Crops and grass/Policy issues: Difference between revisions

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{{ComponentPolicyIssueTemplate
{{ComponentPolicyIssueTemplate
|Description=In a baseline scenario, there are significant effects of climate change on crop yields. These differ greatly per region and crop. The assumptions on CO2 fertilisation strongly influence the climate change effect. Without CO2 fertilisation, global average crop yields will decline under a changing climate, while they will increase for most crops when standard assumptions on CO2 fertilisation are used (Figure 6.2.2).  
|Description=Climate change significantly affects crop yields, and these effects differ considerably per region and crop. Assumptions on CO2 fertilisation strongly influence the climate change effect. Without CO2 fertilisation, global average crop yields decline under changing climate but increase for most crops under standard assumptions on CO2 fertilisation (Figure below).  
|Example=Policy interventions that directly affect agricultural production systems typically comprise environmental regulation, such as the use of fertilizers and pesticides. These interventions cannot be directly assessed by the model (e.g. lack of explicit nutrient dynamics, no direct coverage of pest control or water quality). The model, instead, evaluates several indirect policy interventions. Some main examples include the impacts of climate policy, dietary habits, trade patterns and land-use regulation.
|Example=Policy interventions that directly affect agricultural production systems comprise environmental regulation, such as use of fertilisers and pesticides. These interventions cannot be directly assessed by the model because of lack of explicit nutrient dynamics, no direct coverage of pest control and water quality. Instead, the model evaluates several indirect policy interventions, such as impacts of climate policy, dietary habits, trade patterns, and land-use regulation.  
 
Climate policies directly affect atmospheric carbon dioxide concentration levels, the degree of global warming, and shifts in precipitation patterns, all of which impact agricultural productivity and thus indirectly also land-use patterns and water requirements. Climate change impacts on agricultural productivity are subject to several interacting mechanisms. In some regions, climate change and the associated increase in atmospheric CO2 concentrations may lead to increasing yields, such as in regions with temperature limitations (see Figure 6.2.3), while sub-tropical and tropical regions often see a decrease in agricultural productivity. As a consequence, certain areas are abandoned while agriculture expands to other regions (brown and purple regions in Figure 6.2.3). If policy interventions lead to large reductions in greenhouse gas emissions, climate change effects also are reduced, both in terms of direct impact and indirect impacts via land-use dynamics (Figure 6.2.3).  


Climate policies focus on atmospheric CO2 concentration levels, and affect the degree of global warming, and shifts in precipitation patterns. These factors have an impact on agricultural productivity and thus indirectly also influence land-use patterns and water requirements. The impact of climate change on agricultural productivity results from several interacting mechanisms. For instance, climate change and the associated increase in atmospheric CO2 concentrations may increase yields in temperate regions (see Figure below) but decrease agricultural productivity in subtropical and tropical regions. As a consequence, agriculture is abandoned in some areas and expanded to other regions (Figure below). If policy interventions lead to large reductions in greenhouse gas emissions, this directly affects agricultural productivity and associated land-use dynamics (Figure below).


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Revision as of 13:47, 20 May 2014