global change unit chapter 9: sustaining biodiversity: the species approach chapter 19: climate...

Global Change Unit

Chapter 9: Sustaining Biodiversity: The Species Approach

Chapter 19: Climate Change and Ozone Completion

Chapter 9: Sustaining Biodiversity - The Species

Approach

Extinction

Background extinction - Continuous low level extinction

Extinction rate - number of species that go extinct during a time period (%)

Extinction is natural, but human activities are destroying and degrading biodiversity causing premature extinctions.

Endangered and Threatened Species

Endangered species have so few survivors that the species could soon become extinct.

Threatened species are abundant in their natural range but could become endangered because of declining numbers.

Endangered

Species

Why prevent extinction?Instrumental value - usefulness to us in

providing ecological and economic services.

Intrinsic or existence value - species have the right to exist.

HIPPCO: The greatest threat to species

H: Habitat destruction, degradation and fragmentation

I: invasive speciesP: population and resource useP: pollutionC: climate changeO: overexploitation

Invasive Species

Accidentally or intentionally introduced

Often have no natural predators or competitors.

Invasive Species

Prevention of new invasive species is important.

Overexploitation

Illegal killing, capturing and selling of wild species.

Demand for bushmeatExotic pets

Protecting Species

U.S. Endangered Species Act - Identify and protect endangered species in the U.S. and abroad. Based on biological factors alone, which makes it controversial.

ESA forbids projects that could jeopardize and endangered species or threaten its habitat.

Protecting Species

Establish wildlife refuges and other protected areas.

Gene banks, botanical gardens, and wildlife farms

Zoos and Aquariums

Chapter 19: Climate Change and Ozone Depletion

The History of Global WarmingOver earth’s 4.5 billion year history its

climate has been altered by volcanic eruptions, solar input, moving continents, meteors etc.

Glacial and interglacial periods have marked the past 900,000 years.

Global Temperature

The Greenhouse Effect

The greenhouse effect warms the lower atmosphere in the surface of the earth.

How? Water vapor, carbon dioxide, methane and nitrous oxide (all make up 1%) molecules kinetic energy increases when energy is reflected by the earth into the atmosphere. The energy is then reflected back to the surface in the form of infrared energy.

Greenhouse Gases

Humans emit A LOT of greenhouse gases into the atmosphere.AgricultureDeforestationBurning fossil fuels

In the past, increases in greenhouse gases have coincided

with increased

global temperature.

Greenhouse GasesCO2 levels have increased from 228 ppb to 384

ppb (59%) in the last 275 years from mostly burning fossil fuels.

Methane emissions are caused by: dams, landfills, farm animals, extracting fossil fuels, melting permafrost.

N2O levels have risen by 20% during the last 275 years mostly due to increased use of nitrogen fertilizers.

Predicting the Effects of Global Warming is Complicated

Understanding Global Warming

Hotter Sun? Probably not, as the stratosphere has been cooling.

Oceans absorb carbon dioxide, but as they warm, they cannot hold as much and release CO2 back into the atmosphere (oops).

Understanding Global Warming

Increased Cloud Cover could reflect the sun and cool the earth or keep the energy near the surface (like a greenhouse gas). Depends on cloud type.

Air pollution - aerosols (suspended microscopic droplets and particles) can hinder or increase cloud formation.

Effects of Global Warming

Problem: The change in global temperature is occurring rapidly.

Effects of Global Warming

Ice and Snow Are Melting

Sea Levels are Rising

Permafrost is Melting

There is More

Changing Ocean Currents

Extreme weather in some areas

Biological ranges are being altered and biodiversity threatened.

Threats to Human Health

Global Warming and Biodiversity

Slowing Climate Change

Problems:Global IssueEffects are long lastingLong-term political issueImpacts of Climate Change are not spread

evenlySolutions could disrupt economies

Slowing Climate Change

Improve energy efficiencyShift from non-renewable fossil fuels to

a mix of renewable sources.Stop cutting forests (especially tropical)Capture and store as much CO2 as

possible.

How can this be done?

Slowing Climate Change

Carbon Capture and Storage

CCS involves removing CO2 from smokestacks and storing the elsewhere like abandoned coal beds or gas fields.Expensive power plantsHow can CO2 be captured

Requires a lot of energySupports continued use of coal

Governments and Climate Change

The cost of damages from global warming and the cost to slow it down are debatable.

Governments can regulate CO2 and CH4 pollutants, use carbon or energy taxes instead of property or income tax.

The Kyoto Protocol

In 1997, 161 nations met in Japan to negotiate a treaty to slow climate change.

174 of the worlds 194 nations ratified the treaty that required developed countries to reduce greenhouse gas emissions.

Allows for trading of greenhouse gas emissions. (caps set high)

Some are Making a Change

China and India are investing in sustainable development.

U.S. Companies are reducing greenhouse emissions to save money.Wal-Mart saves $34 million a year by

using cfl’s and auxiliary power units for shipping trucks.

Ozone Depletion

Seasonal thinning of the ozone layer caused by: Chlorofluorocarbons - air conditioners,

fridges, aerosol cans, cleaners, fumigantsHydrobromoflurocarbons - fire extinguishersMethyl bromide - fumigantHydrogen chloride - space shuttlesVarious chemicals from cleaning solvents

Ozone Depletion is Bad

More UV-A and UV-B radiation will reach the earth’s surface resulting in more cataracts, sunburns and skin cancer.

Increased radiation could impair or destroy phytoplankton.

Reversing Ozone DepletionStop producing all ozone-depleting

chemicals. (60 years to recover)

Warming the troposphere makes the stratosphere cooler which slows down ozone repair.

Copenhagen Protocol (1992) - 191 countries agreed to phase-out key ozone-depleting chemicals.