How does climate change affect agriculture and food security?

At COP28 in Dubai, leaders from more than 130 countries on Friday called for a rethink of global and national food systems to address climate change. 

How does climate change threaten food security?

As fossil fuel emissions warm the planet, they are causing more extreme weather conditions - from heavy rains and droughts to heat waves - as well as a gradual rise in sea levels. All this can affect crops, destroy farmland and make it difficult for farmers to work.

A warming climate is also moving crop diseases and pests to new locations or making infestations more severe, destroying more crops and reducing yields.

Such challenges, coupled with other pressures on food systems - from growing conflicts to restrictions on crop exports by food-producing countries and market speculation - mean that food is becoming less accessible and more people are going hungry.

The UN World Food Program estimates that 333 million people will face "acute" food insecurity in 78 countries in 2023, a huge increase from about 200 million people before the COVID-19 pandemic .

Crop failures are not a new phenomenon: surpluses in some regions have long offset deficits in others, but scientists fear that the greater impact of climate change could lead to simultaneous crop failures in major global breadbaskets, leading to a rapid rise in global hunger.

What is being done to eliminate these threats?

Around the world, many farmers are adapting to climate extremes in a variety of ways, from digging irrigation ponds to capture flood water and store it in case of drought, to introducing new climate-smart seeds and bringing back hardy traditional crops.

But some challenges, such as more frequent and intense heat waves that could make it difficult for farmers to work outdoors, are more difficult to deal with.

Money to help small farmers, who supply about a third of the world's food, adapt to climate risks is also woefully lacking. They received only about $2 billion in 2021, or 0.3% of total international climate finance from public and private sources, according to Amsterdam-based think tank Climate Focus. 

The Climate Focus study, conducted in 13 countries in Asia, Africa and Latin America, found that nearly 440 million smallholder farming households currently spend about US $368 billion annually on adaptation costs, or about US$838 per year.

Analysts say efforts to strengthen global food security must also go well beyond farms to try to curb speculators in food markets, discourage export restrictions and modernize increasingly strained humanitarian aid systems.

Can we find ways to grow more food to compensate for the losses?

Expanding the area under cultivation or increasing the use of fossil fuel-based fertilizers and developing new varieties of crops have long been accepted ways to grow more food.

But agricultural expansion often comes at the expense of forests and other natural ecosystems that are critical to helping curb climate change. For example, nearly 20% of the vast Amazon rainforest is now lost, largely due to soy farming and livestock farming.

Scientists fear that additional deforestation could turn the forest into dry savanna over time, threatening rainfall for agriculture across South America and sabotaging global goals to protect climate and biodiversity.

Efforts to intensify the production of food grown in a given area have shown some success, but often require large amounts of expensive fossil fuel-based fertilizers. However, in recent years, cleaner farming methods have gained new adherents from the United States to India.

But food analysts say the best way to increase the world's supply is not to grow more, but to reduce the huge amount of food wasted every year.

Although the world produces enough food for everyone, about a third is lost or wasted along the field-to-fork supply chain, which estimates the average person throws away 74 kg (163 lb) of food each year, according to the UN.