MODULE #2: Climate Change & Global Warming

…Science & Sources of Greenhouse Gas (GHG)

Emissions

Climate - the long-term “average weather” pattern of an area, including temperature, precipitation, and wind.

Weather - the short term state of the atmosphere at a specific time and place, including the temperature, humidity, cloud coverage, precipitation, wind, etc.

Climate Change - any long-term significant change in the “average weather” that a given region experiences.

These changes can be caused by dynamic processes on Earth, external forces including variations in sunlight

intensity, and more recently by human activities.Global warming - the increase in the average measured temperature of the Earth's near-surface atmosphere and

oceans since the mid-twentieth century, and its projected continuation.

Some useful definitions …

Is the Earth getting warmer?

Is the Earth’s climate changing?

Yes, it is constantly changing due to natural forcings (intensity of the sun, volcanic activity, etc.),

but more recently as a result of human activites.

20062006

The United States recorded its warmest year everwarmest year ever in 2006

2.2°F above the 20th Century ave.

20020077Source: NASA

Source: Union of Concerned Scientists

The Earth’s 20 Hottest Years on Record

Yes.

Why is the Earth getting warmer ?

• Thousands of peer-reviewed scientific research publications provide clear & convincing evidence for warming caused by humans (anthropogenic GHG emissions)

Source: IPCC Report: Summary for Policy Makers,

Climate Change 2001: The Scientific Basis

• Greenhouse Gas concentrations have increased dramatically since the industrial revolution. Prior to this, levels stayed relatively stable for thousands of years. Human activities are adding more GHGs to the atmosphere & boosting the Greenhouse Effect that we learned about in MODULE #1

in response to our actions!

There is There is overwhelmingoverwhelming evidence to evidence to show that our climate is changingshow that our climate is changing

• Temperature is increasing as

concentrations of CO2 (& other GHGs) increase in

Earth’s atmosphere

U.S. Industrial Revolution

begins

Graph courtesy of NASA. Data Source: Vostok ice core

data/NOAA

… … COCO22 levels have now reached levels have now reached unprecedented highs, and continue to rise unprecedented highs, and continue to rise

steadily every year …steadily every year …

HHow can we tell that the recent, rapid warming is ow can we tell that the recent, rapid warming is caused by human (anthropogenic) activity rather caused by human (anthropogenic) activity rather than natural cycles? than natural cycles?

If scientists only consider Natural climate forcings (like solar & volcanic activity), then computer models tell them Earth should’ve been cooling down over the past 30 years (gray line)… but that’s not what is happening in the real world (red line)

But when GHG emissions from human activities are included in the computer models, the results match what scientists are seeing

(temperature increasing)… so we are a key part of the equation!

Why is this problem uniquely caused by Why is this problem uniquely caused by us? us?

After all…After all…we humans live along with countless other species on planet Earth, and like all species … change our environment to a greater or lesser degree.… And change is inevitable.

…BUT the rate (and magnitude) of change we have caused since the industrial revolution is much too great for the natural cycles to maintain a balance!

As the American Geophysical Union recently concluded: "It is As the American Geophysical Union recently concluded: "It is scientifically inconceivable that - after changing forests into cities, scientifically inconceivable that - after changing forests into cities,

putting dust and soot into the atmosphere, putting millions of acres of putting dust and soot into the atmosphere, putting millions of acres of desert into irrigated agriculture, and putting greenhouse gases into the desert into irrigated agriculture, and putting greenhouse gases into the atmosphere - humans have not altered the natural course of the climate atmosphere - humans have not altered the natural course of the climate

system." system."

Let’s take a look at the major sources of GHG emissions in VermontVermont…

Can you guess which 2 sources below are responsible Can you guess which 2 sources below are responsible

for nearly ¾ of Vermont’s Greenhouse Gas for nearly ¾ of Vermont’s Greenhouse Gas Emissions?Emissions?

Transportation?Heating our

homes and businesses?

Agriculture?

Industry?

Landfills?Electricity

generation / use?

11%

(1- 5%)

3%

4% 6%

44% 27%

Transportation

Heating our homes &

businesses

Electricity

Industrial processes

Landfills / Waste Industrial fuel use

Agriculture

Vermont’s

Greenhouse Gas

Emissions

How does Vermont’s “emissions profile”

compare to the entire United States?

Residential / Commercial

Fuel Use9%

Landfills / Waste4%

Industrial Processes

8%

Industrial Fuel Use14%

Agriculture7%

Electrictiy32%

Transportation26%

Vermont

United States

GHG Emissions by Source

Category (2000)

How do these 2 pie charts differ?

Can you think of reasons why Vermont’s GHG

emissions profile looks different?

Please go on to MODULE #3 to learn about how GHG emissions are changing things around the globe…