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As least half of the global crop production in low latitude areas could be jeopardised as global warming surpasses the threshold of 1.5 degrees Celsius and climate conditions become unsuitable for food production, a new global analysis published in Nature Food has warned.
At the same time, there is also a threat to crop diversity as it was projected to decline on 52 per cent of global cropland in a scenario of global warming exceeding 2°C and on 56 per cent if warming exceeded 3°C.
Researchers from Aalto University, Finland, University of Göttingen, Germany, and University of Zürich, Switzerland, studied 30 major crops under four scenarios of global warming levels ranging from 1.5-4°C and found a considerable increase in the share of agricultural areas shifting to unprecedented climatic conditions if global warming exceeds 2°C.
Around 10-31 per cent of current production would shift outside the ‘climate niche’ to areas where none of the 30 crops were currently grown. This would increase to 20-48 per cent in a 3°C warming scenario.
The authors defined ‘climatic niche’ for each crop based on the current climate conditions in their current production areas. For this purpose, the research applied the ‘safe climatic space’ (SCS) concept, in which they mapped the current climatic space of the major production areas of each crop using three climate parameters: annual precipitation, bio temperature and aridity.
“This means that when cropland shifts outside of the SCS, globally, there is no reference of, for example, agricultural management practices that would support continuing crop production under these novel climate conditions,” said the study published on March 4.
Global percentage net change in total current cropland area within the crop-specific SCSs
Further, the researchers examined which locations would fall outside these SCSs under future climate conditions.
In the Middle East and North Africa, the current crop production would be at considerable risk on nearly 50 per cent of cropland area already under 1.5°C global warming. In the Middle East and North Africa, these areas with considerable risk to current production would cover 69 per cent of the cropland area under 3°C global warming and in South Asia and in sub-Saharan Africa, 60 per cent.
In contrast, especially in the Northern Hemisphere, there are large areas where the current production would not face considerable risk under any studied warming level. These lower risk areas cover 80 per cent of the croplands in North America and 77 per cent of those in Europe and Central Asia.
In terms of decline in potential crop diversity, the most spatially extensive decline was observed near the Equator, for example, in sub-Saharan Africa and South Asia, where the diversity of food crops would decrease on more than 70 per cent of the current cropland area if global warming exceeds 2°C.
Previous research has also estimated that by 2100, up to 30 per cent of global food crop production could experience climate conditions that currently do not host major crop production anywhere across the globe.
Therefore, the risk of reduction in croplands, especially for major crops like wheat, rice, maize, and soybean was likely to exacerbate the already insufficient food supply and “threaten the livelihoods of agricultural households in several countries”.
The study also pointed that it was unlikely that the adverse effects on crop production in low-latitude regions could be offset by incremental adaptations in agricultural management practices.
“Therefore, in addition to climate change mitigation efforts, it is critical to support the food supply in these regions by strengthening national and international climate governance, for example, by creating trade arrangements and financing for innovative adaptation in low-income countries,” it said.