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

http://www.youtube.com/watch?v=5qJPTjMnwNk

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 CO2 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 529-30

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.

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 CO2 and CH4, 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

CO2 removal by plants and soil organisms

CO2 emissions from land clearing, fires, and decay

Heat and CO2 removal

Heat and CO2 emissions

Ice and snow cover

Shallow ocean

Land and soil biotaLong-term storageNatural 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 GreenlandIllustrated 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. 508

1982 2007

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

Some Output Methods for Removing CO2 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 CO2, CH4, and N2O by 2012

to levels of 1990• Trading greenhouse gas emissions among

countries• Not signed by the U.S.

What Can You Do? Reducing CO2 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 O3

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

CFCl3 + UV Light ==> CFCl2 + ClCl + O3 ==> ClO + O2

ClO + O ==> Cl + O2

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).