from cascading risks to cascading benefits for nature and people alike. The national and human security risks of not responding are immense.

The report ‘The role of critical natural infrastructure in supporting national security’ is available here.