How will climate change affect what you eat?
Overview
From the distressing images of devastating wildfires in Los Angeles to destroyed cars stacked on top of one another following the Valencia floods in October, it is becoming harder to ignore the effects of climate change and how they will impact both people and food security. Here in the UK, we may think we are immune to such climatic disasters but as our food supply chain is global, we will feel the effects sooner than we would like.
Within decades, water sources could run dry in the Mediterranean, which would affect the supply of fresh fruit and vegetables to the United Kingdom during the winter season – British consumers would have to get used to a lack of ‘out-of-season’ produce such as satsumas at Christmas.
It’s not just southern Europe that will feel the impact of climate change. Water scarcity poses a significant future risk to fruit production in Southeast England, affecting the supply of locally grown soft berries. The strawberries for Wimbledon, for example, come from Hugh Lowe Farms, a family-run farm in Mereworth, Kent, and the tennis championship would no longer be synonymous with British strawberries and cream.
We are by no mean comparing these ‘hardships’ to the genuine and horrific situations being faced by many across the globe. But the reality is the impact of climate change on our day to day lives may be felt in small ways, not just dramatic ones, including our food, from prices to availability.
So, let’s take a closer look at the science behind the effects of climate change on food production.
What is the difference behind weather and climate?
Mark Twain succinctly described the difference between weather and climate as “climate is what we expect, weather is what we get.” Climate is the statistical averages of weather over longer timescales, entailing all the Earth’s systems, including the integrated behaviour of the atmosphere and oceans, ice sheets and biosphere, or in other words, all life on Earth.
Whilst NASA scientists recently reported that 2024 was the warmest year since record-keeping began in 1880, it is important to appreciate that it isn’t just about temperature change but also about shifts in rainfall patterns. Increased moisture levels result from a warming atmosphere, which in turn drives an expected increase in global rainfall and other weather extremes like hurricanes and droughts.
The way atmospheric circulation patterns work means that whilst global rainfall is increasing, there are still big regional trends in contrasting directions. The tropics are becoming wetter, the sub-tropics are becoming drier, and the sub-polar regions are once again experiencing more rainfall or snow. This means that the speed of climate change and the biosphere’s ability to adapt are vitally important to our future well-being.
The challenge of food production in a changing world
From an agricultural perspective, this presents significant challenges and opportunities depending on the type and location of food production. This makes climate action and adaptation desperately important, particularly as precipitation patterns become increasingly erratic.
Water is essential to human civilisation and agricultural production with excessive or insufficient amounts being problematic. Strangely, climate change can give us both. In some geographical regions, like the Mediterranean, the Middle East, South Africa, some parts of Australia and Southwest USA, fresh water supply could run dry within decades. Some of these areas currently provide significant amounts of fresh fruit and vegetables to the United Kingdom during the winter season.
In Southeast Asia, increased flooding and rising sea levels are projected to threaten the population. Longer growing seasons in the Northern latitudes could benefit food production, albeit with an increased risk of extreme weather events that damage crops and disrupt supply.
Water, water everywhere and not a drop to drink
An often-overlooked cause of drought is the loss of moisture into the atmosphere through evaporation, meaning some mid latitude regions are experiencing slightly increased levels of rainfall but still experiencing worse droughts. This is because increased temperatures cause warmer soils and warmer vegetation which lose moisture through evaporation.
In the United Kingdom, water scarcity is increasingly challenging in the Southeast and East of England, where annual rainfall is well below the UK average and agricultural hubs require significant water extraction for crop production alongside increased water consumption from densely populated urban areas. The impacts of climate change pose a significant future risk to fruit production in the Southeast of England, whilst offering some benefits to wine producers.
Extreme weather events will become more common
Climate scientists are unanimous in their observation that something profound is happening to our climate from burning fossil fuels. By warming the planet by just one degree Celsius, we double the number of extreme heatwaves. Climate change has turned events like the deadly 2003 European heatwave, the worst on record for Europe, from once in a thousand years to once in twenty years. Statistical modelling shows that modest temperature rises could make the 2003 heat wave a two-year event, posing a significant risk to food production and life.
The tipping point caused by ice sheet melt
Tipping points, commonly discussed in the climate debate, are crucial because they represent abrupt threshold responses to environmental changes that are exceedingly difficult to reverse, and they may remain irreversible even if CO2 levels are returned to pre-industrial levels. Examples include the positive feedback loops from melting continental ice sheets, which, once accelerated, initiate a domino effect leading to tens of metres of global sea level rise. The melting of ice sheets risks profoundly changing the Atlantic Meridional Overturning Circulation (AMOC), which is an oceanic conveyor belt that transports heat and energy. This system moves warm water from tropical regions, such as the Gulf Stream, northward across the Atlantic to the United Kingdom. Scientists have reported that the AMOC has weakened by 15% as Greenland has lost a trillion tonnes of ice from glacial retreat since 1985.
Ritchie et al, 2020, undertook the most detailed study to date on what might happen to UK agriculture because of AMOC collapse. Models show that abrupt AMOC collapse without technological change would dramatically reduce the overall area of the UK arable production from 32% to 7% of land. This would profoundly change the nature of UK farming.
Climate change increases food prices
Climate change can seriously undermine global food security and destabilise economies. The transitory shocks that led to food spikes in 2007 and 2010 would only be a small fragment of the loss that a tipping point like an AMOC collapse would cause.
The science of climate change impacts shows us that warming the planet to more than two degrees Celsius above pre industrial levels would cause the most harmful and irreversible climate changes. Great urgency and action are needed to tackle climate change, though science tells us that we can still address this problem. The challenge sits with politics, policies and personal action.
Further reading
Ritchie et al, 2020. Shifts in national land use and food production in Great Britain after a climate tipping point. Nature Food, 1(1), pp.76-83.
Website IPCC: AR6 Synthesis Report: Climate change 2023
Website: https://www.scientificamerican.com/article/droughts-and-floods-may-level-off-until-2050-but-then-watch-out/. Michael Mann Professor of Atmospheric Science, Pennsylvania State University.
Myers et al, 2017. Climate change and global food systems: potential impacts on food security and undernutrition. Annual review of public health.