Climate Change Adaptation Energy What is Projected? Bruce A. McCarl Distinguished Professor of Agricultural Economics Texas A&M University mccarl@tamu.edu http://agecon2.tamu.edu/people/faculty/mccarl-bruce/ Climate Change Adaptation Energy Climate Change Effects Climate Change Mitigation

Degree of climate change - Scenarios Long-term projections require assumptions on human activities or natural effects that could alter the climate over decades and centuries. Scenarios can be formed in many ways, from simple, idealized structures, to comprehensive scenarios with internally consistent assumptions on emissions and socioeconomic drivers (e.g., population & economic development). Idealized Concentration Scenarios As idealized scenario, a 1% yr–1 compound increase of atmospheric CO2 concentration until doubled or quadrupled has been widely used in the past The Socio-Economic Driven SRES Scenarios The SRES (Special Report on Emissions Scenarios) scenarios resulted from specific socio-economic scenarios regarding future demographic and economic development, regionalization, energy production and use, technology, agriculture, forestry and land use The climate change projections discussed in AR4 were based primarily on the SRES A2, A1B and B1 scenarios. Scenarios were developed for AR5 using concentrations .

Non climate scenarios Include at least two scenarios "baseline" or "reference" scenario and "mitigation scenario" Assumptions e.g. economic growth, technology, etc. Figure TS.1: Qualitative directions of SRES scenarios for different indicators Source: CC 2001 mitigation p. 24 at http://www.grida.no/climate/ipcc_tar/wg3/015.htm#24

Degree of climate change - RCPs Representative Concentration Pathway Scenarios Representative Concentration Pathway (RCP) scenarios specify concentrations and corresponding emissions, but are not directly based on socio-economic storylines. Representative Concentration Pathways (RCPs) Scenarios that include time series of emissions and concentrations of the full suite of greenhouse gases and aerosols and chemically active gases, as well as land use/land cover. The word representative signifies that each RCP provides only one of many possible scenarios that would lead to the specific radiative forcing characteristics.

Degree of climate change - RCPs Four RCPs produced from Integrated Assessment Models were used in AR5 RCP2.6 One pathway where radiative forcing peaks at approximately 3 Watts per square meter Wm–2 before 2100 and then declines RCP4.5 An intermediate stabilization pathway in which radiative forcing is stabilized at approximately 4.5 Wm–2 after 2100 RCP6.0 An intermediate stabilization pathway in which radiative forcing is stabilized at approximately 6.0 Wm–2 after 2100 RCP8.5 A high pathway for which radiative forcing reaches greater than 8.5 Wm–2 by 2100 From WGI AR5 Box 1.1

Degree of climate change - RCPs From WGI AR5 Box 1.1

Degree of climate change - RCPs From WGI AR5 Box 1.1

Degree of climate change - What is projected Climate models predict increasing emissions will cause a temp increase Figure 1: Global temperature change and uncertainty. From Robustness and uncertainties in the new CMIP5 climate model projections Reto Knutti & Jan Sedláček, Nature Climate Change 3, 369–373 (2013) doi:10.1038/nclimate1716,

Degree of climate change - What is projected Climate models predict increasing emissions will cause a temp increase AR5 WGI 2013 Faq 12.1

Degree of climate change - What is projected IPCC AR5 WG I Figure 12.11 | Multi-model ensemble average of surface air temperature. Hatching indicates regions where the multi-model mean change is less than one standard deviation of internal variability. Stippling indicates regions where the mean change is greater than two standard deviations.

Degree of climate change - What is projected Hotter

Projections are for a drying region Precipitation Precipitation varies with northern gains, subtropic drying Runoff Soil Moisture The graphics team in the TSU has been working on a revised visualization which is depicted here. This is the graphic that we are hoping all regional chapters will use to summarize how climate change is shifting risks and the potential for risk reduction through adaptation and mitigation This graphic has a few key features Source IPCC 2013, WGI http://www.ipcc.ch/report/ar5/wg1/

Projections are for altered river flow The graphics team in the TSU has been working on a revised visualization which is depicted here. This is the graphic that we are hoping all regional chapters will use to summarize how climate change is shifting risks and the potential for risk reduction through adaptation and mitigation This graphic has a few key features What you see is nonstationarity: the future is not like the past Less water in sub tropical regions Milly P.C.D., Betancourt J., Falkenmark M., Hirsch R.M., Kudzewicz Z.W., Lettenmaier D.P., and Stouffer R.J. Climate Change: Stationarity is Dead: Whither Water Management? Science 2008;319:573-74

Projections are for sea level rise The graphics team in the TSU has been working on a revised visualization which is depicted here. This is the graphic that we are hoping all regional chapters will use to summarize how climate change is shifting risks and the potential for risk reduction through adaptation and mitigation This graphic has a few key features WGI AR5 2013 Figure 13.11 | Projections of (a) global mean sea level (GMSL) rise relative to 1986–2005. The likely range is shown as a shaded band. Only the collapse of the marine-based Antarctic ice sheet could cause GMSL to rise substantially above the likely range during the 21st century. medium confidence that addition would not exceed several tenths of a metre

