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Climate Change Corner
Benefits of Mitigation Policies on Climate Change
A study (Warren et al., submitted) examines the implications of mitigated and unmitigated climate
change for four global climate models. An integrated assessment model, CIAS (Warren et al. 2008),
developed by the Tyndall Centre for Climate Change Research (UK), is used to project the impacts of
climate change associated with various emissions scenarios, and in particular to demonstrate the
dramatic extent to which climate mitigation policy would reduce the projected changes in drought
regime for Europe under various scenarios over the 21st century. The emission scenarios, developed
by the Intergovernmental Panel on Climate Change (IPCC) (Nakicenovich and Swart, 2000), are used
to project future unmitigated climate change and have maximum concentrations of CO2 in the
atmosphere of 970 ppm by 2100. The mitigated climate change scenarios have atmospheric CO 2
concentrations stabilised at approximately 450, 500, and 550 ppm by 2100, as well as a further
extreme scenario which stabilizes CO2 concentrations at 400 ppm.
Modelling results show pronounced increases in drying in Southern Europe, especially around the
Mediterranean and the Black Sea, and also in NW Europe in the second half of the 21st century. More
frequent drought events and increased number of months affected by drought are anticipated in these
regions. However, significant impacts still occur except for the most stringent scenarios with
stabilization at 400 to 450 ppm CO2. It has been proved that mitigation has a great potential to
minimize CO2 increases projected after 2050. Nevertheless, very stringent mitigation scenarios
stabilizing CO2 concentrations at 400 to 450 ppm would be necessary to avoid most of the drought
impacts. This echoes the urgent need for effective mitigation policies / measures such as greater use
of renewable energy, public transport and alternative fuels, as well as heightened public awareness.
References:
(1)
Nakicenovich, N., and Swart R. Special Report on Emissions Scenarios. Cambridge, UK, 2000. Cambridge
University Press.
(2)
Warren, R., S. et al. Development of the Community Integrated Assessment System (CIAS), a multi-institutional
modular integrated assessment approach for modelling climate change, and of SoftIAM, its supporting software.
Environmental Modelling and Software, (2008) 23, 592-610.
(3)
Warren, R., R. Yu, T. Osborn, and S. de la Nava Santos, Future European Drought Regimes under Mitigated and
Unmitigated Climate Change: Application of the Community Integrated Assessment System, Submitted.
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This article is contributed by Ms Rita YU of ERM-Hong Kong, Limited with the co-ordination of the
Environmental Division.