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Adaptation to Climate Change

Climate change causes a significant shift in the distribution of weather patterns resulting in highly variable environmental conditions that include higher temperatures and shift of seasons; changes in rainfall and subsequent variation in water availability; increased incidence of extreme natural events such as storms, flood and droughts; and a change in atmospheric gas composition. Such fluctuations are having a dramatic impact on the planet; shrinking glacier size, increase in sea levels, shifts in plant and animal ranges and patterns and a reduction in biodiversity. Climate change is therefore one of the major challenges that the world is facing.

Plants are key to mitigating the effects of climate change as they are a major sink of carbon from the atmosphere via photosynthesis. However plants are also a major source of atmospheric carbon via human actions such as burning fossil fuels, deforestation, which accounts for 1.1x1015 grams of carbon per year (Friedlingstein et al 2010 ) and also via their use in agriculture, which is estimated to constitute a approximately 10-12% of all greenhouse gas emissions (IPCC 2007).

Agriculture itself is also directly affected by climate change, for example high temperatures at flowering time reduce pollen viability and grain set in cereals. Global models predicted that a 1°C rise in temperature will decrease yields by up to 10% in a number of crops in all but high latitudes (Lobell et al 2011). Water availability is a major rate-limiting factor for plant growth and since 80% of world agriculture is rain fed, changes in the amount and pattern of precipitation and evaporation will have a significant effect on crop development and yield. In addition, extreme climate events, especially floods, have increased from 14% of all natural disasters in the 1980s to 20 percent in the 1990s and 27% since 2000 (FAO, 2008); this poses a major threat to agricultural harvests. Changing climatic conditions are also altering the patterns of weeds, plant pests and pathogens. For example, phoma stem canker of oilseed rape is likely to spread northwards in Europe and increase its severity as a result of higher winter temperature (Evans et al 2008). Similarly, because of human activity and climate change newly emerging fungal diseases are threatening plant, animal and ecosystems health (Fisher et al 2012).

Plant science can help to build the adaptive capacity to emerging problems by increasing our understanding of the effects of climate change on agriculture, biodiversity and whole ecosystems and using this knowledge to generate more resilient crop varieties such as those with increased drought resistance, water use efficiency and increased disease resistance. This knowledge can also be used to promote the use of alternative and orphan crops, perennial crops, preservation of crop diversity and good agronomic practice. Plant based solutions can also help reduce global emissions of GHG for example by producing crops that make better use of nitrogen to reduce fertilisers use, reducing deforestation via the promotion agro-forestry and tree cropping systems and increasing the efficiency of land use for both food and energy via second generation biofuels and the use of crop waste for biomass.

These approaches, together with precision agriculture, reduced waste, reduced tillage and incentives for environmental friendly farming practices, will help pave the way towards climate smart agriculture.

To begin with the GPC will centre its work in this area on its Stress Resilience initiative.

References

Evans et al. (2008)
Range and severity of plant disease increased by global warming.
J.R. Soc Interface 5 (22) 525

FAO 2008.
The state of food insecurity in the world. High food prices and food security threats and opportunities. Rome.

Fisher et al. (2012)
Emerging fungal threats to animal, plants and ecosystem health
Nature 484, 186

Friedlingstein et al (2010)
Update on CO2 emissions.
Nature Geoscience 3, 811-812

IPCC 2007
Fourth Assessment Report on Climate Change