HONG KONG: Plants and animals are shrinking because of warmer temperatures and lack of water, researchers said on Monday, warning it could have profound implications for food production in years ahead.

“The worst-case scenarios ... are that food crops and animals will shrink enough to have real implications for food security,” Assistant Professor David Bickford, of the National University of Singapore's biological sciences department, said.

Bickford and colleague Jennifer Sheridan trawled through fossil records and dozens of studies which showed that many species of plants and creatures such as spiders, beetles, bees, ants and cicadas have shrunk over time in relation to climate change.

They cited an experiment showing how shoots and fruit are 3 to 17 per cent smaller for every degree Celsius of warming in a variety of plants.

Each degree of warming also reduces by 0.5 to 4 per cent the body size of marine invertebrates and 6 to 22 per cent of fish.

“Survival of small individuals can increase with warmer temperatures, and drought conditions can lead to smaller offspring, leading to smaller average size,” they wrote in their paper which was published in the journal, Nature Climate Change, on Monday.

“Impacts could range from food resources becoming more limited (less food produced on the same amount of land) to wholesale biodiversity loss and eventual catastrophic cascades of ecosystem services,” Bickford wrote.

“We have not seen large-scale effects yet, but as temperatures change even more, these changes in body size might become much more pronounced - even having impacts for food security.”