The effects of climate change on crop and food production, which are already evident in several regions of the world, show that negative impacts are more common than positive ones.
According to an Intergovernmental Panel on Climate Change briefing Understanding Climate Science: Climate Change Implications for Agriculture without adaptation, climate change is projected to reduce production do to local temperature increases of 2°C or more (above late-20th-century levels) by 2050. While some areas may benefit from higher yields with this warming trend, after 2050, the risk of more severe yield impacts increases and depends on the level of warming.
The agricultural briefing, which is part of a pack from researchers at Cambridge University says that climate change will be particularly hard on agricultural production in Africa and Asia. Global temperature increases of 4°C or more, combined with increasing food demand, would pose large risks to food security globally and regionally.
Greenhouse gas emissions from agriculture comprised about 10–12% of global GHG emissions in 2010. The sector is the largest contributor of non-CO2 GHGs (including methane), accounting for 56% of non-CO2 emissions in 2005. Opportunities for mitigation include so-called ‘supply’ and ‘demand’ side options.
On the supply side, emissions from land use change, land management and livestock management can be reduced, and terrestrial carbon stocks can be increased by sequestration in soils and biomass. Emissions from energy use across the entire economy can be reduced through the substitution of fossil fuels by biomass providing certain conditions are met.
On the demand side, GHG emissions could be cut by reducing losses and waste of food, and by encouraging changes in diet.
The briefing says that the agricultural industry’s own interests are best served by implementing ambitious approaches to mitigation to ensure that key temperature thresholds are not crossed, while also working to enhance resilience in the face of inevitable temperature rises and associated climate events.
While adaptation to climate impacts is possible, largely by extending techniques already in existence, there is a limit to what can be managed. Adaptive capacity is projected to be exceeded if temperature increases by 3°C or more, especially in regions close to the equator.
In all, there are 13 briefings based on the Fifth Assessment Report from the Intergovernmental Panel on Climate Change, and compiled by the University of Cambridge Institute for Sustainability Leadership (CISL), and Judge Business School, in partnership with the European Climate Foundation and sector-specific organisations.
The series includes innovative and easily understandable info-graphics and key facts, and summarizes the likely impacts of climate change on agriculture, buildings, cities, defense, employment, energy, investment, fisheries, primary industries, tourism, and transport. It also looks at the capacity for these sectors to adapt to climate change and to contribute to emissions reductions.
Among the findings highlighted and explained in the series are:
- The significant impact of climate change on agriculture, including reduced crop yields, and predicted food price rises of 37% (rice), 55% (maize), and 11% (wheat) by 2050
- The potential for more energy efficient buildings to play a big part in reducing emissions
- The particular impact on cities of climate change, and the urgency of acting to protect people in urban areas (predicted to be 64% of the world’s population by 2050)
- The significant potential for the energy sector to reduce emissions, including by switching to lower-carbon fuels, improving energy efficiency, and introducing carbon capture and storage
- The disruptive impacts climate change will have on the stability of the financial system
- The potential for losses to global fisheries of up to $40 billion by 2050
- The way climate change acts as a ‘threat multiplier’, driving involuntary migration and indirectly increasing the risks of violent conflict
- The need for additional energy supply investments of between $190-900bn per year from now until 2050, in order to meet the 2°C target.