Scientists warn of crop failure ‘uncertainties’ as Earth heats up

Increasing concentration of greenhouse gas in the atmosphere is putting the planet in ‘uncharted waters’ as weather extremes intensify.

A new study has highlighted the possibility of major harvest failures caused by climate change in multiple global breadbaskets as the United Nations warned of a “dystopian future” without immediate action.

Scientists said on Tuesday their report should be a “wake-up call” about the threat climate change poses to our food systems.

In the new research published in Nature Communications, scientists in the United States and Germany looked at the likelihood that several major food-producing regions could simultaneously suffer low yields.

These events can lead to price spikes, food insecurity, and even civil unrest, said lead author Kai Kornhuber, a researcher at Columbia University and the German Council on Foreign Relations.

By “increasing the concentration of greenhouse gasses, we are entering this uncharted water where we are struggling to really have an accurate idea of what type of extremes we’re going to face”, he said.

“We show that these types of concurring events are really largely underestimated.”

The study looked at observational and climate model data between 1960 and 2014, and then at projections for 2045 to 2099.

Simultaneous crop failures

Researchers first looked at the impact of the jet stream – the air currents that drive weather patterns in many of the world’s most important crop-producing regions.

They found a “strong meandering” of the jet stream, flowing in big wave shapes, has particularly significant impacts on key agricultural regions in North America, Eastern Europe and East Asia, with a reduction in harvests of up to seven percent.

The researchers also found this was linked to simultaneous crop failures in the past.

One example was in 2010, when the fluctuations of the jet stream were tied to both extreme heat in parts of Russia and devastating floods in Pakistan, which both hurt crop yields, Kornhuber said.

The study also looked at how well computer models assess these risks and found while they are good at showing the atmospheric movement of the jet stream, they underestimate the magnitude of the extremes this produces on the ground.

Kornhuber said the study should be “a wake-up call in terms of our uncertainties” of the impacts of climate change on the food sector, with more frequent and intense weather extremes and increasingly complicated combinations of extremes.

“We need to be prepared for these types of complex climate risks in the future and the models at the moment seem to not capture this,” he said.

‘Capacity to change’

On Monday, United Nations human rights chief Volker Turk warned of a “truly terrifying” future of hunger and suffering as climate change-driven extremes hit crops, livestock and crucial ecosystems.

He told a UN debate on the right to food that more than 828 million people faced hunger in 2021 and that climate change could increase this number by 80 million by mid-century.

He criticised world leaders for short-term thinking.

“Our environment is burning. It’s melting. It’s flooding. It’s depleting. It’s drying. It’s dying,” he said, evoking a “dystopian future”.

“Addressing climate change is a human rights issue … There is still time to act, but that time is now,” he noted.

Given current policy trends, the planet will be 2.8 degrees Celsius  (5 degrees Fahrenheit) warmer by the end of the century, according to the UN’s climate science advisory panel.

That temperature rise has been described as “catastrophic” for Earth and its inhabitants.

“We must not deliver this future of hunger and suffering to our children, and their children. And we don’t have to,” Turk said.

“We, the generation with the most powerful technological tools in history, have the capacity to change it.”

However, world leaders are currently performing “the choreography of deciding to act and promising to act – and then get stuck in the short term”, he said.

Turk called for an end to “senseless subsidies” of the fossil fuel industry, and said the Dubai COP28 climate summit in November and December needs to be the “decisive game-changer that we so badly need”.

He urged the world to “shun the greenwashers” as well as those who cast doubt on climate science, driven by their own greed.

Source: News Agencies