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

Climate ChangeWhat can we

do…

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