Climate Change● the scientific consensus about future climate change varies. is it junk science? who is right?● Feedback Loops○ exist to promote stability, common in nature○ ex: Brain & body temp○ ex: Isle Royale moose & wolves○ ex: Human deforestation● Cloud formation makes negative feedback (good)● more greenhouse would make positive feedback (bad)● 1991 Phillippines volcano explosion○ NASA scientists predicted it would cool average temp of earth by 0.5C and returnto original by 1995○ was result of increased reflectance from clouds released by volcano: Mt Pinatubo● Temp will rise 0.2C per decade○ melting ice & glaciers > sea level will rise○ lead to sea water entering aquifers, beach erosion■ Flood low-lying urban areas, coastal estuaries, wetlands, coral reefs, barrier islands and reefs○ fun: Maldives Cabinet meeting hold underwater in scuba, 2009● Effects on Biodiversity: Winners & Losers○ Possible effects = geographic range of beach trees○ warming climate > drought, fire, hurricanes○ ex: the beech tree can’t compete with trees better adapted for lower climates■ no resistance to pests.■ not good. decline of forest rapidly● Mitigation/Adaptation○ Carbon sequestration = catching carbon & locking it away■ Deep Sea sequestration proposal by Dan Schrag (Harvard)● ex: Dry ice● CO2 will chemically bond w/ sediments in deep pressure● trap CO2 at source of emission, push it down to deep○ Genetic Engineering/Geo Engineering■ ex: plant more trees■ ex: create albedo by making more clouds○ Adaptations - much more controversial than mitigation○ Conservation○ Remedation/cleanup■ Mitigation = always better but not necessarily as effective, so must consider adaptation.● International Climate Negotiations○ The Kyoto Protocol■ US did not sign/agree, b/c other economic competitors like India & China were exempt.■ Don Shrag used amount of coal & importance to give reason to carbon sequestration■ Goal: decrease emissions■ Reality: some discharges can meet target sooner● cap & trade: create a market for emissions● Cap & Trade○ = a regulatory system that sets limit on overall emissions of pollutants○ allows utilities, manufacturers, & other emitters to “trade” pollution permits, among themselves - like a tax○ worked well 1990 w/ George A Bush - since costs of permits/coal burning = high, factories had to find ways to reduce pollution○ recent President Obama making changesHW: Read Collapse 4-7. Simutexts Climate Change 1-3Averaged over all land and ocean surfaces, temperatures warmed roughly 1.53 degrees Fahrenheit (0.85 degrees Celsius) from 1880 to 2012, according to the Intergovernmental Panel on Climate Change (see page 3 of the 2013 summary report). Because oceans tend to warm and cool more slowly than land areas, continents have warmed the most. In the Northern Hemisphere, where most of Earth's land mass is located, the three decades from 1983 to 2012 were likely the warmest 30-year period ofthe last 1,400 years, according to the IPCC.Human activity since Industrial Revolution of 1750 have produced 40% increase in atmospheric concentration of carbon dioxide, from 280 ppm (1750) to 400 ppm (2015). Emissions come from combustion of carbon-based fuels such as coal, oil, natural gas, along w/ deforestation and soil