Climate change and Agriculture

posted Oct 13, 2009, 12:54 AM by SUSDEC A   [ updated Oct 26, 2013, 1:34 AM ]

Increase in soil water deficits i.e. dry soils become drier, therefore increased need for irrigation but: Could improve soil workability in wetter regions and diminish poaching and erosion risk

Crops

The effect of increased temperature and CO2 levels on arable crops will be broadly neutral:

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The range of current crops will move northward

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New crop varieties may need to be selected

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Horticultural crops are more susceptible to changing conditions than arable crops

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Field vegetables will be particularly affected by temperature changes

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Phaselous bean, onion and sweetcorn are most likely to benefit commercially from higher temperatures

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Water deficits will directly affect fruit and vegetable production

How will climate change effect cropping in tropical and arid Countries?

Grasslands and livestock

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There is unlikely to be a significant change in suitability of livestock for UK systems

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Pigs and poultry could be exposed to higher incidences of heat stress, thus influencing productivity

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Increase in disease transmission by faster growth rates of pathogens in the environment and more efficient and abundant vectors (such as insects)

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Consequences for food quality and storage

Weeds, pests and diseases:

Weeds evolve rapidly to overcome control measures, short lived weeds and those that spread vegetatively (creeping buttercup, couch etc) evolve at the greatest rate:

Grassland and arable weeds could become more tolerant to control measures

 

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Rate of evolution will increase in hotter, drier conditions and in 'extreme years', could lead to some types of herbicide tolerance becoming more common

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Possible increase in the range of many native pests, and species that at present are not economically important may become so

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Surveillance and eradication processes for other significant pests, such as the Colarado beetle will become increasingly important

Predicted effects of climate change on agriculture over the next 50 years

Climatic element Expected changes by 2050's Confidence in prediction Effects on agriculture
CO2 Increase from 360 ppm to 450 - 600 ppm (2005 levels now at 379 ppm) Very high Good for crops: increased photosynthesis; reduced water use
Sea level rise Rise by 10 -15 cm Increased in south and offset in north by natural subsistence/rebound  Very high Loss of land, coastal erosion, flooding, salinisation of groundwater
Temperature Rise by 1-2oC. Winters warming more than summers. Increased frequency of heat waves High Faster, shorter, earlier growing seasons, range moving north and to higher altitudes, heat stress risk, increased evapotranspiration
Precipitation Seasonal changes by ± 10% Low Impacts on drought risk' soil workability, water logging irrigation supply, transpiration
Storminess Increased wind speeds, especially in north. More intense rainfall events. Very low Lodging, soil erosion, reduced infiltration of rainfall
Variability Increases across most climatic variables. Predictions uncertain Very low Changing risk of damaging events (heat waves, frost, droughts floods) which effect crops and timing of farm operations

Source: Climate change and Agriculture, MAFF (2000)

Current projections, from the 4th Assessment report by the Intergovernmental Panel on Climate Change (IPCC) published in 2007, suggest that global temperatures will rise between 1.8oC and 4.0oC (best estimate) by 2100 depending on emissions of greenhouse gases and that global sea levels are likely to rise from anywhere between 180mm and 590mm.  For further details go to the IPCC website.

Pause for thought......Should farmers take into account predicted climate changes when 'planning for the long term future' of their businesses?

Source: http://www.ecifm.rdg.ac.uk/climate_change.htm