Is it warm in here or is it just

me?An overview of global

warmingMatthew J. Essery

What to stay awake for:

What is Global Warming?Causes of Anthropogenic

Global Warming Is Global Warming Natural?Recent HistoryEffects of Global Warming

What is Global Warming?

In the 20th century the Earth’s average near surface air temperature has risen 1 degree Fahrenheit (0.6 degrees Celsius).

Stories of grandparents walking through feet of snow to get to school (up hill both ways) might be true. . .

General Scientific Opinion

Most of the warming during the last 50 years is due to

anthropogenic activities . . . HUMAN ACTIVITY.

Anthropogenic Causes of Global Warming

Increasing concentrations of greenhouse gases in the atmosphere and the greenhouse effect.

Agriculture, deforestation and the removal of large carbon sinks from the environment.

How do humans produce greenhouse gases?

Humans like to burn stuff. When organic (carbon and hydrogen containing molecules) are burned they release heat and carbon dioxide, water and any impurities (carbon monoxide, sulfure dioxide, etc.).

Industry loves to burn stuff and produce volatile chemicals (vapor forming at normal pressure and temperature)

Internal combustion engine Power Plants

How does the greenhouse effect work?

Greenhouse gases allow high frequency radiation from the sun through them (visible light, ultraviolet light, etc.)

The radiation hits the earth and is converted into heat.

Greenhouse gases absorb heat instead of letting it escape into space. The atmosphere heats up.

It’s like what happens in a greenhouse. . .

Plants and CO2

Plants are a natural sink for carbon dioxide.

Photosynthesis uses carbon dioxide

6H2O + 6CO2 ------> C6H12O6+ 6O2Water + carbon dioxide -----> Glucose + Oxygen

Sink means a storage place. Plants store carbon from the atmosphere by converting it into glucose.

Less plants = less carbon dioxide taken in which leads to more in the atmosphere which leads to more greenhouse effect.

Where did all the plants go?

Agriculture Human habitation Industrial and Commercial

“development”

“Growth for the sake of growth is the ideology of a

cancer cell.”

Edward Abbey

Climate is affected by

human action.Everything affects everything else.

Is Global Warming Natural?

Geologic history shows natural warming and cooling trends.

In the last 1,000,000 years, every 100,000 years or so there are cooling and warming periods.

Some warming trends are slow, some are quick.

Ice Ages

150,000 y.a. Very Cold and Dry, Many Glaciers

130,000 y.a. Warmer and moister than today

110,000 y.a. Cold Again 100,000 y.a. Cooler than today but

warming up 95,000 y.a. Cold Again

More Ice Ages

90,000 y.a. Getting Milder 70,000 y.a. Darn Cold and Glacial 60-25,000 y.a. Cooler and drier than

today 25-15,000 y.a. Freakin’ Cold (Last Glacial

Maximum) 14,500 y.a. Earth starts warming up

rapidly 13,500 y.a. Nearly as warm and moist as

today

Another Ice Age?

12,800 y.a. Sudden Cooling 11,500 y.a. Sudden Cooling Suddenly

Ends 9,000 y.a Warmer and Moister than

today 8,200 y.a. Sudden Cooling Again 8,000 y.a. Warmer and Moister than

today 4,500 y.a. Mild Cooling. Similar to

today

How do scientists know what temperature it was before written history?

Ice cores. Bubbles trapped in ancient ice show

trace gas composition. Isotopes in ice cores reflect

temperature changes, vapor pressure and other climate data.

Huge wealth of info. trapped in ice.

According to one geologist: “the earth's

climate is a capricious beast; instead of taking its threat

seriously, we have been poking it with a sharp stick."

1897-1904

Swedish scientist Svante Arrhenius studies anthropogenic carbon dioxide in atmosphere.

Small percentage changes in atmospheric carbon will have an effect several centuries later.

Good for plants. Good for vacations.

1950s

Geophysicist Roger Revelle, with the help of Hans Suess, demonstrated that carbon dioxide levels in the air had increased as a result of the use of fossil fuels.

Fossil Fuels cause carbon dioxide change? They knew this in 1950?

1965

1st government level publication about Global Warming (Roger Revell).

Most people don’t think humans can significantly change the atmosphere.

1977

National Academy of Sciences releases “Energy and Climate” study which recommends more studies and not to panic at the possibility of global warming

Carbon dioxide is identified as a major greenhouse gas. 2/3rds of CO2 increase is from fossil fuels. 1/3 is from forest clearing

1980’s

Congress discusses global warming Roger Revell reports on shrinking

glaciers and ice melting NASA scientists predict that global

warming should be observable in the 1990’s

1990’s

Lots of countries start meeting to talk about Global Warming

1997. First Kyoto meeting. 1997. Senate says it will not ratify

anything that might harm U. S. economy.

1999. U. S. and Australia don’t sign Kyoto pact.

2004

Eight Arctic nations finish long term study on effects of Global Warming on the Arctic.

The Arctic shrank almost 30% since 1970s.

Polar Bears will be extinct within 50-100 yrs.

250 scientists from 8 nations worked on study.

Bush administration disagreed.

Effects of Global Warming

Melting Ice

Rising Seas

Loss of coastal areas where most human habitation is.

Extreme Weather

Heat rising off of oceans causes much of the weather.

Including hurricanes.

Massive ecosystem change

Even slight changes in temperatures can lead to species extinction, changed migrations, behavioral changes, etc.

Desertification of drier areas Flooding of coastal areas.