Alison Smith, a Senior Research Associate in the Ecosystems Group at the Environmental Change Institute, and Dr Timothy Clack, Associate Professor and Director of the Climate Change & (In)Security Programme, explain why halting nature and biodiversity loss is imperative to safeguard UK national security.

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.

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.

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.

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).

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.

Alison Smith and Dr Timothy Clack

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.

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.

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.

This is an abridged version of an article by Alison Smith and Dr Timothy Clack. The full, original version can be found here.

This opinion piece reflects the views of the author, and does not necessarily reflect the position of the Oxford Martin School or the University of Oxford. Any errors or omissions are those of the author.