Rising temperatures equals lower food security
For more than 12 months I’ve travelled up, down and across the UK discussing whether the UK, and the west generally, is prepared for coming shocks. When I talk with growers and gardeners, the reactions are interesting. Gardening offers hope, yet already climate change is affecting us. Normal ways don’t always work. Growers at field-level rather than garden scale are more troubled by economic pressures such as labour, costs, input price inflation.
My message is challenging. We face a mix of new and old shocks. What if the highly centralised food retailing system is hit by ransomware (or worse)? What if crazy internet falsehoods create alarm? What if another epidemic hits the huge 4.1 million food workforce? What can the public do to build some resilience, a contribution to bouncing back?
When I started this work in late 2022, such questions seemed weird, almost catastrophising. Events since have made them more real. My ‘Just in Case’ report found that some of our old ways of doing things won’t work so well. (1)
We need to be creative and address fundamentals. What’s the point of gardening or growing? Here the message is surely positive. Why, it’s to feed people, of course! Except, much of gardening and farming isn’t necessarily feeding people.
How can we re-emphasise the importance of growing food? This is now a pressing matter. A recent international study looked at every country on the planet and asked what – if any – of the six major categories of food needed for good health (corn, soybean, rice, wheat, cassava and sorghum) they were growing. (2) Only one country in the world was growing all six: Guyana! This was a theoretical exercise. The UK couldn’t grow many crops. But it’s not growing many it could.
Climate change alters how crops grow and what they yield. A recent Netherlands study compared the crops grown at current and potentially higher future CO2 levels.3 Based on 60,000 measurements across 32 nutrients and 43 crops, it found higher CO2 “lowered levels of plant nutrition”. Calorific content might be retained, yet other nutrients lowered. One answer is to develop new crops and use old varieties. Well done, the Heritage Seed Library!
Biodiversity and food security 🔗
Another answer is to reverse the already catastrophic biodiversity loss. A review by the Government’s National Security Assessment of ecosystems decline warns of major impacts on global and UK food security. (4) Please read it. Crop failures are more likely. The UK will not be able to avoid this, says the report. Interactions between ecosystems – life in water, air, land and sea – are highly likely to cascade.
The UK currently relies on imports for food and fertiliser, and cannot produce enough food “based on current diets”. Here’s where I part company with that report. Assuming existing consumption patterns would be bad for public health anyway. (5) The NHS and all healthcare systems are stretched by poor diet. Population scale dietary change is urgently required. Gardeners eat 70% more fruit and veg than the average Brit. (6)
Recalibrating land use for public health would mean current land use and cropping would change dramatically: fewer commodity crops for ultra-processed foods that contribute to ill-health; fewer crops fed to animals; more diverse crops fed directly to people; more land for woods to sequester carbon – suck out CO2 from the atmosphere.
The good news is that UK consumption of fruit is rising. (7) This is long overdue. The bad news is that 85% of fruit is imported, and the amount we eat is still woefully below health advice. Message to gardeners: plant fruit; eat it.
This expanding science base provides clear messages to us, whether growers or governments. We must take the growing of food direct for consumers more seriously. Spreading gardening skills, as Garden Organic’s new online certificate does, is spot on!
References 🔗
1. Lang T, Neumann N, So A. Just in Case: narrowing the civil food resilience gap. London: National Preparedness Commission 2025.
2. Hultgren A, Carleton T, Delgado M, et al. Impacts of climate change on global agriculture accounting for adaptation. Nature 2025; 642(8068): 644-52.
3. ter Haar SF, van Bodegom PM, Scherer L. CO2 Rise Directly Impairs Crop Nutritional Quality. Global Change Biology 2025: https://doi.org/10.1111/gcb.70568.
4. HM Government. Global biodiversity loss, ecosystem collapse and national security: A national security assessment. London: H M Government, 2026.
5. Stanaway JD, Afshin A, Ashbaugh C, et al. Health effects associated with vegetable consumption: a Burden of Proof study. Nature Medicine 2022; 28(10): 2066-74.
6. Gulyas BZ, Edmondson JL. The contribution of household fruit and vegetable growing to fruit and vegetable self-sufficiency and consumption. Plants People Planet 2023; 3: 162-73. https://nph.onlinelibrary.wiley.com/doi/epdf/10.1002/ppp3.10413
7. Kollewe J. Shoppers buy more fruit than last year in 2026 health drive: The Guardian. 2026 4 February, https://www.theguardian.com/business/2026/feb/03/uk-grocery-price-inflation-january-fruit-yoghurt.