Climate Change and Ozone Loss

Chapter 18

“We are embarked on the most colossal ecological experiment of all time – doubling the concentration in the

atmosphere of an entire planet of one of its most important gases – and we really have little idea of what

might happen.”

Paul A. Colinvaux

Key Concepts

How does the Earth’s climate fluctuate

What factors affect climate

What are the possible effects of global warming

What can humans do about potential climate change

How are human activities affecting the ozone layer

What can humans do about changes in the ozone layer

Past Climate ChangePast global temperatures

Recent trends in global temperatures

Fig. 18-2 pg 447

The Natural Greenhouse Effect

Greenhouse effect

Greenhouse Gases

Climate Change and Human Activities

Increased use of fossil fuels

Deforestation

Global warming

Melting icecaps and glaciers

Coral reef bleaching

Projecting Future Changes in Earth’s Climate

Climate models (see Spotlight p 457)Apparent influence of human activitiesCould be natural changes

Fig. 18-11 p. 455Fig. 18-11 p. 455

Factors Affecting Changes in Earth’s Average Temperature

Changes in solar output

Changes in Earth’s albedo

Moderating effect of oceans

Clouds and water vapor

Air pollution

Fig. 18-13 p 458

Some Possible Effects of a Warmer World

Fig. 18-16 p 461

Solutions: Dealing with the Threat of Climate Change

Do nothingDo more researchAct now to reduce risksNo-regrets strategy

Options:

Fig. 18-20 p 466

Removing CO2 From The Atmosphere

Treeplantation

Coalpower plant

Tanker deliversCO2 from plantto rig

Oil rig

Crop field Switchgrassfield

Spent oil reservoir isused for CO2 deposit

CO2 is pumpeddown to reservoir through abandoned oil field

Abandonedoil field

CO2 is pumped downfrom rig for Deep ocean disposal

= CO2 deposit

= CO2 pumping

Fig. 18-21 p 467

Reducing Greenhouse Gas Emissions

Ozone Depletion in the Stratosphere

Fig. 18-26, p 473

Terrestrial life

Reduce sunburn

Prevents tropospheric ozone

Importance of Ozone

Ozone Depleting Chemicals

Chlorofluorocarbons (CFC’s)

Halons

Methyl bromide

Carbon tetrachloride

Methyl chloroform

Hydrogen chloride

Seasonal Thinning at the Poles

Ozone thinning (hole)

Fig. 18-30 pg. 475

Polar vortex

Reasons for Concern

Increased incidence and severity of sunburn

Increase in eye cataracts

Increased incidence of skin cancer

Immune system suppression

Increase in acid deposition

Lower crop yield and decline in productivity

Solutions:Protecting the Ozone Layer

CFC substitutes

Technofixes

Montreal Protocol

Fig. 18-33 pg. 479