Impacts on Food, Fibre and Forests
Changing climate can benefit as well harm agriculture.
This can be seen in the animation given below.
Recent studies indicate that increased frequency of heat stress, droughts, and floods negatively affect crop yields and livestock beyond the impacts of the gradual changes in the climate, creating the possibility for surprises, with impacts that are larger and occur earlier than predicted.
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At present, 40% of the earthâ€™s land surface is managed as cropland and pasture. Natural forests cover another 30% (3.9 billion hector) of the land surface with just 5% of the natural forest area. In developing countries, nearly 70% of people live in rural areas, where agriculture is the largest supporter of livelihoods (IPCC, 2007). The productivity of agriculture, forestry, and fishery systems is driven by a number of climatic variables (temperature, radiation, precipitation, humidity, and so on). Thus, the latitudinal distribution of crop, pasture, and forest species is a function of the current climatic and atmospheric conditions. In mid- to high-latitude regions, moderate warming will benefit cereal crop and pasture yields. However, slight warming in seasonal dry and tropical regions will decrease the crop yield.
For agriculture, forestry, and fishery systems, vulnerability depends on exposure and sensitivity to climate conditions, as well as on the capacity to cope with these changing conditions.
The impact of climate change on food crops and forests will have a huge effect on the socio-economic paradigm of many countries. Model outputs project that food and forestry trade will increase in response to climate change. The export of food products from temperate zone to tropical countries will rise, while the reverse is quite possible in the forestry sector. Thus, climate change will increase the food import dependence for many developing countries.
Findings from Research
- Food crops: CO2 effects increase with temperature, but decrease once optimal temperatures are exceeded for a range of processes, especially plant water use. The CO2 effect may be relatively greater (compared to that for irrigated crops) for crops under moisture stress (IPCC, 2007). Mid- to high-latitude crops benefit from a small amount of warming (about +2 Â°C), but plant health declines with additional warming (IPCC, 2007).
- Forests: Amongst different kinds of forests, largest impacts of climate change are likely to occur earliest in boreal forests. Climate change could also increase the global timber supply and enhance existing market trends of rising market share in developing countries (IPCC, 2007). Further production increase is likely to shift from low-latitude regions to high-latitude regions in the future.