Warming of the climate is now unequivocal. The Intergovernmental Panel on Climate Change (IPCC) has projected temperature increases to 2100 based on climate modelling under a range of scenarios (IPCC, 2013). In all cases the global average temperature increases. This summary briefing highlights some of the key challenges the agriculture sector will face in the coming decades as a result of climate change.
– Global warming of 2-6 degrees is expected by the end of 2100. Climate change presents significant challenges for agriculture.
– Uncertain weather conditions, greater variability in rainfall and extreme weather events pose challenges for managing climate risk.
– Crop yield decreases of 25% or more will be increasingly common in the second half of this century.
– Adaptation strategies must be multi-tiered on local, national and international levels
Since the industrial revolution in the 19th century the Earth’s climate has been undergoing rapid warming primarily as a result of unprecedented greenhouse gas emissions. Recent international policy discussions have focused on limiting the warming to within 2 degrees of pre-industrial levels by the end of 2100 (Meinshausen, 2009; Commission of the European Communities, 2007). This is considered to be an upper limit to avoid the dangerous effects of climate change. The recent IPCC Fifth Assessment Report (AR5) predicts that the climate could warm anything between 1-6 degrees by the end of this century, depending on a range of climate mitigation and emission scenarios (Figure 1).
Figure 1: IPCC future projections of global average surface temperature
Stresses on Agriculture
The world’s current population of 7.3 billion people is expected reach up to 9.7 billion by 2050 and 11.2 billion by 2100. The equation here is simple, more mouths requires more food.
Groundwater is the largest source of usable, fresh water in the world. In many regions domestic, agriculture and industrial water needs can only be met by using water from beneath the ground. Many of the global groundwater aquifers are under significant stresses from overuse and poor replenishment due to extreme weather events. 21 of the world’s 37 largest groundwater sources have already passed their sustainability tipping points (Richey et al, 2015a; Richey et al, 2015b).
Although the link between long term climate and individual weather events remains unclear there is consensus that increase in global temperatures will result in greater variability in seasonal rainfall, drought, and weather extremes. The livelihood of billions of people on and around the Indian subcontinent, for example, rely on the timely arrival of the annual monsoon. In a warmer climate the monsoon may arrive late, too early or even be too strong and result in widespread flooding and land loss.
Loss of crop yield
Computer model projections of crop yields for this century show that climate change is already slowing down yield gains in global wheat productions. Similar losses are expected in all the major food crops including rice and maize. These yield losses are expected to be greatest in the second half of the century, when decreases of 25% will be increasingly common.
Climate risk management is integral to a long-term strategy for adapting the agriculture sector to climate change.
Develop strategies to support adaptation
Climate adaptation is necessarily a location specific, continuous learning process. A potential work-around future climate uncertainties is the so called “no-regrets” adaptation where adaptation strategies are developed that manage the risk over a range of possible climate futures.
Manage the risk at different levels
Local level risk can be addressed by integrating local knowledge with scientific and technical knowledge. Using drought tolerant crops, efficient farming methods and shifting cropping seasons are all proven methods of adaptation and increasing crop yields.
National and international level risk management will rely on producing effective science-based legislation and risk management strategies. Insurance for small-holder farmers and increasing access to the latest technologies and knowledge will be critical for long-term effectiveness. Improve coordination of stakeholders’ activities on research, inventory and monitoring.
Ekbal is a PhD researcher at the University of Leeds UK and an earthquake scientist working to understand how energy is stored and released during these natural events. Ekbal is committed to science communication and believes that, through concerted effort, we can make the world a better place for the millions of people living in poverty and that it is our responsibility to help others in need. You can contact Ekbal on Twitter @ekh_rocksci and can read more of his work on his Blog The Pale Blue Dot.