Climate ChangeClimate is what we expect,
weather is what we get.~Mark Twain
Climate Average weather conditions of the Earth or
a particular area
• Main focus: temperature & precipitation
• Minimum period: 3 decades
Climate Change: Historical• Radioisotopes in rocks & fossils
• Plankton & radioisotopes in ocean sediments
• Pollen from the bottom of lakes & ponds
• Tree rings
• Ice cores
• Regular temperature
measurements (1861)
Climate Change
Climate Change: Historical• Volcanic Emissions
• Changes in solar input
• Impacts by meteors
• Changes in air & ocean circulation
Climate Change: Human Activities• Significant increase in greenhouse gases
(CO2, CH4, & N2O) since mid-1700s– Industrial revolution
– Burning fossil fuels
– Deforestation
– Agriculture
Intergovernmental Panel on Climate Change (IPCC)
• Earth’s lower atmosphere is warming
• Most increase in gases are due to human activities
• Combo of human induced changes to air composition & temperature of the atmosphere are beginning to change the Earth’s climate
• Increased greenhouse gas conc. will likely trigger a significant climate disruption this century
• Climate disruption will have ecological, economic, & social effects
IPCC (2010)• 1906–2005: Ave. temp increased about 0.74˚C
• 1970–2009: Annual greenhouse emissions from human activities up 70%
• 2000-2009 warmest decade since 1881
• Past 50 years: Arctic temp rising almost twice as fast as the rest of the earth
• Melting of glaciers and increased floating sea ice
• Last 100 years: sea levels rose 19 cm
Key Players in Climate Change• Carbon Dioxide
• Waste Heat
• Solar Input
• Oceans
• Cloud Cover
CO2 Emissions Role• Mainly burning of fossil fuels
– Burning forest (agriculture)
– Deforestation
• 1850: 285 ppm
• 2010: 389 ppm
• 2050: 560 ppm
• *Feb 2018 408.35ppm
• Tipping point: 450 ppm
Carbon Emitters (2014)Total
1.China (30%)
2.United States (15%)3. European Union(28) (9%)
4. Indonesia (7%)
5.Russia(5%)
Heat Waste• Burning fossil fuels
• Main sources
–Combustion engines
–Power plant
–Lights
Solar Input• No correlation between increased solar
input & increase temperatures
• Since 1975– Troposphere warmer
– Stratosphere cooler
Oceans• Carbon Sink
– Absorbs 25=30% of anthropogenic CO2
– Cooler temps = increased absorption
• Warmer Oceans– Average temp = increase 0.32-0.67⁰C
– Less CO2 absorptions
• Ocean Acidity– Increased 30% in last 200 years
– Affects: coral bleaching, phytoplankton populations, & ability to absorb CO2
Cloud Cover• Increase temp = increased evaporation = increase in clouds
• Low clouds: decrease surface temp
• High clouds: increase surface temp
Climate ChangePossible Effects…
DroughtsSevere/prolonged droughts affect 30% of Earth
• Consequences:– Increased wildfires
– Decrease in water
– Decrease in agriculture
More Ice & Snow Melt• Ice Albedo
More Ice & Snow Melt• Arctic Temperatures
have risen at twice the rate
• Mountain glaciers affected by:
– Average snowfall
– Average temperatures
• Mountain glaciers supply water to rivers
Permafrost Melt• Releases methane
Sea Level Rising• Prediction: 0.8-2 meter rise by 2100
Sea Level Rise Effects• Degradation of coastal estuaries & wetlands
• Disruption of coastal fisheries
• Flooding of low-lying barrier islands
• Coastal flooding
– Shanghai
– New York
– Miami
– Bangkok
– Calcutta
Sea Level Rise Effects• Flooding of agriculture lowlands & deltas
• Saltwater contamination of freshwater
Extreme Weather Increase
• Heat waves
• Hurricanes
– increase 0.8°C = increase in storms by 1/3
– Intensity increase by 45%
• Flooding/droughts increase
Threat to Biodiversity• Most susceptible areas:
–Coral reefs
–Polar seas
–Coastal areas
–Tundra
• Organisms with limited
ranges & temperature
tolerance
Agriculture• Regions of farming
may shift– Decrease at tropics &
subtropics
– Increase in northern latitudes
• Low productivity because of low soil quality
Human Health• Temperature related death increase
• Increase in insects, molds, & microbes
Difficult to do...• Global issue
• Long term political issue
• Impacts are not distributed evenly
• Proposed solutions disrupt economies & lifestyles
Ways to Manage Greenhouse Gases
• Improve energy efficiency
• Increase use of renewable resources
• Stop deforestation
• Shift to more sustainable agriculture
Collect Greenhouse Gases
• Massive tree planting
• Restore wetlands
• Plant perennials on degraded land
• Preserve and restore natural forests
• Stimulate phytoplankton growth
Government Involvement
• Strictly regulate CO2 and CH4
• Carbon tax on fossil fuels
• Cap and trade approach
• Increase subsidies to encourage energy efficiency
Kyoto Protocol• 1997 treaty to slow
climate change
• Reduce CO2, CH4, & N2O emissions by 5.2% by 2012
• Not signed by US
Paris Agreement • 196 parties
• December 2015
• Purpose:
– Adopt “Green” energy sources
– Cut greenhouse emissions
– Limit global temperature rise
– Finding methods to cope with the impact of unavoidable changes in climate
– Developed countries help with financial aid to developing countries in green energy
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