Global Environmental Change

Global Environmental Change - Outline . 1 Introduction . The Earth system is experiencing dramatic environmental change: biogeochemical, ecological, climatic. Some change is natural, but most can be attributed to human activity. The interconnections and feedbacks among natural and human systems greatly complicate our ability to foresee the consequences of our actions. 1.1 Context of changes . * Environmental change not unique to modern time. * Alarm arises from likely impacts and potential to foresee (and avert) harmful change. * Our role as custodians for larger tapestry of biological diversity. * Particular responsibility of industrial nations: those responsible for changes are not those most vulnerable to its impacts 1.2 Purpose of book . * Basic information on major aspects of Earth system changes and their causes. * Road map for those who want to pursue further study. * Highlight connections between fields that are often compartmentalized. * References to current scientific literature, web resources. * Stimulate informed action to minimize harmful impacts 2 The physical climate system 2.1 Radiation 2.1.1 Earth's radiative balance 2.1.1.1 Natural variations in radiative forcing 2.1.1.2 Albedo; forcings vs feedbacks 2.1.2 Greenhouse gases: 2.1.2.1 CO2, CH4, N2O, chlorofluorocarbons, O3 2.1.2.2 Basic information on each: sources/sinks, residence times, recent histories 2.1.3 Tropospheric aerosols 2.1.3.1 Sources and types 2.1.3.2 Radiative effects: direct, semidirect, indirect 2.1.3.3 Atmospheric hydrologic impacts 2.1.3.4 Observations and human/ecological impacts: plumes off Asia and Africa; remote air quality impacts; coral disease vector? 2.1.4 Stratospheric ozone depletion 2.1.4.1 Background: O3 distribution; Mechanisms of production and destruction 2.1.4.2 Observations (Antarctic) - seasonal dependence, extent and amplitude of depletion. 2.1.4.3 Chemistry: O3 destruction by chlorofluorocarbons; Cl reservoir compounds; roles of Br and N2O 2.1.4.4 Relationships with global warming: radiatively active gases; relate to stratospheric temperatures 2.1.4.5 Global depletion of stratospheric O3 2.1.4.6 Montreal protocol (plus amendments) and the projected recovery of Antarctic ozone hole. BOX: comparing the policy responses to ozone depletion and climate change 2.2 The modern climate system 2.2.1 Surface ocean and atmosphere 2.2.1.1 Atmospheric Hadley circulation 2.2.1.2 Surface ocean currents 2.2.1.3 Natural climate patterns/systems: the El Nino/Southern Oscillation (ENSO), monsoons, annular modes, multidecadal modes 2.2.1.4 Thermohaline/deep ocean circulation 2.2.1.5 Climate extremes: tropical storms, drought, flood, heat wave. BOX: Forecasting ENSO and its impacts 2.3 Paleoclimatology: climate lessons from the past 2.3.1 Paleoclimate introduction 2.3.1.1 Motivations 2.3.1.2 Methods 2.3.2 Temperature reconstructions 2.3.2.1 Past 2 millennia: Late 20th century is warmer than any recent period 2.3.3 Drought 2.3.3.1 "Megadroughts" a naturally occurring phenomenon 2.3.4 Modes of variability (ENSO, monsoons) 2.3.4.1 Natural variability large, and sensitive to radiative forcing (Holocene) 2.3.5 Thermohaline circulation 2.3.5.1 Past changes large, abrupt 2.3.5.2 Sensitivity to future change?. Box: Abrupt change - beyond the North Atlantic paradigm; is this the climate system's normal way of behaving? 