Is it warm in here or is it just me? An overview of global warming Matthew J. Essery

What to stay awake for: What is Global Warming? What is Global Warming? Causes of Anthropogenic Global Warming Causes of Anthropogenic Global Warming Is Global Warming Natural? Is Global Warming Natural? Recent History Recent History Effects of Global Warming Effects 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. Increasing concentrations of greenhouse gases in the atmosphere and the greenhouse effect. Agriculture, deforestation and the removal of large carbon sinks from the environment. 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.). 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) Industry loves to burn stuff and produce volatile chemicals (vapor forming at normal pressure and temperature) Internal combustion engine Internal combustion engine Power Plants Power Plants

How does the greenhouse effect work? Greenhouse gases allow high frequency radiation from the sun through them (visible light, ultraviolet light, etc.) 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. 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. 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 CO 2 Plants are a natural sink for carbon dioxide. Plants are a natural sink for carbon dioxide. Photosynthesis uses carbon dioxide Photosynthesis uses carbon dioxide 6H 2 O + 6CO > C 6 H 12 O 6 + 6O 2 Water + carbon dioxide -----> Glucose + Oxygen Sink means a storage place. Plants store carbon from the atmosphere by converting it into glucose. 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. 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 Agriculture Human habitation Human habitation Industrial and Commercial “development” 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. 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. 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. Some warming trends are slow, some are quick.

Ice Ages 150,000 y.a. Very Cold and Dry, Many Glaciers 150,000 y.a. Very Cold and Dry, Many Glaciers 130,000 y.a. Warmer and moister than today 130,000 y.a. Warmer and moister than today 110,000 y.a. Cold Again 110,000 y.a. Cold Again 100,000 y.a. Cooler than today but warming up 100,000 y.a. Cooler than today but warming up 95,000 y.a. Cold Again 95,000 y.a. Cold Again

More Ice Ages 90,000 y.a. Getting Milder 90,000 y.a. Getting Milder 70,000 y.a. Darn Cold and Glacial 70,000 y.a. Darn Cold and Glacial 60-25,000 y.a. Cooler and drier than today 60-25,000 y.a. Cooler and drier than today 25-15,000 y.a. Freakin’ Cold (Last Glacial Maximum) 25-15,000 y.a. Freakin’ Cold (Last Glacial Maximum) 14,500 y.a. Earth starts warming up rapidly 14,500 y.a. Earth starts warming up rapidly 13,500 y.a. Nearly as warm and moist as today 13,500 y.a. Nearly as warm and moist as today

Another Ice Age? 12,800 y.a. Sudden Cooling 12,800 y.a. Sudden Cooling 11,500 y.a. Sudden Cooling Suddenly Ends 11,500 y.a. Sudden Cooling Suddenly Ends 9,000 y.a Warmer and Moister than today 9,000 y.a Warmer and Moister than today 8,200 y.a. Sudden Cooling Again 8,200 y.a. Sudden Cooling Again 8,000 y.a. Warmer and Moister than today 8,000 y.a. Warmer and Moister than today 4,500 y.a. Mild Cooling. Similar to today 4,500 y.a. Mild Cooling. Similar to today

How do scientists know what temperature it was before written history? Ice cores. Ice cores. Bubbles trapped in ancient ice show trace gas composition. Bubbles trapped in ancient ice show trace gas composition. Isotopes in ice cores reflect temperature changes, vapor pressure and other climate data. Isotopes in ice cores reflect temperature changes, vapor pressure and other climate data. Huge wealth of info. trapped in ice. 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."

Swedish scientist Svante Arrhenius studies anthropogenic carbon dioxide in atmosphere. Swedish scientist Svante Arrhenius studies anthropogenic carbon dioxide in atmosphere. Small percentage changes in atmospheric carbon will have an effect several centuries later. Small percentage changes in atmospheric carbon will have an effect several centuries later. Good for plants. Good for vacations. 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. 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? Fossil Fuels cause carbon dioxide change? They knew this in 1950?

1965 1st government level publication about Global Warming (Roger Revell). 1st government level publication about Global Warming (Roger Revell). Most people don’t think humans can significantly change the atmosphere. 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 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 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 Congress discusses global warming Roger Revell reports on shrinking glaciers and ice melting Roger Revell reports on shrinking glaciers and ice melting NASA scientists predict that global warming should be observable in the 1990’s 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 Lots of countries start meeting to talk about Global Warming First Kyoto meeting First Kyoto meeting Senate says it will not ratify anything that might harm U. S. economy Senate says it will not ratify anything that might harm U. S. economy U. S. and Australia don’t sign Kyoto pact 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. Eight Arctic nations finish long term study on effects of Global Warming on the Arctic. The Arctic shrank almost 30% since 1970s. The Arctic shrank almost 30% since 1970s. Polar Bears will be extinct within yrs. Polar Bears will be extinct within yrs. 250 scientists from 8 nations worked on study. 250 scientists from 8 nations worked on study. Bush administration disagreed. Bush administration disagreed.

Effects of Global Warming

Melting Ice

Rising Seas Loss of coastal areas where most human habitation is. Loss of coastal areas where most human habitation is.

Extreme Weather Heat rising off of oceans causes much of the weather. Heat rising off of oceans causes much of the weather. Including hurricanes. Including hurricanes.

Massive ecosystem change Even slight changes in temperatures can lead to species extinction, changed migrations, behavioral changes, etc. Even slight changes in temperatures can lead to species extinction, changed migrations, behavioral changes, etc. Desertification of drier areas Desertification of drier areas Flooding of coastal areas. Flooding of coastal areas.