Heat waves, extreme temperatures and elevated levels of carbon dioxide could significantly reduce crop yields, according to a study by researchers at Norwich-based University of East Anglia. Global warming could threaten the supply of food, especially maize, wheat and soybean across the world if global climate change is not tackled and upturned.
Studies held earlier stated that climate change could decrease the yield of maize globally under a “business as usual” scenario for future emissions of greenhouse gases. The recent study includes heat waves, which could double the losses of the crop.
Extreme temperatures brought about by increase in global mean temperature can be dangerous to crops, particularly around the flowering period of the plant also known as anthesis. During this stage, high temperatures lead to reduced pollen sterility and seed set, thereby reducing the crop yield.
According to Skymet Meteorology Division in India, a heat wave is a prolonged period of weather condition when maximum temperature is more than 40°C and 5°C above the normal average. The impact of heat waves on wheat and soybean are less profound than maize.
Warm climate can make many crops grow quickly but surprisingly reduce yields. The reason is simple; crops tend to grow faster but for some grains faster growth reduces the amount of time that seeds have to grow and mature.
It is true that on doubling carbon dioxide levels, yields of wheat and soybeans could increase by 30 per cent and 10 per cent for corns. However, an increase in temperature, above the crop's optimal level, may counteract the potential increase due to higher carbon dioxide concentrations.
Thus, the study concludes that future heat waves will prove to be detrimental to key global food crops if climate change is not addressed.
picture courtesy- Institute of Physics
