Lesson 5 – Greenhouse Effect and Global Warming Part 1 PDF

Greenhouse Effect and Global Warming ESENV130- Environmental Science and Engineering Part 1 At the end of the session, the students shall be able to: Explain the relationship between the greenhouse effect to global warming. Demonstrate that greenhouse...

Greenhouse Effect and Global Warming ESENV130- Environmental Science and Engineering Part 1 At the end of the session, the students shall be able to: Explain the relationship between the greenhouse effect to global warming. Demonstrate that greenhouse gases are the most significant factor controlling surface temperature. Discuss the Human Impact on the Ozone Layer and the Effects of Ozone Depletion Show importance about Government Roles in Reducing the Threat of Climate Change. How Might the Earth’s Climate Change in the Future? Considerable scientific evidence indicates that emissions of greenhouse gases into the earth’s atmosphere from human activities will lead to significant climate change during this century. Past Climate Changes Glacial and interglacial periods Global cooling and global warming Measurement of past temperature changes Rocks and fossils Ice cores from glaciers Tree rings Historical measurements since 1861 AVERAGE TEMPERATURE (over past 900,000 years AVERAGE TEMPERATURE (over past 130 years TEMPERATURE CHANGE (over past 22,000 years TEMPERATURE CHANGE (over past 1,000 years Stepped Art Fig. 15-16, p. 383 The Greenhouse Effect Earth’s natural greenhouse effect Natural greenhouse gases Water vapor (H2O) Carbon dioxide (CO2) Methane (CH4) Nitrous Oxide (N2O) Evidence to Support Global Warming (1) Intergovernmental Panel on Climate Change 2007 IPCC report Rise in average global surface temperature 10 warmest years on record since 1970 Evidence to Support Global Warming (2) Annual greenhouse gas emissions up 70% between 1970 and 2008 Changes in glaciers, rainfall patterns, hurricanes Sea level rise in this century 4–8 inches Sept. 1979 Sept. 2008 Russia Russia * * North North pole Greenland pole Greenland Alaska (U.S.) Alaska (U.S.) Canada Canada CO2 Is the Major Culprit 1850: 285 ppm 2009: 388 ppm Over 450 ppm is tipping point 350 ppm as intermediate goal Science Focus: Scientific Consensus about Future Global Temperature Changes? Temperature as a function of greenhouse gases Mathematical models Model data and assumptions Predictions and model reliability Recent warming due to human activities  Sun Troposphere Cooling from increase Aerosols Greenhouse CO2 emissions from Heat and Heat and gases Warming CO2 removal land clearing, CO2 removal CO2 emissions from by plants and fires, and decay decrease soil organisms Ice and snow cover Shallow ocean Land and soil biota Long-term Natural and human emissions storage Deep ocean What Role for Oceans in Climate Change? Absorb CO2 CO2 solubility decreases with increasing temperature Upper ocean getting warmer What Are Some Possible Effects of a Projected Climate Change? The projected change in the earth’s climate during this century could have severe and long-lasting consequences, including increased drought and flooding, rising sea levels, and shifts in locations of agriculture and wildlife habitats. Potential Severe Consequences Rapid projected temperature increase 2 Cº inevitable 4 Cº possible Effects will last for at least 1,000 years Harmful Effects of Global Warming (1) Excessive heat Drought Ice and snow melt Rising sea levels Extreme weather Harmful Effects of Global Warming (2) Threat to biodiversity Food production may decline Change location of agricultural crops Threats to human health  Questions? Clarifications? Thank you for listening!