GLOBAL WARMING 101
Greenhouse Effect:
The greenhouse layer
is a layer of gases in the atmosphere. It allows the sun’s heat energy to enter the atmosphere,
keeping some of the heat inside, and allowing some of the heat to escape back into space - acting like a blanket
around the Earth. The greenhouse layer is something that nature intended and it’s what makes our
planet uniquely able to sustain life. For example, the greenhouse gases surrounding
Mars are almost non-existent, so the temperature there is far too cold for life. Venus has a very thick layer of
greenhouse gases, so the temperature is way too hot for life to survive. Earth is sometimes referred to as the
“Goldilocks planet” because the temperatures here have been just right - historically that is!
The problem today is that the greenhouse layer is being thickened by large amounts of human-caused carbon dioxide and
other heat-trapping gases.
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Carbon Dioxide Levels:
Natural sources of greenhouse gases existed long before people played a central role. Nature
kept this system in balance by absorbing some of the gases through forests and oceans. BUT about 200-300 years ago,
humans commenced the Industrial Revolution. This “industrialized” way of life meant that more coal, natural gas, and oil was burned to power engines and factories. With every increase in this type of
technology, humans have added more and more greenhouse gases to the atmosphere. These gases are being
released much more quickly than they can be absorbed, especially when coupled with deforestation and declining
ocean health. Pre-industrial levels of carbon dioxide equaled 280 parts per million (ppm).
Today, carbon dioxide levels in the atmosphere equal 380 ppm - well above anything measured within a
400,000 year record. Most of this growth from pre-industrial levels has happened since the 1970s.
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Impacts:
Research
has shown a strong correlation between carbon dioxide levels and temperature.
The increased amount of greenhouse gases in the atmosphere is creating a thicker blanket around the Earth,
thus trapping more heat and causing global surface and oceanic temperatures to rise. From 1920 to the present,
the earth’s average surface temperature has increased by 1.4°F. According to the National Academy of
Sciences, this is the largest global temperature rise in at least the last 2,000 years. As a result,
changes are occurring in the timing and length of seasons, the frequency of precipitation and the proportion
of water that is frozen in ice caps and glaciers. If these changes continue unabated it will lead to a disruption
of our food supply, the displacement of millions of people living in coastal lowlands or near growing deserts,
the intensification of storms, floods and droughts and the extinction of countless species.
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Additional Sources:
Visit the Pew
Center for Global Climate Change site to get in depth information and read various reports on the causes,
effects and solutions to Global Warming.
Click here for the Citizen’s
Climate Briefing - What every person needs to know about Global Warming
LOCAL IMPACTS
Climate change is already disrupting Washington’s economy, communities and environment.
During the 20th century, the Puget Sound region warmed by 2.3°F,
significantly more than the global average. It is projected that this trend will continue with
additional warming of
1.8 to 3°F in the next 30 to 40 years
We have already observed a 30% overall decline in the Lower Cascades spring snow
pack .
We rely on mountain snow packs for our summer stream flows. Changing streams and
runoff patterns could lead to declines in salmon populations beyond what we have seen already.
In fact, by 2050, the Columbia River is projected to have 30-50% less water during summer
months .
Milder winters followed by hotter, drier summers could impact the farming community and result in
more forest fires (the number of large wildfires in Washington State has increased from an average
of 6 per year in the 1970s to 21 per year today ).
More precipitation falling as rain rather than snow would lead to more flooding and landslides.
Coastal communities are threatened by rising sea levels. A sea level rise of 6 feet would put
parts of I-5 around Mount Vernon and Marysville under water and flood the Everett area as far inland as
Snohomish. Preventative action would be required to protect the major industrial ports of Seattle and Tacoma.
Need some good news? Individuals and governments all around the state are taking action to combat climate change:
- Bellingham became the #1 EPA certified Green Power Community in the nation in early 2007, and
received the EPA's Green Power Purchaser Award later that year for making a significant purchase
of green energy - now over 11% of electricity comes from renewable sources!
- In February 2007, Governor Gregoire signed an
executive order
establishing goals for reductions in climate pollution, increases in jobs, and reductions in expenditures on
imported fuel. In January 2008, the state legislature adopted these goals into law.
- The federal government may not have signed the Kyoto Protocol, but 31 local governments in Washington have adopted policies and implemented measures to achieve reductions in greenhouse gas emissions through the Cities for Climate Protection Campaign (along with 430 other communities in the U.S.) as of May 2008.
- Research by the city of Bellingham shows that the city has one of the highest per capita hybrid car ownership
rates in the nation, three times the rate of Seattle.
- Washington State has already taken action to cut emissions by 20% by 2050. To learn more about the
state government’s response to climate change,
click here.
- Washington State is collaborating with the Governors of Arizona, California, New Mexico, Oregon, British Columbia, Manitoba, Montana, Quebec and Utah on the Western Climate Initiative (WCI). WCI is currently identifying, evaluating and implementing collective and cooperative ways to reduce greenhouse gases in the region.
- You’re next on the list! Click here to see how you can be a part of the solution.
- Visit the Community Spotlight page for more cool examples from the region.
For additional information about climate change in our region, visit the
Washington State Department of Ecology or the Northwest Clean Air Agency
climate change sites.
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