Table 1 Some expected negative impacts of climate change on crop production by regions ^a

Asia

· Crop yields could decrease by up to 30% in Central and South Asia

· More than 28million hectares (ha) in arid and semi-arid regions of South and East Asia will require substantial (at least 10%) increases in irrigation for a 1 °C increase in temperature.

Africa

· One of the most vulnerable continents to climate change and climate variability

· With many semi-arid regions and projected increase of 5% to 8% by the 2080s, likely reduction in the length of growing seasons will render further large regions of marginal agriculture out of production

· Projected reductions in crop yields of up to 50% by 2020

· Fall in crop net revenues by up to 90% by 2100

· Population of 75 to 250 million people at risk of increased water stress by the 2020s and 350 to 600 million people by the 2050s

Australia and New Zealand

· Agricultural production may decline by 2030 over much of southern and eastern Australia, and over parts of eastern New Zealand, due to increased drought and fire

· Change land use in southern Australia, with cropping becoming non-viable at the dry margins

· Production of Australian temperate fruits and nuts will drop on account of reduced winter chill

· Geographical spread of a major horticultural pest, the Queensland fruit fly (Bactrocera tryoni), may spread to other areas including the currently quarantined fruit fly-free zone

· Crop productivity is likely to decrease along the Mediterranean and in south-eastern Europe

· Differences in water availability between regions are anticipated to increase

· Much of European flora is likely to become vulnerable, endangered or committed to extinction by the end of this century

· Increased climate sensitivity is anticipated in the south-eastern USA and in the USA corn belt making yield unpredictable

· Yields and/or quality of crops currently near climate thresholds (for example, wine grapes in California) are likely to decrease

· Yields of cotton, soybeans, and barley are likely to change

· Risk of extinctions of important species

· By the 2050s, 50% of agricultural lands in drier areas may be affected by desertification and salinization

· Generalized reductions in rice yields by the 2020s

· Reductions in land suitable for growing coffee in Brazil, and reductions in coffee production in Mexico

· The incidence of the coffee leaf miner (Perileucoptera coffeella) and the nematode Meloidogyne incognita are likely to increase in Brazil’s coffee production area

· Risk of Fusarium head blight in wheat is very likely to increase in southern Brazil and in Uruguay

· Subsistence and commercial agriculture on small islands will be adversely affected by climate change

· In mid- and high-latitude islands, higher temperatures and the retreat and loss of snow cover could enhance the spread of invasive species including alien microbes, fungi, plants, and animals