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Food and climate change

The global food system – from fields and farms to our dinner tables and waste bins – provides livelihoods for over 1 billion people.

The 2019 IPCC report on Climate Change and Land states that food supply per capita has increased more than 30% since 1961, with the food system overall producing more than enough calories to feed the world. Latest UN data suggests however that as many as 828 million people were still affected by hunger in 2021, with an estimated 45 million children under the age of five suffering from wasting: the deadliest form of malnutrition.

Our current food system, already under immense and growing pressure from conflicts, economic shocks and deepening inequality, is also threatened by climate change. For example, according to the most recent IPCC conclusions on impacts and adaptation, climate change has already dampened productivity growth and decreased fish stocks. Since we rely on a handful of crops dominated by a few companies, international commodity shortages and price spikes are increasingly likely in a highly interconnected and less resilient system. Further warming, driven by current and future greenhouse gas emissions, is projected to cause declines in crop production and to render major parts of the world unsuitable for existing agricultural models.

The IPCC report projects that the number of people at risk of hunger by 2050 will increase by between 8 and 80 million depending on the level of warming. Those most impacted will be people in Sub-Saharan Africa, South Asia and Central America. Small and mid-sized food producers in these regions play a key role in global food security, as rural households in low- and middle-income countries produce half of the world’s cereals and the majority of fruits and vegetables. However, they already lack the resources to cover their losses from droughts and other climate-related events – which are projected to be worsened by climate change, or to adapt to harsher conditions.

Additionally, if greenhouse gas emissions stay high, up to 30% of current crop and livestock areas will become unsuitable for food production by the end of the century, according to the report. Conversely, if we reduce emissions rapidly, we will lose less than 8% of that agricultural land. In this respect, South Asia, South East Asia, parts of Australia, the Sahel region in Africa and the area around the Amazon basin in South America are the most vulnerable regions.

It is not possible for us to simply adapt to these adverse changes when they happen, or prevent them from happening through present adaptation measures. But cutting emissions along with diversifying food production systems and supply chains will reduce these risks – through increased resilience in global food systems and lower exposure to extreme weather events.

Furthermore, transitioning to greener, more climate-friendly food systems on both supply and demand sides will in itself reduce warming: the UN Food and Agriculture Organization (FAO) estimates that, by 2021, the world’s food systems were responsible for more than one-third of global greenhouse gas emissions from human activity.

What will happen to staple crops?

Dhana Kencana / Climate Visuals

Crop yields have increased over the last six decades, but climate change has already shaved off about 21% of that growth through various impacts like higher temperatures, more frequent and powerful extreme weather events, and changes in pest populations and soil degradation. In this century, the yield growth trend could even reverse by up to 3.3% per decade for crops such as maize, soybean, rice and wheat, depending on location and specific crop variety. And while more carbon dioxide in the atmosphere could potentially boost crops, this will not compensate for this effect’s flip side: increased CO2 levels also reduce the levels of nutrients and vitamins in crops, which makes them less nutritious and can affect pollination and reproduction.

Human-induced warming will exacerbate the risks of simultaneous production failures of key crops in major countries, triggering a domino effect in the food system. Crop yields in different areas of the world are connected via large-scale climate patterns (for example, El Niño and La Niña, or the warming and cooling phases of the periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean). Changes in these patterns driven by climate change may affect crops across the world at the same time.In fact, there is evidence that the risk for simultaneous crop failures has already increased for wheat, soybean and maize compared to 1967-1990. These risks are projected to increase dramatically with further warming, along with the potential for global disruptions in food supply. Climate change also poses the risk of more frequent individual extreme weather events across the world, creating a potential ‘perfect storm’ in food supply chains.

If the global average temperature rises by more than 2°C, then adaptation alone will be insufficient to prevent climate change from reducing crop yields, no matter how much money is invested in adaptation measures. That said, adaptation is indeed necessary, and the costs of it combined with the cost of losses from warming are projected to increase from $63 billion for 1.5°C of warming to $128 billion for 3°C of warming. But there are solutions for cutting this bill. In addition to rapid emissions reductions across sectors, industrial agriculture – which is energy- and water-intensive, fertiliser-heavy and based on monocultures – can be, and will need to be, transformed to take a more diversified and sustainable approach.

How will animal husbandry work?

Robert Benson / Aurora Photos

Large-scale industrial cattle and poultry farming is a significant contributor to human-induced climate change, due to both greenhouse gas emissions from animal farms and extensive land use for feed production. Raising cattle often requires pastures created by clearing woodland, which makes the resulting meat and dairy products especially emission-intensive – the cleared trees no longer capture carbon and instead release previously stored carbon into the atmosphere. Cow digestion also produces methane, a more potent greenhouse gas than CO2, while growing animal feed adds to nitrous oxide emissions from fertiliser use. Taking another perspective, human-induced warming also causes harm to farm animals, as high temperatures affect their health, growth and production.

The IPCC reports offer several ways to address this problem. On the supply side, better management of lands used for grazing, improved handling of animal manure and higher-quality feed can all make livestock rearing and food production less carbon-intensive, reducing its contribution to human-induced climate change. But, ultimately, demand must shift to healthier and more sustainable diets, particularly in developed countries, with more protein coming from plants and seafood rather than from meat.

What about fishing and seafood?

Shibasish Saha / Climate Visuals

Climate change affects the ocean in multiple ways, from the more well-known rising surface temperatures, acidification and sea-level rise to algal blooms and low oxygen levels, parasite spread, marine heat waves and other extreme weather events. Due to the impacts of climate change that we are already experiencing, global yields of fisheries decreased by 4.1% between 1930 and 2010, with some regions seeing losses of 15% to 35%. Marine heat waves in particular, having already caused collapses of local fisheries and aquaculture, are projected to become 20 to 50 times more frequent by the end of the century.

Fish populations are disrupted by profound changes in their habitat. This can interfere with established fishing routes and affect potential seafood catch in tropical regions, adding to already unsustainable practices that include extensive overfishing and the use of plastic nets – these and other discarded, or ‘ghost,’ fishing gear are the deadliest source of ocean pollution. Again, taking another perspective, aquaculture, or ‘farming in water,’ is an increasingly important source of fish, seafood and seaweeds and is also harmed by the impacts of climate impacts.

Useful resources

  • Food and Agriculture Organization of the United Nations (FAO) presents its 2022 State of Food Security and Nutrition in the World in a five-minute video.
  • Environmental impacts of food production from Our World in Data.
  • A 24-minute episode of Radio Davos, a podcast from the World Economic Forum, titled ‘COP26: Feed the world without destroying the climate’.