Carbon Dioxide. Anthropogenic Climate Change. Mauna Loa carbon dioxide measurements show increase over last 50 or so years. What is Carbon Dioxide?

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1 Carbon Dioxide Anthropogenic Climate Change Start of Global Warming Problems Measurements at Mauna Loa Good place to measure average air chemistry Started in 50 s continue to present Mauna Loa carbon dioxide measurements show increase over last 50 or so years What is carbon dioxide? What does it mean? Where does it come from? What is Carbon Dioxide? Colorless gas Not poisonous, but it will not support life Normally a tiny percentage of the atmosphere Produced by: Respiration Burning wood, fossil fuels (anything containing carbon Consumed by: Plants

2 Loss of forests Especially rainforest Less recycling of carbon Some forests are taking up carbon dioxide NE United States Burning of Fossil Fuels Add carbon dioxide to atmosphere Impacts of Increased Carbon dioxide Greenhouse Effect Carbon dioxide is transparent to visible light, but opaque to infra-red radiation Just like window glass Visible light warms earth surface just like inside of greenhouse on a summer day Other Greenhouse Gases Methane Source is livestock, termites 20-times more effective in causing the greenhouse effect than carbon dioxide Chloro-fluoro carbons CFC s Coolants in refrigerators and air conditioners Predictions of Global Climatic Models (GCM s) The problem has been that different models predict different amounts of warming Range from 1.5 to 4.5 o C Hypothesis is that the biggest effects will hit between 2030 and 2050 You will see the results

3 We are engaged in a Giant Biogeochemistry Experiment and We have no Idea How it will Turn Out!!!!! Is there evidence from modern climates that global warming is occurring? The problem is that climate is variable over a long time span Are the effects that we are seeing the result of carbon dioxide? Or, are they just a result of normal climatic variability (This is one of the big questions facing science today)

4 Margaret Davis Tree Migrations So What? Who cares? How does this affect me? Impacts of Warming Tree species will have to migrate to accommodate to climate change Other wildlife species will have to change their ranges There is evidence that this is already happening Change in distribution of moisture on earth Largest changes at poles glacial retreat Shift in climatic zones The big problem is that this will shift where particular crops can be grown A Wisconsin Corn-Belt? Cotton and rice in Illinois? Rise in global sea levels caused by warming of water (already sea level has risen cm) So, What Can We Do? Don t subsidize the use of fossil fuels Encourage use of renewable energy Reduce emissions of methane from landfills and gas handling facilities Place limits on Greenhouse gas emissions sale of permits? Carbon taxes? Nuclear Power???? Reduce deforestation Reduce population growth Some of these suggestions would reduce economic growth That may be a bad thing

5 The Kyoto Treaty Dec Require 38 developed countries to cut greenhouse emission to 5.2% below 1990 levels between 2008 and 2012 Don t require developing coutnries to make any cuts Allow emissions trading The Kyoto treaty wouldn t accomplish much much more reduction needs to be done Not ratified by Congress