2.4 Observing and simulating climate change 2.4.1 Climate models 2.4.1.1 Types 2.4.1.2 Limitations 2.4.1.3 Validation 2.4.2 Current and future climate trends - observations and predictions 2.4.2.1 Temperature: means, extremes; stratospheric vs tropospheric 2.4.2.2 Hydrologic: Amount and intensity of precipitation; drought; flood; storms/hurricanes; vapor; clouds 2.4.2.3 Systems: ENSO, monsoon 2.4.2.4 Cryosphere: glaciers, snow cover, sea ice, ice sheets, frozen ground. Box: The Intergovernmental Panel on Climate Change and assessing the state of the science 3 Biogeochemical systems 3.1 Carbon cycle overview 3.1.1 Global system; sources, sinks, reservoirs, fluxes 3.1.1.1 Natural and anthropogenic components - relative scales. BOX: Carbon isotopes as tracers of carbon cycle processes 3.2 Terrestrial carbon cycle 3.2.1 Basic processes and concepts: photosynthesis, respiration, turnover time, soils. vegetation 3.2.2 Ways of measuring ecosystem carbon 3.2.3 Regional results: Amazon; Arctic; temperate forests in N America, Europe 3.2.4 Current and future terrestrial carbon budget. BOX: Managing ecosystems for carbon - examples 3.3 Marine carbon cycle 3.3.1 Inorganic aspects: gas flux; carbonate and alkalinity; ocean acidification 3.3.2 Organic aspects: nutrients; biological pump; dissolved organic C 3.3.3 Future of the ocean carbon sink: biological pump vs circulation. BOX: Iron fertilization 3.4 Global carbon cycle revisited: Anthropogenic perturbation 3.4.1 Summary of anthropogenic sources and sinks 3.4.1.1 Using CO2 measurements, C isotopes, O2 concentrations 3.5 Nitrogen cycle 3.5.1 Processes and terminology 3.5.1.1 Fixation, denitrification, 3.5.1.2 Forms 3.5.2 Global cycle: natural and anthropogenic 3.5.2.1 Marine 3.5.2.2 Terrestrial 3.5.3 Impacts of excess - terrestrial systems 3.5.3.1 Carbon fixation (N fertilization) - estimates 3.5.3.2 Ecosystem acidification 3.5.4 Impacts of excess - marine systems 3.5.4.1 Productivity stimulus; eutrophication; "dead zones". BOX: Yaqui Valley/Gulf of California story 3.6 Biogeochemistry of other greenhouse gases 3.6.1 Methane 3.6.1.1 Key processes 3.6.1.2 Sources and sinks 3.6.1.3 Recent time history: changes in growth rate 3.6.2 Tropospheric ozone 3.6.2.1 Production - needs both volatile organic compounds and nitrogen oxides 3.6.2.2 Sources of VOCs, NOx 3.6.2.3 Impacts 4 Drivers of environmental change 4.1 Energy 4.1.1 Basic numbers: usage, sources, consumption, production 4.1.1.1 Global, regional/country example 4.1.1.2 Break down by end use 4.1.1.3 Projections - regional and by end use 4.1.2 Oil 4.1.2.1 Production - regional breakdown 4.1.2.2 Supply: "peak oil" debate 4.1.2.3 Nonconventional sources; oil shale, tar sands - issues 4.1.3 Coal 4.1.3.1 Production - regional differences 4.1.3.2 Supply - regional differences 4.1.3.3 Making coal more useful: cleaning; C sequestration (refer to other section); gasification? 4.1.4 Supplies - noncarbon alternatives 4.1.4.1 Hydrogen: complications from production method; need for infrastructure 4.1.4.2 Renewables: Sufficient? 4.1.4.3 Nuclear: issues related to waste (Yucca debate), economics/subsidies. BOX: Stabilization wedges (current technologies to stabilize growth of atmospheric GHGs) 4.2 Population and Consumption 4.2.1 The demographic transition: populations stabilize as country develops 4.2.1.1 Examples from high-growth, stable, declining 4.2.2 Population trends and regional aspects 4.2.2.1 Age structures 4.2.2.2 Other aspects: urbanization, coastal, AIDS 4.2.3 Consumption 4.2.3.1 Different consumption levels determine "footprint" of added population 4.3 Land Use 4.3.1 Deforestation and Fire 4.3.1.1 Clearcutting vs other means of forest impoverishment (logging, fragmentation, etc.) 4.3.1.2 Estimates of land cleared or affected, carbon lost 4.3.1.3 