Global warming is cutting rice yields (udbytte) in many parts of Asia, according to research, with more declines to come. Yields have fallen by 10-20 per cent over the last 25 years in some locations, BBC online reports Monday.
A group of mainly US-based scientists studied records from 227 farms in six important rice-producing countries such as Thailand, Vietnam, India and China. This is the latest in a line of studies to suggest that climate change will make it harder to feed the world’s growing population by cutting yields.
The latest data come from working, fully-irrigated farms that grow “green revolution” crops, and span the rice-growing lands of Asia from the Indian state of Tamil Nadu to the outskirts of Shanghai.
Describing the findings, which are published in Proceedings of the National Academy of Sciences (PNAS), lead researcher Jarrod Welch said: – We found that as the daily minimum temperature increases, or as nights get hotter, rice yields drop.
The mechanism involved is not clear but may involve rice plants having to respire more during warm nights, so expending more energy, without being able to photosynthesise.
A study published at the begining of last year concluded that half of the world’s population could face a climate-induced food crisis by 2100, with the most extreme summers of the last century becoming routine towards the end of this century.
