The Economics of Climate Change C 175 Climate Change Impacts Spring 09 UC Berkeley Traeger 1 Climate Change 112 The Economics of Climate Change C 175 Source http www grida no climate vital 20 htm Spring 09 UC Berkeley Traeger 2 Climate Change 113 The Economics of Climate Change C 175 Crop Yields Source IPCC TAR Spring 09 UC Berkeley Traeger 1 Climate Change 114 The Economics of Climate Change C 175 Risks Associated With Global Warming Source Parry 2001 Spring 09 UC Berkeley Traeger 1 Climate Change 115 The Economics of Climate Change C 175 116 51 Sources IPCC 2008 Spring 09 UC Berkeley Traeger The Economics of Climate Change C 175 Spring 09 UC Berkeley Traeger 1 Climate Change 117 The Economics of Climate Change C 175 Stern Review 2006 Forecast Spring 09 UC Berkeley Traeger 1 Climate Change 118 So what about California Change in number of days with heatwave conditions occurring in Los A Angeles l Sacramento S F Fresno and d El C Centro iin 2070 2099 relative l i to the h 1961 6 1990 average The Economics of Climate Change C 175 And Skiing Spring 09 UC Berkeley Traeger 1 Climate Change 120 The Economics of Climate Change C 175 On fires and uncertainty Spring 09 UC Berkeley Traeger 1 Climate Change 121 On precipitation and uncertainty Emissions Pathways CA Impacts 2004 Con t Fig 6 Fig 6 Winter DJF and summer JJA precip precip change for 2070 2070 2099 2099 relative to 1961 1990 1961 1990 Geographical patterns of precipitation change are consistent across models and scenarios with the greatest decreases occurring on the northwest coast and along the eastern Central Valley and western Sierras The Economics of Climate Change C 175 Spring 09 UC Berkeley Traeger 1 Climate Change 123 Californian biodiversity The number of threatened and endangered species in the state state already the largest in the contiguous 48 states could rise significantly due these combined stresses Extreme events such as floods droughts and wildfires may become more frequent and intense intense Source Excerpts from Preparing for Change Sept 2002 Report by the California Regional Assessment Group for the US Global Change Research Program Program California Climate Risk and Response Fredrich Kahrl and David Roland Holst Dept Ag and NR Econ Research Paper No 08102801 UC Berkeley Nov 2008 The Economics of Climate Change C 175 Five reasons for concern IPCC 2007 Spring 09 UC Berkeley Traeger 1 Climate Change 126 The Economics of Climate Change C 175 Increased Evidence Ri k to Unique Risks U i and d Th Threatened d SSystems There is new and stronger evidence of observed impacts of climate change on unique and vulnerable systems such as polar and high mountain communities and ecosystems ecosystems with increasing levels of adverse impacts as temperatures increase further An increasing risk of species extinction and coral reef damage is projected with higher confidence than in the TAR Third Assessment Report as warming proceeds Spring 09 UC Berkeley Traeger 1 Climate Change 127 The Economics of Climate Change C 175 Increased Evidence Risks of Extreme Weather Events Responses to some recent extreme events reveal higher levels of vulnerability than the TAR TAR There is now higher confidence in the projected increases in droughts heat waves and floods as well as their adverse impacts Spring 09 UC Berkeley Traeger 1 Climate Change 128 The Economics of Climate Change C 175 Increased Evidence Distribution Of Impacts and Vulnerabilities There are sharp differences across regions and those in the weakest economic position are often the most vulnerable to climate change h There h is increasing evidence d off greater vulnerability l b l off specific groups such as the poor and elderly not only in developing but also in developed countries Moreover there is i increased d evidence id th thatt llow latitude l tit d and d lless d developed l d areas generally face greater risk for example in dry areas and megadeltas Spring 09 UC Berkeley Traeger 1 Climate Change 129 The Economics of Climate Change C 175 Increased Evidence Aggregate Impacts Compared to the TAR initial net market based benefits from climate change are projected to peak at a lower magnitude of warming warming while damages would be higher for larger magnitudes of warming The net costs of impacts of increased warming are projected to increase over time Spring 09 UC Berkeley Traeger 1 Climate Change 130 The Economics of Climate Change C 175 Increased Evidence on Ri k off Large Scale Risks L S l Singularities Si l ii There iis hi Th high h confidence fid th thatt global l b l warming i over many centuries t i would lead to a sea level rise contribution from thermal expansion alone that is projected to be much larger than observed over the 20th y with loss off coastal area and associated impacts p There is century better understanding than in the TAR that the risk of additional contributions to sea level rise from both the Greenland and possibly Antarctic ice sheets may be larger than projected by ice sheet models and could occur on century time scales Spring 09 UC Berkeley Traeger 1 Climate Change 131