20 Global Climate Change

Climate Change Terminology Greenhouse Gas Gas that absorbs infrared radiation Positive Feedback Loop 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

Climate Change (not global warming) Refers to the recent and ongoing rise in global average temperature near Earth's surface caused (mostly) by increasing concentrations of greenhouse gases in the atm. significant change in climate lasting for an extended period of time includes major changes in: Temperature Precipitation Wind patterns Occurring over several decades or longer

Greenhouse gases Greenhouse gases act like a blanket around Earth, trapping energy in the atmosphere and causing it to warm

Increased concentration of CO2 Burning fossil fuels in cars, industry and homes Deforestation Burning of forests Industrialization This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO2 has increased since the Industrial Revolution. (Source: NOAA)

CO2 accounts for 60% of increased heat retention Greenhouse Effect What we know CO2 accounts for 60% of increased heat retention Radiative Forces Capacity of gas to affect energy entering and leaving the atm

Introduction to Climate Change Certain facts about climate are not in dispute What we Know CO2 has the ability to trap heat Methane, Nitrous oxides, CFC’s tropospheric ozone can also trap heat demonstrated in the mid-19th century CO2 ability to capture infrared energy scientific basis of many instruments flown by NASA Based on the knowledge above the following can be assumed Increased levels of greenhouse gases must cause the Earth to warm in response

What we know Sea level rise Global temperature rise Last 100 years rose ~6.7 inches Last 10 years, rose ~12 inches Global temperature rise All major global surface temp reconstructions show that Earth has warmed since 1880. Most of this warming has occurred since the 1970s the 20 warmest years having occurred since 1981 and with all 10 of the warmest years occurring in the past 12 years

What we know Sciences evidence Warming oceans Oceans have absorbed much of this increased heat, with the top 2,300 feet of ocean showing warming of 0.3020F since 1969 Shrinking ice sheets Greenland & Antarctic ice sheets have decreased Data from NASA's show Greenland lost 36-60 cubic miles of ice/year from 2002 - 2006 Antarctica lost 36 cubic miles of ice/year 2002-2005. Declining Arctic sea ice / Glacial retreat / Extreme events / Ocean acidification

Pollutants That Cool the Atmosphere Atmospheric Aerosols - “ Aerosol Effect” Both human and natural sources Sulfur can remain in troposphere for weeks or months Sulfur-laden haze in the atm reflects infrared radiation Complicates models of climate change Negative feedback loop occurs when the result of a process influences the operation of the process itself in such a way as to reduce changes One of the many complications that affects modeling climate change

Climate Models Climate affected by: winds, clouds & ocean currents Advanced models can project future warming events Do there best to factor in all known data Models are only as good as the data Models have limitations

Effects of Global Climate Change - Melting Ice & Rising Sea Levels IPCC – International Panel on Climate Change Projects sea-level rise of 18-59 cm by 2100 Projects temp to rise1.8 to 4.0ºC by 210 Sea level rise - 2 ways Thermal Expansion matter changes in volume in response to a change in temp Melting of land ice Melting has positive feedback Increased melting decreases ice, which decreases albedo leading to further warming (Albedo – Reflections from the a white surface)

Melting Ice & Rising Sea Levels Thermal expansion When water heats up, it expands Melting of glaciers and polar ice caps Large ice formations, like glaciers and the polar ice caps, naturally melt back a bit each summer. Melting of surface ice massive ice sheets that cover Greenland and Antarctica to melt at an accelerated pace Consequences Seawater reaches farther inland destructive erosion, flooding of wetlands, contamination of aquifers & agricultural soils lost habitat for fish, birds, and plants

Case-In-Point Impacts in Fragile Areas Eskimo Inuit live traditional life Alaska & Canada Dictated by freezing climate Climate change is altering their existence Wildlife displaced Reduced snow cover & shorter ice seasons Thawing of permafrost soil at or below the freezing World-wide, permafrost contains huge amounts of dissolved carbon The amount of carbon sequestered in permafrost is 4x the carbon that has been released to the atmosphere due to human activities in modern time

Effects of Global Climate Change- Changing Precipitation Patterns Some areas will get more water, some areas will have greater droughts

Effects on Organisms - Coral Reefs Coral reefs can be bleached due to increase in water temperature & increase in pH (Acidic) Affects coral symbiotes & makes them more susceptible to diseases

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 coral reefs, mountain ecosystems, coastal wetlands, tundra, and polar spas

Effect on Organisms - Vegetation

Effects on Agriculture Difficult to anticipate Productivity may increase in some areas & decrease in others Rise in sea level will inundate flood plains & river valleys Effect on pests is unknown Warmer temperatures will decrease soil moisture - requiring more irrigation Location where certain crops can be grown may have to change

Effects of Global Climate Change Extreme weather More Wildfire in California More extreme hurricanes

International Implications of Climate Change Developed vs. Developing countries Differing self-interests Differing ability to meet the challenges of climate change

Dealing with Global Climate Change Two ways to manage climate change Mitigation: Limiting greenhouse gas emissions 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 Adaptation: Learning to live with environmental changes & societal consequences brought about by global climate change Move inland (Rising sea levels) Construct dikes and levees Adapt to shifting agricultural zones

Relationship Between Mitigation & Adaptation

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. The reason being….. It did not require developing countries to make emission reductions It would seriously harm the economy of the United States Clinton signed it but the senate and house did not It will be difficult to implement without US backing EPA is taking it upon itself to define laws associated with CO2 reduction in US

Those that agree the climate is changing due to human influence 97% of Scientists NASA EPA (Environment protection agency) – of course NIH (National Institute of Health)

Skeptics Modeling system are flawed They do not take into account many factors Can not predict the future Do not have enough good recorded temp data This could be just part of a large weather cycle that has not recorded (We have not been around long enough to record temp over thousands of years) Aren't temperature changes natural? Can't we wait and fix the climate if things get really bad http://www.skepticalscience.com/argument.php http://grist.org/series/skeptics/

Interesting things on-line You tube: Climate change way over simplified (but very interesting to think about) http://www.upworthy.com/one-guy-with-a-marker-just-made- the-global-warming-debate-completely-obsolete-7 As always know your source – all info is bias in one direction or the other. Do your best to get raw (not manipulated) data.