1. Our Changing Atmosphere
The Earth’s surface temperature has risen by about 1 deg. F. in the past century
Strong evidence suggests that warming is attributable to human activities

2. Greenhouse Effect Energy from the sun drives the earth’s climate
Greenhouse effect maintains livable temperature
Problems arise when concentrations increase

3.
co2 experiment

4. Our Changing Atmosphere
Humans are emitting more greenhouse gases into the atmosphere
Cars, trucks, home and business heating/cooling, and power factories(40%) are responsible for about 98% of US carbon dioxide emissions
… leads to “Enhanced” Greenhouse Effect…

5. Since the industrial revolution, greenhouse gases have increased by:
Carbon Dioxide 30%
Methane %
Nitrous Oxide 15%

6. Our Changing Climate
Global mean surface temperatures have increased deg F since late 19th century
The 20th century’s 10 warmest years have occurred in the last 15 years of the century

7. 420,000 years of Ice core data
… support the link between CO and Temperature

10. So what happens to the Earth?
Climate is a complex conundrum, with many inter-related factors…
Thus we use computer models to make predictions:
Rise in sea levels (due to volumetric expansion of warmer water V=VoβΔT, and the melting of land ice in Greenland, Antarctica, glaciers

13. So what happens to the Earth?
Weather changes (difficult to predict): equatorial regions get hotter, Northern hemisphere gets wetter,

14. Industrialized World…
Is 33% of world’s population
Uses 80% of world’s total energy

15. You and I (in the USA): Are 5% of worlds’ population
Use 33% of worlds’ total energy

16. Compared to India: is 15% of world’s population
Uses 1% of worlds’ total energy

17. Compared to India:
USA uses more energy just for air conditioning than…
India uses for ALL of their energy purposes (5 times more people)

18. Who’s most responsible?
Emissions per American have increased about 3.4% between 1990 and 1997
Most of these emissions, about 82%, are from burning fossil fuels to generate electricity and power our cars
Remaining emissions are from methane from wastes in our landfills, raising livestock, natural gas pipelines, and coal

19. International Effort
1988: IPCC formed (Intergovernmental Panel on Climate Change) Its role is to openly and objectively assess the latest scientific, technical and socio-economic literature produced worldwide relevant to the understanding of the risk of human-induced climate change, to provide the decision-makers and others interested in climate change with an objective source of information about climate change on a comprehensive, objective, open and transparent basis
: Kyoto Protocol Treaty(ratifying countries committed to reduce greenhouse gases to 5% below 1990 levels by countries ratified… not US, Australia)

20. International Effort
2005 APPCDC (Asia-Pacific Partnership on Clean Development and Climate)… non-treaty agreement amongst the 6 countries that account for 50% of gg emissions… to develop and share technology to reduce global warming Australia, Canada, India, Japan, the People's Republic of China, South Korea, and the United States

21. Use less energy (and use renewables) Capture CO2 (plant trees!)
“average citizens can make valuable contributions by making small lifestyle changes without waiting for governments to act”:
Use less energy (and use renewables)
↑ efficiency of electric power production
Heat homes with excess power station heat,use hybrid/electric vehicles,
Capture CO2 (plant trees!)

23. What Is Known For Certain
Uncertainties
What Is Known For Certain
Human activities are changing the composition of the atmosphere
Carbon Dioxide, Methane, and Nitrous Oxide have increased as a result of human activities
Greenhouse gases trap heat in the earth’s atmosphere and tend to warm the planet
The key greenhouse gases emitted by human activities remain in the atmosphere for decades to centuries
A warming trend of about 1 deg. F has been recorded since the late 19th century

24. What Is Likely, But Not Certain
Uncertainties
What Is Likely, But Not Certain
What extent has the human-induced accumulation of greenhouse gases are responsible for the global warming trend
For instance, scientific understanding of other factors are not know, such as natural climatic variations, changes in the sun’s energy, and the cooling effects of pollutant aerosols is incomplete

25. What Are The Big Unknowns
Uncertainties
What Are The Big Unknowns
Projecting the impacts to Health, agriculture, water resources, forests, wildlife and coastal areas in regional areas is very difficult
Large–scale areas are more suited to global warming computer models
Links to Global Warming and El Nino

26. What Are the Big Unknowns Contd…
Uncertainties
What Are the Big Unknowns Contd…
How much warming will occur?
How fast will this warming occur?
What are the potential adverse and beneficial effects?
These uncertainties will be with us for some time, perhaps decades

27. Summary There are many unknowns to global warming
There are some things that are known however
The science points to continued warming
Nothing is certain