Degree of climate change - What is projected Very likely that heat waves will be more intense, more frequent and longer lasting Precipitation generally increases but with general decreases in the subtropics Precipitation intensity is projected to increase but there would be longer periods between rainfall events. Tendency for drying of mid-continent during summer, indicating a greater risk of droughts in those regions. Sea level projected to rise 1999 and 2099 by 0.18 to 0.59 m. Likely increase in hurricane peak wind intensities - an increase in the numbers of the most intense. Fewer mid-latitude storms- poleward shift of storm tracks Atlantic Ocean Meridional Overturning Circulation (MOC) – Gulf Stream will slow down

So What?

Climate Change can be disruptive Source : National Assessment

Burning Embers – Reasons for Concern

Climate Change can be disruptive Source : IPCC Source : National Assessment

What is Projected - sea level http://maps.grida.no/go/graphic/potential_impact_of_sea_level_rise_on_bangladesh http://environment.newscientist.com/channel/earth/mg19526141.600- huge-sea-level-rises-are-coming--unless-we-act-now.html

What is Projected - sea level Example 1 Sea Level and hurricanes Adapt Structural protection Abandonment http://yosemite.epa.gov/oar/globalwarming.nsf/content/ResourceCenterPublicationsSLRMapsIndex.html http://www.glo.state.tx.us/coastal/erosion/reimbursement/pdf/Surfside_Beach_historic_shorelines.pdf

Types of Effects - National Assessment Increased warming Assuming continued growth in world greenhouse gas emissions, the primary climate models used in this Assessment project that temperatures in the US will rise 5-9ºF (3-5ºC) on average in the next 100 years. A wider range of outcomes is possible. Differing regional impacts Climate change will vary widely across the US. Temperature increases will vary somewhat from one region to the next. Heavy and extreme precipitation events are likely to become more frequent, yet some regions will get drier. The potential impacts of climate change will also vary widely across the nation. Vulnerable ecosystems Many ecosystems are highly vulnerable to the projected rate and magnitude of climate change. A few, such as alpine meadows in the Rocky Mountains and some barrier islands, are likely to disappear entirely in some areas. Others, such as forests of the Southeast, are likely to experience major species shifts or break up into a mosaic of grasslands, woodlands, and forests. The goods and services lost through the disappearance or fragmentation of certain ecosystems are likely to be costly or impossible to replace. Widespread water concerns Water is an issue in every region, but the nature of the vulnerabilities varies. Drought is an important concern in every region. Floods and water quality are concerns in many regions. Snowpack changes are especially important in the West, Pacific Northwest, and Alaska. Secure food supply At the national level, the agriculture sector is likely to be able to adapt to climate change. Overall, US crop productivity is very likely to increase over the next few decades, but the gains will not be uniform across the nation. Falling prices and competitive pressures are very likely to stress some farmers, while benefiting consumers.

Types of Effects - National Assessment 6. Near-term increase in forest growth Forest productivity is likely to increase over the next several decades in some areas as trees respond to higher carbon dioxide levels. Over the longer term, changes in larger-scale processes such as fire, insects, droughts, and disease will possibly decrease forest productivity. In addition, climate change is likely to cause long-term shifts in forest species, such as sugar maples moving north out of the US. 7. Increased damage in coastal and permafrost areas Climate change and the resulting rise in sea level are likely to exacerbate threats to buildings, roads, powerlines, and other infrastructure in climatically sensitive places. For example, infrastructure damage is related to permafrost melting in Alaska, and to sea-level rise and storm surge in low-lying coastal areas. 8. Adaptation determines health outcomes A range of negative health impacts is possible from climate change, but adaptation is likely to help protect much of the US population. Maintaining our nation's public health and community infrastructure, from water treatment systems to emergency shelters, will be important for minimizing the impacts of water-borne diseases, heat stress, air pollution, extreme weather events, and diseases transmitted by insects, ticks, and rodents. 9. Other stresses magnified by climate change Climate change will very likely magnify the cumulative impacts of other stresses, such as air and water pollution and habitat destruction due to human development patterns. For some systems, such as coral reefs, the combined effects of climate change and other stresses are very likely to exceed a critical threshold, bringing large, possibly irreversible impacts. 10. Uncertainties remain and surprises are expected Significant uncertainties remain in the science underlying regional climate changes and their impacts. Further research would improve understanding and our ability to project societal and ecosystem impacts, and provide the public with additional useful information about options for adaptation. However, it is likely that some aspects and impacts of climate change will be totally unanticipated as complex systems respond to ongoing climate change in unforeseeable ways