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Notes Chapter 19.3 – 19.4 APES
19.3 What Are the Possible Effects of a Warmer Atmosphere?
Rapid atmospheric warming could have serious consequences:
- In short, floods in low-lying coastal cities, forests being consumed in vast wildfires, grasslands
turning into dust bowls, rivers drying up, ecosystems collapsing, extinction of up to half of the
world’s species, longer and more intense heatwaves just to name a few
- Temperatures are rising rapidly globally
- Harmful effects will be unevenly distributed
• Tropics will have more fluctuating temperatures, sea-level rises, and droughts.
- Climate change tipping points will occur – thresholds beyond which natural systems will not
recover
•Atmospheric CO2 concentrations above 450ppm annually = potentially drastic climate
changes that our atmosphere my not recover from
• Global average atmospheric temperatures = continuing on the trend of 2⁰C (3.6⁰C
overall) above global temperature average will change climate drastically.
Tipping points of ice and snow more likely to melt:
- Ice melting due to:
• Warmer air above in both troposphere and atmosphere and warmer water below
in both oceans and lakes
- Positive feedback loop occurs
• Acceleration of melting of arctic ice = more global warming = faster rate more arctic
ice will melt…..pattern keeps repeating IN THE SAME DIRECTION!!!
- Melting of summer arctic sea ice
• Some suggest it could completely melt by 2040
• Changes in arctic seawater temps. can greatly influence the jet stream
- Cause abnormal weather patterns to remain steady for longer periods of time
- Mountain glaciers and ice caps
• Shrinking due to warmer atmosphere
• Can change the hydrologic cycle
- Less water stored as ice released during summer season to drought prone
areas
Permafrost is likely to melt:
- If permafrost in Arctic region melts:
• Increase in more methane gas due to rotting organic remains to completely
decompose
• Demonstrates another positive feedback loop = accelerates projected warming
• Illustration of potential loss of permafrost in the future:
Sea levels are rising:
- By 2100 projected sea levels will rise .5 to 1.5 meters
- Projected irreversible effects:
• Degradation and destruction of 1/3 of coastal estuaries, wetland, and coral reefs due
to displacement and an increase in possible acidity from more CO2 turning into carbonic
acid
• Disruption of coastal fisheries due to displacement and habitat fragmentation
• Loss of biodiversity (see below)
• Flooding and erosion predominately in:
- Low-lying barrier islands and coastal areas
- Agricultural lowlands and deltas
• Contamination of freshwater aquifers
• Submergence of low-lying islands (Caribbean and Philippians)
• Flooding of coastal cities (New York City coastal sections, and coastal sections of
Florida)
• Illustration of what an increase in 3 feet of sea level rise would do to coastal Florida:
Oceans are becoming more acidic:
- Increased acidity of surface waters by 30%
• How it happens?
- CO2 reacting with water can produce carbonic acid (H2CO3)
- Threatens corals, snails, all organisms with shells
- Threatens phytoplankton (base of ocean floor food webs)
Severe droughts more common:
- Positive feedback loop:
• Water vapor warms the atmosphere through evaporation = creates more droughts
(less precipitation falls) = more evaporation from ocean water
- Increased wildfires (less saturated soil and precipitation that falls)
- Declining freshwater surface water = lower water tables for plants to grow
- Dry climate ecosystems will increase
Climate disruption is a threat to biodiversity:
- Amazon rainforest
• Up to 85% could be lost due to atmospheric warming
• Extinctions of many species due to loss of natural habitat
- Southern Ocean
• Phytoplankton declined by up to 90%
• Shrinkage of sea ice = less freshwater = less phytoplankton
- Increase in damaging tree insects and fungi
Food production could decline:
- Regions of farming may shift
• Decrease in tropical and subtropical areas with adequate fertile soil = less plantation
specialized crops
• Increase in northern latitudes, but only for a short time
- Less productivity = soil not as fertile
19.4 What Can We Do to Slow Projected Climate Disruption?
Solving climate disruption is difficult:
- Global problem
• Requires unprecedented and prolonged international cooperation
- Long-lasting political issue
• Voters usually respond better to short-term problems compared to long-term
- Projected harmful and beneficial impacts of climate change are not spread evenly = leads to
more problems for the issues above
- Solutions are controversial (phasing out fossil fuels)
• Could disrupt economy, lifestyles, threaten big companies
Options?
- Mitigation
• Slow disruption by focusing on tipping points
• Adaptation
- Prepare for climate change when it happens
- Try to reduce harmful effects
Top four ways to control/prevent greenhouse gas emissions:
1.) Improve energy efficiency to reduce fossil fuel use
2.) Increased use of low-carbon renewable energy resources
3.) Stop cutting down tropical forests (ancient trees)
4.) Shift to more sustainable agricultural practices
Top six ways to clean up greenhouse gas emissions:
1.) Massive global tree planting (filters out CO2)
2.) Restore wetlands that have been drained for farming
3.) Plant fast-growing perennials on degraded land
4.) Promote biochar
• Biochar = burning of biomass (wood, chicken waste) makes no smoke and orderless
fertilizer Biochar
5.) Preserve and restore natural forests
6.) Capture/store carbon from coal-burning plants
Other solutions:
If all else fails, can resort to geoengineering schemes:
- Injection of sulfate particles into stratosphere
• Could reflect UV light
• Not enough research on all effects to atmosphere (could be too risky)
- Seed oceans with iron
• Promotes growth of more marine algae and phytoplankton = absorbs more CO2
• Once again, not enough research known for all effects
Making CO2 as a regulated pollutant:
- CO2 is classified as a pollutant
• Concentration in the atmosphere must be at a certain level
- 2009 EPA classified several greenhouse gases as regulated pollutants
• Ex’s: CO2, CH4, N2O
Price on carbon emissions through carbon/energy taxes and cap-and-trade policies:
Use of government subsidies:
- Subsidies can be used to:
• Encourage energy-efficient technologies, low-carbon renewable energy sources, more
sustainable food production methods
• Phase out old subsidies to companies that use fossil fuels
- Switch government funding of research and development to clean industries instead of fossil
fuel industries
Governments can cooperate internationally:
- Kyoto Protocol
• 1997 international treaty to slow atmospheric warming and its projected climate
disruption (US not involved)
• Cut emissions of CO2, CH4, and N2O gases to certain levels by 2012 (now 2015)
- Technology transfer
• Developed countries helping less developed by sharing latest green technology
- Protection of large forests
• Especially tropical rain forests that help maintain carbon cycle
Countries and states taking initiatives:
- Costa Rica’s goal to be carbon neutral by 2030
• Generates most electricity by hydroelectric power, wind and geothermal energy
- China, India, and the US must change energy habits (mainly large companies)
Companies are reducing their carbon footprints:
- U.S. Climate Action Partnership
• Consists of companies like IBM, Toyota, GE, and Wal-Mart
• Reducing their own carbon footprints and making profits with using recycled materials
How you can personally reduce your CO2 emissions: