Food Water Energy for Urban Sustainable Environments (FUSE)

Climate Change

Climate Change

Peter Burek, IIASA

Climate Change is considered under different Representative Concentration Pathways (RCPs) and global coupled ocean-atmosphere general circulation models (GCMs). For example:

  • RCP4.5 (Clarke et al., 2007) is a stabilization scenario where total radiative forcing is stabilized before 2100 by employment of a range of technologies and strategies for reducing greenhouse gas emissions. Its radiative forcing will be 4.5 W/m2 by 2100.
  • RCP8.5 (Riahi et al. 2007) is characterized by increasing greenhouse gas emissions over time representative for scenarios in the literature leading to high greenhouse gas concentration levels. Its radiative forcing will be 8.5 W/m2 by 2100

Based on the RCP scenarios, the GCMs simulate projections on meteorological variables like temperature, precipitation, wind speed, humidity etc.  (CMIP5, 2011). A selection of bias corrected and downscaled GCMs (Frieler et al. 2017) are then used as input to hydrologic models that simulate future streamflow, runoff, soil moisture conditions etc., under different climate change scenarios.

Jordan

For Jordan, the four GCMs suggest that temperatures will rise between 3°C and 6°C by the end of the century depending on the RCP scenario (see fig 1). Precipitation in 2070-2100 will be only 80% (RCP4.5) or only 60% (RCP8.5) of the average annual precipitation from 1971-2005 (see fig 2). Therefore, droughts will be more frequent, longer, and severe. Rajsekhar and Gorelick (2017) show similar results for Jordan.

Figure 1: Average change in temperature using four GCMs under RCP4.5 (light red) and RCP8.5 (dark red) until 2100 for Amman/Jordan. Blue line indicates historical reanalysis data.

 

India

For India, the four GCMs suggest that temperatures will rise between 2°C and 4°C by the end of the century depending on the RCP scenario (see fig 3). In contrast to Jordan, precipitation in 2070-2100 will increase by 25% (RCP4.5) or 50% (RCP8.5) of the average annual precipitation from 1971-2005  and also the variability will increase (see fig 3). Therefore, the risk of floods will increase.

Figure 3: Average change in temperature using four GCMs under RCP4.5 (light red) and RCP8.5 (dark red) till 2100 for Pune / India. Blue line indicates historical reanalysis data.

 

Figure 4: Change in precipitation using four GCMs under RCP4.5 (upper fig.) and RCP8.5 (lower fig.) till 2100 for Pune / India. Red line indicates historical reanalysis data.
  • Clarke, L., J. Edmonds, H. Jacoby, H. Pitcher, J. Reilly, R. Richels. 2007: Scenarios of Greenhouse Gas Emissions and Atmospheric Concentrations. Sub-report 2.1A of Synthesis and Assessment Product 2.1 by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. Department of Energy, Office of Biological & Environmental Research, Washington, 7 DC., USA, 154 pp.
  • CMIP5, 2011. The WCRP Coupled Model Intercomparison Project - Phase 5 (CMIP5) - CLIVAR Exchanges Special Issue, No. 56, Vol 16, 32pp, 2011.
  • Frieler, K., et al., 2017. Assessing the impacts of 1.5 _C global warming { simulation protocol of the Inter Sectoral Impact Model Intercomparison Project (ISIMIP2b), Geoscientific Model Development, 10, 4321{4345, doi:10.5194/gmd-10-4321-2017.
  • Rajsekhar, D. and S.M. Gorelick, 2017. Increasing drought in Jordan: Climate  change and cascading Syrian land-use impacts on reducing transboundary flow,  Science Advances, vol. 3, no. 8, e1700581, doi: 10.1126/sciadv.1700581.
  • Riahi, K. Gruebler, A. and Nakicenovic N. 2007. Scenarios of long-term socio-economic and environmental development under climate stabilization. Technological Forecasting and Social Change 74, 7, 887-935.

Climate Change

Steven Gorelick, Stanford

We will also use the approach developed for Jordan in which we select only those climate models that reproduce climate conditions during the baseline period 1980-2010. This approach represented drought conditions and showed that Jordan's projected climate will have severe drought in terms of their duration and severity. 

        Prior Approach - Jordan

Climate model simulations of temperature change in Jordan compared to 1980-2010 under RCP4.5 and RCP8.5. 

To evaluate the impact of climate change, we develop downscaled estimates based on a set of GCMs for each region.  This provides estimates of temperature an precipitation on regional scale.  We consider climate change scenarios under different Representative Concentration Pathways (RCPs), such as RCP4.5, in which there is a decline in carbon emisssions and RCP8.5, which considers the effects of extreme emissions. The climate model estimates are then used as input to hydrologic models that simulate future streamflow and soil moisture conditions, under these climate change scenarios.  For example, the climate models for Jordan suggest that temperatures will rise between 2 and 6 degrees C by the end of the century, and suggest that droughts will be more frequent, longer, and severe as indicated by the significant reduction in precipitation compared to the period 1980-2010.  

 

The approach is described in detail by Rajsekhar and Gorelick (2017).  

Reference: Rajsekhar, D. and S.M. Gorelick. 2017. Increasing drought in Jordan: Climate  change and cascading Syrian land-use impacts on reducing transboundary flow,  Science Advances, vol. 3, no. 8, e1700581, doi: 10.1126/sciadv.1700581.