Global Warming and Ozone Loss

Study Guide

What has caused climate change in the past?

Natural phenomena such as: Volcanic eruption, solar cycles, continental drift, and meteor impact.

Evidence of Climate Change?

Ice cores, tree rings, direct measurements from temperature data (1870s), satellite data (1960s), and CO2 measurements (1958)

Ice cores

Gases trapped inside ice cores that reveal information about past atmospheric composition.

Tree Rings (Dendrochronology)

Studying the width of tree rings indicates the kind of growing season. Wider tree rings = healthy growing conditions. Narrower tree rings = poor growing conditions.

Major Greenhouse Gases (Least Powerful/More Concentrated to Most Powerful/Least Concentrated)

CO2, CH4, N2O, and CFCs

CO2

Caused by burning fossil fuels, deforestation, and clearing land. Warming power of 1.

CH4

Caused by cow burps, rice paddies, landfills, and leaking natural gas. Warming power of 25-100.

N2O

Caused by bacterial breakdown of fertilizer. Warming power of 300.

CFCs

Caused by refrigerants, aerosol propellants, and packing peanuts. Warming power of over 1000.

Current Evidence for Climate Change?

Rising average temperature increase (1.1° C/ 1.9° F) , Melting ice caps/sea ice, permafrost, and primarily rising sea level from thermal expansion = environmental refugees.

Other Factors that Affect the Earth’s Temperature

The ocean, cloud cover, and global wind circulation cells.

How does the Ocean Play a Major Climate Role?

Absorbs and releases heat and CO2. As well as distributing said heat.

How Can Cloud Coverage Affect the Earth’s Temperature?

Altostratus clouds can cool the earth and cirrus clouds can warm it.

What are Global Wind Circulation Cells?

Distributors of heat and moisture that when disrupted can have a major global impact.

What is Soil’s Relation to Warming?

Changes in temperature and rainfall and resulting erosion potential can impact productivity of land.

Melting ice caps and tundra can…

Release methane, creating a positive feedback loop. This can occur warming in swamps and marshes which reduce biodiversity.

Melting Ice Timeline

Less Ice, more land exposed, less albedo, more heat absorbed, more warming, and finally the melting of ice.

Movement of … = more environmental refugees

Disease tropical to temperate areas

Loss of … from Habitat Loss

Marine species (Sea level rise, change in photic zone. Coral Bleaching)

How Do We Prevent Global Warming?

Prevention by stop producing culprit gases and clean up. Specifically, sequestering CO2 (Prevention) by planting a tree or CCS, carbon capture and storage.

Kyoto Protocol (1997) and Paris Accord (2016)

An agreement to reduce GHG emissions

What Can an Individual Do to Reduce CO2?

Bike/walk/carpool, adjust thermostat, energy efficient lighting, eat less or no meat, plant a tree, insulate/seal house, and wash clothes on warm/cool water.

What Layer of the Atmosphere Does the Ozone Layer occur?

The stratosphere, through O+O2 —UV—> O3

What is the Role of Ozone?

Filters UV Radiation and allows life we know it to exist.

What are the positives of CFCs?

Cheap, nonflammable, noncorrosive, nontoxic, and work well

What are the negatives of CFCs?

Destroys the ozone layer and an extremely powerful GHG

Ozone Depletion Process

When a CFC molecule in the stratosphere interacts with UV energy, a chlorine atom is released, which attacks ozone and destroys it. Chlorine is constantly regenerated and cycle continues until natural dissipates after a couple of decades.

CFC —UV—> CFC + Cl

Cl + O3 ——> ClO + O2

ClO + O ——> Cl + O2

Ozone Depletion Timeline

Jun-Aug, swirling polar vortex forms ice crystals that collect CFCs in vortex. Light returns in Oct, Ozone depletion reactions begin. Vortex breaks up in Dec-Feb, spewing ozone depleted air over the S Hemisphere = more UV to reach Earth’s surface.

Results of Ozone Depletion

Human Health (Skin cancer and cataracts), Plants (kills phytoplankton and lowers crop yield), and Air pollution (Photochemical smog)

How Do We Protect the Ozone Layer?

Eliminate ODCs and use substitutes such as HFCs

Montreal Protocol (1987) and Copenhagen Protocol (1992)

Treaties to eliminate the broad use of CFCs and ODCs