statistics time series suggests that between 32-39 per cent of the fluctuations in observed global crop yield is a direct result of climate variability, particularly for maize, rice, wheat, and soybean.9
Extreme climatic conditions reduce yields and increase postharvest losses. They also trigger biophysical reactions in plants in response to environmental stresses. These reactions include concentrating chemical compounds that are harmful to animal and human health. Despite a plant’s various protective responses, in prolonged unfavourable conditions stress can overwhelm its ability to thrive, and can weaken the plant further, leading to increased disease susceptibility. In such cases, either the plant itself or invading microbes can produce specific chemical compounds at levels toxic to human health.
SPEI Global drought map
Video: A dry season
© VOA Learning English
Video Link:
https://www.youtube.com/watch?v=IbpuviS-s4c Photo Credit: Earl D. Walker/
Shutterstock.com
Global drought map – comparison between 1955 to March 2016 Source: Santiago
et.al., 2006 (
http://sac.csic.es/spei/map/maps.html)
© SPEI Global Drought Monitoring
http://sac.csic.es/spei/map/maps.html
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UNEP FRONTIERS 2016 REPORT
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