Changes in Earth’s climate is expected to make vegetables significantly scarcer across the world unless new varieties of crops and new methods of cultivation are adopted.

By the end of this century, less water and hotter air will combine to cut average yields of vegetables – which are crucial to a healthy diet – by nearly one-third, said the report in the Proceedings of the National Academy of Sciences.

Scientists are expecting a 7.2 Fahrenheit (4 Celsius) increase in temperature by 2100 of the rate of global warming moves at the current trajectory. The report says that average yield could reduce by 31.5 per cent.

“Our study shows that environmental changes such as increased temperature and water scarcity may pose a real threat to global agricultural production, with likely further impacts on food security and population health,” said lead author Pauline Scheelbeek of the London School of Hygiene and Tropical Medicine.

Southern Europe, large parts of Africa and South Asia may be particularly affected.

A few previous research pointed that crop production may increase manifold due to rise in carbon dioxide, however, the current study found that any such boost would negate the growth due to rise in greenhouse gases, reduced water availability for irrigation and rising temperatures.

“We have brought together all the available evidence on the impact of environmental change on yields and quality of vegetables and legumes for the first time,” said senior author Alan Dangour, also of LSHTM.

The agricultural sector needs quick and drastic measures to increase its resilience to environmental changes and this must be a priority for governments across the world.

A second study in PNAS found that rising temperatures will increase the volatility of corn, the most widely grown crop on the planet.