A new United Nations dataset warns that climate change will significantly erode agricultural productivity by the end of the century, posing severe risks to global food security and disproportionately harming countries already struggling to adapt.

The findings, released through the Human Climate Horizons (HCH) data platform by the United Nations Development Programme (UNDP) in collaboration with the Climate Impact Lab, indicate that more than 90% of assessed countries are likely to experience falling yields of staple crops, even after accounting for farmers’ adaptation measures.

According to the analysis, 161 of the 176 countries studied are projected to suffer declining yields of key food crops, including maize, rice, wheat, soy, cassava and sorghum.

Low-income and low-development countries are expected to be hardest hit. “The data show that the world’s poorest countries face some of the steepest losses in agricultural productivity, with median national crop yields projected to decline by around 25-30% by the end of the century under very high emissions,” UNDP said.

Regions in sub-Saharan Africa and parts of Asia are particularly exposed because agriculture depends heavily on rainfall rather than irrigation and because farmers often lack access to finance, technology, or resilient crop varieties. 

But the report also finds major agricultural exporters are not immune. The world’s “breadbasket” economies — large wheat and soy producers — are projected to see declines of up to 40% under severe warming scenarios, raising the prospect of volatility in global food markets.

“Climate change is not just an environmental challenge — it is a profound development crisis,” said Pedro Conceição, director of the UNDP’s Human Development Report Office. “High agricultural yields are important not just for food security, they also sustain livelihoods and open pathways for economic diversification and prosperity. Threats to agricultural yields are threats to human development today and in the future.”

The new projections assess two climate trajectories: one assuming moderate emissions reductions and one assuming emissions remain high throughout the century. The data span more than 19,000 subnational regions across more than 100 countries, covering three time periods — near term (2020–2039), mid-century (2040–2059) and late century (2080–2099). Some of the regions set to be worst affected include parts of China, India and Myanmar. 

The UNDP said the scale and granularity of the dataset offer one of the clearest pictures to date of how a warming climate could reshape global food systems. The findings reinforce calls by developing countries and civil society groups to prioritise food systems in climate negotiations.

The projections also show that reducing emissions significantly limits damage. Under moderate emissions pathways, crop losses by 2100 are less than half of those anticipated under high-emissions scenarios — a trend consistent across both high- and low-income countries.

“The pathway to a sustainable and equitable future lies in human-centred climate action,” Conceição said. “Ensuring that every person retains access to sufficient, nutritious, and reliable food is not only a matter of survival — it is a cornerstone of human dignity and development.”

The Human Climate Horizons initiative provides open-access, evidence-based projections on climate impacts across multiple sectors, including labour productivity, coastal exposure, and mortality risks. The platform aims to support policymakers ahead of increasing climate negotiations pressure and food system instability.