Water vapor is also a greenhouse
gas, but its concentration in the atmosphere
is not subject to direct human
influence. The amount of water vapor
in the atmosphere is controlled by the
temperature, because the capacity to
hold water vapor increases with rising
temperature. Thus, water vapor acts as
an amplifier, boosting the warming
effects of other greenhouse gases.
HOW DO WE KNOW THAT CLIMATE
CHANGE IS REALLY HAPPENING?
|
Imagine getting your winery's
Board of Directors or management
team to read a document summarizing
the highly technical and complex
details of your operations, and their
significance to your bottom line. Now
imagine them going through an
explicit and lengthy process to agree to
EVERY SINGLE WORD in the document.
This is the process used by the
panel convened by the world's governments
to assess knowledge about
climate change (the Intergovernmental
Panel
|
on Climate Change, or IPCC;
www.ipcc.ch/) about once every
six years.
The cumulative contributions of
this international team of expert scientists,
including four major assessments
andmany special reports, earned them
a share of the Nobel Peace Prize in
2007. IPCC scientists read and interpret the vast published literature on
climate change and write a comprehensive,
balanced portrayal of the current
scientific understanding.
|
Figure IV. Projected warming in global annual average temperatures from multiple climate models for a range of scenarios of emissions of
greenhouse gases. Yellow line represents a case where no further greenhouse gases were added to the atmosphere. Gray bars to the right
represent the range of 66% probability, with solid lines within each bar representing the IPCC "best estimate." Colored shading represents ±1
standard deviation.
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