Heat stress to threaten over 70% of global agriculture by 2045

Almost three quarters of the world’s current food production will face extreme risks from heat stress by 2045, jeopardizing the health of outdoor workers and threatening the world’s supply of key crops, according to new research from Verisk Maplecroft.

Within a generation, a combination of rising global temperatures and humidity will make outdoor working increasingly difficult and even life-threatening, with significant implications not only for the health of the agricultural labor force, but also for food production in major economies such as China, India, Brazil and the USA.

Agriculture ranks highest for both current and future heat stress risks in Verisk Maplecroft's new Industry Risk Analytics dataset, which measures 51 different risks for 198 countries across 80 industries. The data reveals that heat stress already poses an extreme risk to agriculture in 20 countries. That number rises to 64 under future climate conditions, according to an RCP8.5 worst case high emissions scenario, modelling 2°C of warming above pre-industrial levels by mid-century. This will affect countries that currently account for 71% of global food production, with crops such as rice, cocoa and tomatoes set to be worst affected.

“If emissions remain unchecked and temperatures continue to rise, extreme heat-related disruptions to global food supply chains will become increasingly common,” said Will Nichols, Head of Climate and Resilience. “This will further raise prices, strain economies and push millions towards hunger.”

Extreme heat is a cross-cutting risk. It damages crops and lowers yields while triggering fatigue and nausea among outdoor workers, in turn lowering productivity and overall output.

These impacts are felt most acutely by countries where agriculture is heavily reliant on the productivity of outdoor laborers. India, responsible for 12% of global food production in 2020, is by far the largest agricultural producer rated extreme risk for heat stress in the current climate – only Eritrea, Djibouti, Bangladesh, UAE, South Sudan, and Oman have a higher risk.

And this exposure is already impacting global food security: in May 2022 a heatwave scorched India’s harvests, prompting Delhi to impose a ban on wheat exports. The decision was a blow to the international community, who had looked to India – the world’s second largest wheat producer – to fill the supply gap caused by Russia’s invasion of Ukraine.

Elsewhere, sub-Saharan African countries account for 11 of the 20 locations where agriculture faces extreme heat stress risks in current climate conditions, including Sudan, the world’s largest producer of sesame, and Burkina Faso, a major producer of shea. Major Asian rice producers Pakistan and Vietnam also make the list.

Climate change coming for your olives, grapes

Looking ahead to 2045 shows that the outlook is only set to grow bleaker, with heat stress set to pose an extreme risk to agriculture in over 30% of countries. Nine of the 10 worst affected are in Africa, and the continent is also home to the only three countries that receive the worst possible score of 0.00: Ghana (the world’s second largest producer of cocoa), Togo and Central African Republic.

Cambodia, a key rice exporter, slides to the seventh-highest risk country globally under future climate conditions, down from 36th currently. Neighboring Thailand (ranked 31st in current conditions) and Vietnam (14th) aren’t far behind, at 11th and 16th place respectively. Indeed, rice farmers in central Vietnam have already resorted to working through the night to avoid blistering daytime temperatures.

Brazil, the world’s third largest agricultural producer and a primary source of staple foods including oranges, soybeans and sugarcane, is forecast to slip into the extreme risk category within a generation.

Although developing markets are set to bear the brunt under future climate conditions, rising heat stress is a growing issue for agriculture the world over. When comparing rankings under current and future climate conditions, Europe accounts for seven of the 10 countries set to see the largest increase in risk by mid-century.

Montenegro, where agriculture represents 6.4% of GDP and 7.2% of the workforce, is ranked 52nd and extreme risk in the future climate, down from 127th and medium risk currently – the sharpest deterioration recorded by any country covered in the dataset.

Italy, a major producer of staple foods including olives, grapes and artichokes, is ranked 82nd and high risk under future climate conditions, up from 143rd and medium risk.

The USA, the world’s top agricultural exporter, and China, the world’s largest agricultural producer, will both be extreme risk for heat stress by 2045.

But these countries are vast, and heat stress impacts will vary from state to state and province to province. We can add another layer of granularity to our analysis by using our proprietary subnational datasets to generate industry-weighted risk scores for administrative regions.

Doing so reveals that heat stress could pose an extreme risk to agriculture in 11 southern and south-eastern US states by 2045, up from just one today.

The worst performing state under both current and future heat stress scenarios is Florida, where outdoor workers play a vital role in harvesting key crops including oranges, tomatoes and green beans. Indeed, if Florida were to secede from the Union, it would be the 7th highest risk country in the Americas in terms of agricultural heat stress risks by mid-century – performing worse than the likes of Nicaragua, Guyana and Colombia.

China’s highest risk provinces are similarly clustered in the south-east of the country. Heat stress already poses an extreme risk to agriculture in Hainan, Guangdong, Guangxi and Fujian. An additional six provinces are forecast to slip into the extreme risk category by 2045, encompassing most of China’s major rice growing region.

Outdoor laborers will be the first affected as climate change scorches global agriculture. But rising temperatures will place additional strain on global food supply chains that are already reeling from the dual impacts of the pandemic and Russia’s invasion of Ukraine.

As discussed in previous Verisk Maplecroft research, this could trigger a host of secondary impacts, from civil unrest and political instability to mass migration and human rights abuses, with developing and emerging markets on the frontline. But as shown by Europe’s intense summer heatwave, which sparked wildfires in Spain, France and the UK, governments and businesses everywhere need to factor the immediate and secondary impacts of exceptionally high, and rising, temperatures into their resilience planning.

“Companies and investors need to be aware that in highly agrarian economies disruptions to agricultural production will have huge implications for food security, but will also impact employment, national incomes and credit ratings,” concluded Nichols. “Countries facing falling incomes and dwindling food supplies will struggle to mitigate climate impacts or address issues like poverty that not only upend the operating environment, but could also trigger humanitarian crises, political unrest, or even conflict.”