Global production of vegetables and legumes could be significantly reduced as temperatures rise and water availability falls.
A research team led by the London School of Hygiene & Tropical Medicine (LSHTM) conducted a systematic review of all the available evidence in order to
estimate the effects on the yields and nutritional quality of crops as a result of changes in key environmental exposures, including increases in greenhouse gases, reduced water availability for irrigation and rising ambient temperatures.
They found that if no action is taken to reduce the negative impacts of climate change on agriculture, average yields of vegetables and legumes could fall by 35% and 9% respectively. In hot regions, like Southern Europe and large parts of Africa and South Asia, increased air temperatures could reduce average vegetable yields by an estimated 31%.
Previous research has shown that raised levels of carbon dioxide would increase crop yields, but LSHTM’s experts said these potential yield benefits are likely to be cancelled out. In fact, reductions in the yields of vegetables and legumes will “substantially alter their availability globally”.
This could have an impact on affordability and consumption of vegetables and legumes in the mid- to long-term, with significant impacts on population health all around the world, they said. New crop varieties must be developed and agricultural technology improved, the team suggested.
A study by the US Global Change Research Program in 2016 showed that rising levels of carbon dioxide could lead to fewer micronutrients in crops and higher carbohydrate content.