Climate Control and Ozone Depletion Chapter 19

CLIMAT WEATHER AND CLIMATE

Core Case Study: Studying a Volcano to Understand Climate Change  June 1991: Mount Pinatubo (Philippines) exploded  Airborne pollutants, deaths, and damage  Affected climate temperature  Climate predictions based on the forecasts of James Hansen of NASA

An Enormous Cloud of Air Pollutants and Ash from Mt. Pinatubo on June 12, 1991

Global Warming and Global Cooling Are Not New (1) What are some natural events that can alter climate? Volcanic emissions Changes in solar input SLOW Movement of the continents Impacts by meteors  Over the past 900,000 years Glacial and interglacial periods

Impact of meteors

Our Climate, Lives, and Economies Depend on the Natural Greenhouse Effect  Without the natural greenhouse effect Cold, uninhabitable earth Four natural greenhouse gases water vapor carbon dioxide methane nitrous oxide Main sources: agriculture, deforestation, and burning of fossil fuels

Human Activities Emit Large Quantities of Greenhouses Gases (1)  Countries with the largest CO 2 emissions according to the book.  1. ___________________and %_____  2. ___________________and %____  3. ___________________ and % ____  4. ____________________ and %

Science: Ice Cores Are Extracted by Drilling Deep Holes in Ancient Glaciers

Human Activities Emit Large Quantities of Greenhouses Gases (2)  Ice core analysis of air pollutants Pages

PRO GLOBAL WARMING 1906–2005: Ave. temp increased about 0.74˚C 1970–2005: Annual greenhouse emissions up 70% Past 50 years: Arctic temp rising almost twice as fast as the rest of the earth Melting of glaciers and floating sea ice Prolonged droughts: increasing Last 100 years: sea levels rose 10–20 cm Hey!!!! C’mon Man  Can’t “cherry pick” datasets. Texas sharp shooter fallacy.  The increase in carbon dioxide and rate of warming is NOT a linear relationship  There was a major volcanic eruption at the proposed beginning of the current warming period. Mt Pinatubo 1991

 The Texas sharpshooter fallacy is an informal fallacy which is committed when differences in data are ignored, but similarities are stressed. From this reasoning a false conclusion is inferred.informal fallacy

The Atmosphere Is Warming Mostly Because of Human Activities (1)  Intergovernmental Panel on Climate Change (IPCC) 90–99% likely that lower atmosphere is warming

Atmospheric Levels of CO 2 and CH 4, Global Temperatures, and Sea Levels

Melting of Alaska’s Muir Glacier between 1948 and 2004

The Big Melt: Some of the Floating Sea Ice in the Arctic Sea

Fig. 19-A, p. 502 Sun Troposphere Cooling from increase Aerosols Greenhouse gases Warming from decrease CO 2 removal by plants and soil organisms CO 2 emissions from land clearing, fires, and decay Heat and CO 2 removal Heat and CO 2 emissions Ice and snow cover Shallow ocean Land and soil biota Long-term storage Natural and human emissions Deep ocean

Enhanced Global Warming Could Have Severe Consequences  Tipping point and irreversible climate change  Worst-case scenarios Ecosystems collapsing Low-lying cities flooded Wildfires in forests Prolonged droughts: grasslands become dust bowls More destructive storms Glaciers shrinking; rivers drying up

Areas of Florida, U.S., to Flood If Average Sea Level Rises by One Meter

Science Focus: Melting Ice in Greenland Illustrated on next slide.  Largest island: 80% composed of glaciers  10% of the world’s fresh water  1996–2007: net loss of ice doubled  Effect on sea level if melting continues

Fig. 19-C (2), p

Low-Lying Island Nation: Maldives in the Indian Ocean would be effected by rising ocean levels

Some Output Methods for Removing CO 2 from the Atmosphere and Storing It. AKA CARBON SEQUESTRATION

Governments Can Enter into International Climate Negotiations: The Kyoto Protocol  1997: Treaty to slow climate change  The Kyoto Protocol Reduce emissions of CO 2, CH 4, and N 2 O by 2012 to levels of 1990 Trading greenhouse gas emissions among countries Not signed by the U.S.

What Can You Do? Reducing CO 2 Emissions

Our Use of Certain Chemicals Threatens the Ozone Layer  Ozone Thinning Seasonal depletion in the stratosphere Antarctica and Arctic  1930: Midgely Discovered the first CFC  1984: Rowland and Molina CFCs were depleting O 3  Other ozone-depleting chemicals

Science Focus: Skin Cancer  Squamous cell carcinoma  Basal cell carcinoma  Melanoma  Effect of UV-B radiation  How safe are tanning salons?

Overall equation for the breakdown of ozone by CFC’s  CFCl 3 + UV Light ==> CFCl 2 + Cl Cl + O 3 ==> ClO + O 2 ClO + O ==> Cl + O 2  This occurs in the stratsophere

Fig. 19-E (2), p. 526 Squamous Cell Carcinoma Basal Cell Carcinoma Melanoma Arising from cells in the upper layer of the epidermis, this cancer is also caused by exposure to sunlight or tanning lamps. It is usually curable if treated early. It grows faster than basal cell carcinoma and can spread to other parts of the body (metastasize). The most common skin malignancy usually is caused by excessive exposure to sunlight or tanning lamps. It develops slowly, rarely metastasizes and is nearly 100% curable if diagnosed early and treated properly. This deadliest of skin cancers involves melanocyte cells, which produce pigment. It can develop from a mole or on blemished skin, grows quickly, and can spread to other parts of the body (metastasize).