Consequences: physical climate/hydrology; biodiversity; biogeochemical) 4.3.1.4 Biomass burning and its atmospheric consequences 4.3.2 Agricultural expansion and intensification (link to previous section) 4.3.2.1 Consequences of tillage: soil lost; C lost 4.3.2.2 Other aspects of agricultural intensification: chemical and mechanical requirements; genetic diversity lost; factory farm pollution; etc. 5 Impacts of environmental change 5.1 Ecological 5.1.1 Observed impacts 5.1.1.1 Range shifts; phenology; behavior; extinctions; fire 5.1.2 Biodiversity 5.1.2.1 Basics on biodiversity (types, value, etc.) 5.1.2.2 Diversity = resiliency (insurance) 5.1.2.3 Hotspots 5.1.3 Case studies 5.1.3.1 Coral reefs 5.1.3.2 Arctic 5.1.3.3 (Others?). BOX: invasive species impacts 5.2 Sea level 5.2.1 Basic processes 5.2.1.1 local vs global 5.2.1.2 eustatic 5.2.1.3 thermal expansion 5.2.2 Observations: what are true rates of rise 5.2.2.1 Satellite 5.2.2.2 Tide gauge 5.2.3 Predictions 5.2.3.1 Modeling future changes 5.2.3.2 Ice sheets and fast ice processes - wildcard. BOX: Integrated impacts of global change on low-lying coastal communities: sea level, storm surges, population growth, ecosystems. 5.3 Disease and health 5.3.1 Relate to natural climate variability 5.3.1.1 ENSO-cholera, hantavirus, Rift Valley fever; many others 5.3.2 Future changes in infectious disease 5.3.2.1 mosquito-borne, coccidiomycosis, water-borne, others 5.3.3 Future changes in unhealthy extremes 5.3.3.1 Heat waves, storms 5.3.3.2 Air quality 5.4 Agriculture 5.4.1 Prediction of productivity 5.4.1.1 Model predictions 5.4.1.2 Geographic and socioeconomic differences 5.4.1.3 Issues in forecasting - examples 5.4.2 Uncertainties 5.4.2.1 Direct effects of CO2 5.4.2.2 Other limits/uncertainties: water, ozone, nutrient concerns, need for capital-intensive measures 5.4.2.3 Adaptations on many scales, from individual farmer practices to genetic research programs 5.5 Water 5.5.1 Quantity 5.5.1.1 Impacts are regional 5.5.1.2 Impact of cryospheric change 5.5.1.3 Impact on infrastructure 5.5.1.4 Demand more of an issue than climate change per se; "soft paths" hold hope for increasing efficiency of use 5.5.2 Quality 5.5.2.1 Consequence of socioeconomic, population changes 5.5.2.2 Waterborne diseases 6 Societal action on environmental change: minimizing the impacts 6.1 Mitigation AND adaptation needed 6.2 Motivation for actions 6.2.1 Recognition of impacts 6.2.2 Ethical dimensions 6.2.3 Uncertainty issue 6.2.4 Risk-assessment: "insurance" 6.2.5 Cost-benefit: limits of economic approach 6.2.6 No-regrets strategies 6.3 Climate change policy 6.3.1 International 6.3.1.1 United Nations Framework Convention on Climate Change 6.3.1.2 Kyoto protocol: basic structure, provisions, mechanisms; interest groups 6.3.1.3 Beyond Kyoto 6.3.2 US role - as major emitter and technology developer 6.3.2.1 Position and actions - national 6.3.2.2 Politicization and public perception: "skeptics", "balance", and other distractions 6.3.2.3 Local/state actions: Cities, states setting emissions targets 6.3.3 Legal actions 6.3.3.1 International, native nations, regional 6.3.4 Industry 6.3.4.1 Increasing acceptance and even support of regulation: Need certainty 6.3.4.2 Public relations vs genuine recognition of problem 6.3.4.3 Emissions targets, other voluntary measures. BOX: Carbon consequences of personal decisions 6.4 Responses 6.4.1 Geoengineering: Carbon sequestration 6.4.1.1 Marine, terrestrial 6.4.2 Geoengineering: Intentional climate modification 6.4.3 Adaptation to climate change 6.4.3.1 Sustainability 6.4.3.2 Resiliency