Adaptation to Climate Change
Not only is agriculture one of the main drivers of climate change, it is also its most significant victim.
Agriculture will be directly affected by all indications and consequences of climate change, such as droughts and floods, storms and tornados, rising sea levels, salinisation of groundwater, more frequent and extreme weather events, increasing species extinction and the spread of old and new diseases. The latest report of the Intergovernmental Panel on Climate Change (IPCC) from 2014 is even more explicit than an earlier assessment from 2007 on which the IAASTD drew upon: Some coastal regions and arid areas will be completely lost for agricultural use. Many regions will suffer heavy losses whereas only a few regions may benefit. Millions of people will lose their homes and their means of existence.
Changes in agricultural productivity
From what we know today, Africa, Latin America and South Asia will suffer the most from the impact of climate change. In some northern regions of Europe, Asia and America, by contrast, agricultural productivity may even increase, at least temporarily, as a result of climate change."Industrialized world agriculture, generally situated at high latitudes and possessing economies of scale, good access to information, technology and insurance programs, as well as favorable terms of global trade, is positioned relatively well to adapt to climate change. By contrast small-scale rain-fed production systems in semiarid and subhumid zones, which continuously face significant seasonal and inter-annual climate variability, are characterized by poor adaptive capacity due to the marginal nature of the production environment and the constraining effects of poverty and land degradation. Sub-Saharan Africa and Central and West Asia and North Africa are especially vulnerable regions." (Synthesis, p. 51)In the medium term, however, today’s major export nations and bread baskets of the world, such as the Midwestern United States, Australia, Brazil, Thailand and Vietnam, as well as large parts of India and China, will be threatened by substantial crop losses. Areas which depend on glacier melt water from the Andes and the Himalayas will be particularly hard hit: As the glaciers melt, they are threatened by floods. Once the glaciers have gone, severe water scarcity will become a problem.
For the first time, the IPCC warns against crop losses by the end of this century which might not be offset even with adaptation, especially if average temperatures rise more than 2 degrees above pre-industrial levels. Many - especially local - impacts of climate change are not yet foreseeable. Global average values mask extremes which could result in entire regions of the world becoming uninhabitable and cause extreme weather events. In areas in which it is impossible to calculate the onset of the rainy season, choosing a date for sowing seeds becomes something of a lottery.
Facts & Figures
In order to keep a good chance of maintaining global warming below 2°C over the 21st century relative to pre-industrial levels, global anthropogenic greenhouse gas emissions must be reduced by 40 to 70% between 2010 and 2050, and fall to zero or below in 2100.
Agriculture, forestry and other land use plays a central role for food security and sustainable development. The most cost-effective mitigation options in forestry are afforestation, sustainable forest management and reducing deforestation, with large differences in their relative importance across regions. In agriculture, the most cost-effective mitigation options are cropland management, grazing land management and the restoration of organic soils.
Climate change could push more than 100 million people into extreme poverty by 2030 primarily due to agricultural shocks and increased incidence of disease. Studies suggest that climate change could result in global crop yield losses as large as 5% in 2030 and 30% in 2080, even with adaptation such as changed agricultural practices and crops.
Heat extremes and changing precipitation patterns will have adverse effects on agricultural productivity, hydrological regimes and biodiversity. In Brazil, without additional adaptation, crop yields could decrease by up to 70% for soybean and up to 50% for wheat at 2°C warming by 2050.
Agriculture contributes approximately 50% to Africa’s total export value and 21% of its total GDP, but as an economic sector it is the most vulnerable and most exposed to climate extremes. It is projected that climate impacts on Namibia’s natural resources would cause annual losses of between one and six percent of GDP, of which livestock production, traditional agriculture and fishing will be hardest hit. This would equate to a combined loss of US$ 461 to 2,045 million per year by 2050.
A one-metre rise in the sea level could submerge 15% of the area of Bangladesh, destroy rice fields in the region and threaten aquaculture in the Mekong delta. In Egypt, nearly 20% of the farmlands are less than two metres above the sea level and will therefore be severely affected by rising sea levels.
It is essential that strategies to adapt to climate change consider traditional knowledge and crops. Traditional crop varieties are cheaper, easier to access, more diverse and more resilient to climate pressures than modern hybrids. Over half of the households surveyed in China still used local varieties of maize and rice which are better adapted to droughts. Evidence from Guangxi province shows that while most modern hybrids were lost in the drought in 2010, most farmer-improved landraces survived.
As water is the most crucial element for growing food, farming will need to adapt to changing rainfall patterns brought about as a consequence of climate change. In sub-Saharan Africa, for example, where climate variability already limits agricultural production, 95% of food comes from rainfed farms. In some East African countries, including Ethiopia, Kenya, Burundi and Tanzania, rainfall dropped by around 15% between 1979 and 2005, causing drastic losses in food production.