20 Global Climate Change

Overview of Chapter 20  Introduction to Climate Change  Causes of Global Climate Change  Effects of Climate Change  Melting Ice and Rising Sea Level  Changes in Precipitation Patterns  Effects on Organisms  Effects on Human Health  Effects on Agriculture  Dealing with Global Climate Change © 2012 John Wiley & Sons, Inc. All rights reserved.

Climate Change Terminology  Greenhouse Gas  Gas that absorbs infrared radiation  Positive Feedback  Change in some condition triggers a response that intensifies the changed condition  Infrared Radiation  Radiation that has a wavelength that is longer than that of visible light, but shorter than that of radio waves  Greenhouse Effect  Increase of heat in a system where energy enters (often as light), is absorbed as heat, and released sometime later © 2012 John Wiley & Sons, Inc. All rights reserved.

Introduction to Climate Change  Evidence for Climate Change  16 warmest years since mid-1800s have occurred since 1990  Phenological spring in N. hemisphere now begins 6 days earlier (date the buds of specific plants open)  Warming is not due to natural causes  Human produced greenhouse gases are most plausible explanation © 2012 John Wiley & Sons, Inc. All rights reserved.

Introduction to Climate Change: Mean Annual Global Temperature 1960–2010 © 2012 John Wiley & Sons, Inc. All rights reserved.

Greenhouse Gases  Greenhouse gas concentrations are increasing © 2012 John Wiley & Sons, Inc. All rights reserved.

Causes of Climate Change  Increased concentration of CO 2 (right)  Burning fossil fuels in cars, industry and homes  Deforestation  Burning of forests © 2012 John Wiley & Sons, Inc. All rights reserved.

Greenhouse Effect © 2012 John Wiley & Sons, Inc. All rights reserved.

Pollutants That Cool the Atmosphere  Atmospheric Aerosols  Both human and natural sources  Tiny particles (or sulfur) that remain in troposphere for weeks or months  Sulfur-laden layer in the atmosphere reduces the amount of sunlight reaching earth  Complicates models of climate change © 2012 John Wiley & Sons, Inc. All rights reserved.

Climate Models  Climate affected by:  winds, clouds, ocean currents, and albedo  Used to explore past climate events  Advanced models can project future warming events  Models are only as good as the data and law used to program them  They have limitations © 2012 John Wiley & Sons, Inc. All rights reserved.

Climate Models © 2012 John Wiley & Sons, Inc. All rights reserved.

Effects of Global Climate Change  Wildfire in California © 2012 John Wiley & Sons, Inc. All rights reserved.

Effects of Global Climate Change- Melting Ice and Rising Sea Levels  IPCC projects sea-level rise of18-59cm by 2100  Sea level rise caused in 2 ways  Thermal Expansion  Melting of land ice  Melting has positive feedback  Increased melting decreases ice, which decreases albedo leading to further warming © 2012 John Wiley & Sons, Inc. All rights reserved.

Melting Ice and Rising Sea Levels © 2012 John Wiley & Sons, Inc. All rights reserved Grinnell Glacier, Glacier National Park Insert Figure 20.6a Insert Figure 20.6b Insert Figure 20.6c Insert Figure 20.6d

Case-In-Point Impacts in Fragile Areas  Eskimo Inuit live traditional life dictated by freezing climate  Climate change is altering their existence  Wildlife displaced  Reduced snow cover and shorter river ice seasons  Thawing of permafrost (right) © 2012 John Wiley & Sons, Inc. All rights reserved.

Effects of Global Climate Change- Changing Precipitation Patterns  Some areas will get more water, some areas will have greater droughts © 2012 John Wiley & Sons, Inc. All rights reserved.

Effects of Global Climate Change- Effects on Organisms  Zooplankton in parts of California Current have decreased by 80% since 1951  Affecting entire food chain  Species have shifted their geographic range  Migrating birds are returning to summer homes earlier  Ecosystems at greatest risk of species loss (short term): coral reefs, mountain ecosystems, coastal wetlands, tundra, and polar spas © 2012 John Wiley & Sons, Inc. All rights reserved.

Effects on Organisms - Coral Reefs  Coral reefs can be bleached (right) due to increase in water temperature  Affects coral symbiotes and makes them more susceptible to diseases © 2012 John Wiley & Sons, Inc. All rights reserved.

Effect on Organisms - Vegetation © 2012 John Wiley & Sons, Inc. All rights reserved.

Effect on Organisms - Vegetation © 2012 John Wiley & Sons, Inc. All rights reserved.

Effects on Human Health  Increased number of heat-related illnesses and deaths © 2012 John Wiley & Sons, Inc. All rights reserved.

Effects on Agriculture  Difficult to anticipate  Productivity will increase in some areas and decrease in others  Rise in sea level will inundate flood plains and river valleys (lush farmland)  Effect on pests is unknown  Warmer temperatures will decrease soil moisture - requiring more irrigation  Location (i.e., elevation and altitude) where certain crops can be grown may have to change © 2012 John Wiley & Sons, Inc. All rights reserved.

International Implications of Climate Change  Developed vs. Developing countries  Differing self- interests  Differing ability to meet the challenges of climate change © 2012 John Wiley & Sons, Inc. All rights reserved.

Dealing with Global Climate Change  Two ways to manage climate change  Mitigation: Limiting greenhouse gas emissions to moderate global climate change  Adaptation: Learning to live with environmental changes and societal consequences brought about by global climate change © 2012 John Wiley & Sons, Inc. All rights reserved.

Relationship Between Mitigation and Adaptation © 2012 John Wiley & Sons, Inc. All rights reserved.

Dealing with Global Climate Change - Mitigation  Locate/invent alternative fuels to fossil fuels  Increase efficiency of cars and trucks  Carbon Capture and Storage  Plant and Maintain trees to naturally sequester carbon © 2012 John Wiley & Sons, Inc. All rights reserved.

Dealing with Global Climate Change - Adaptation  Rising sea levels and coastal populations  Move inland  Construct dikes and levees  Adapt to shifting agricultural zones  NYC sewer line © 2012 John Wiley & Sons, Inc. All rights reserved.

International Efforts to Reduce Greenhouse Gas Emission  Kyoto Protocol  Legally binding  Provides operational rules on reducing greenhouse gases  By 2010, 183 countries had ratified it US has not sign it - it will be difficult to implement without US backing EPA is taking it upon itself to define laws associated with CO 2 reduction in US © 2012 John Wiley & Sons, Inc. All rights reserved.