Transcript ESC 110: Global Climate Change: Facts & Fiction

ESC 110: Global Climate Change:
Facts & Fiction
Olympic rain forest doomed by global warming, report fears
Friday, February 8, 2002
By ROBERT McCLURE
SEATTLE POST-INTELLIGENCER REPORTER
Olympic rain forest isn't going away
Tuesday, February 26, 2002
DAVID L. PETERSON
RESEARCH SCIENTIST
Chapter 18 of text
GCC: Fact or Fiction
From your text: One of “the two
most immediate global
environmental threats humans face
is climate change caused by
greenhouse gases. This is caused
by the introduction of large
quantities of human-produced
gases into the atmosphere.” Are
these statements true? Does
everyone agree with them?
GCC: Givens
• Climate will change (because it has changed).
• Carbon dioxide levels are increasing in the
atmosphere
• The greenhouse effect is real (and important).
GCC: Questions
• How will the climate change and how much
will the climate change?
• Is the change natural or due to human
activities?
GCC: Greenhouse effect
• The greenhouse effect is caused by traces
gases in the atmosphere (water vapor,
carbon dioxide, methane, others)
• 1.4oF
• -17oC
• 59oF
• 15oC
2
• “Steady”
GCC: Changes in a greenhouse gas
GCC: Changes in a greenhouse gas
Increasing
Pattern
Biological activity
Human activity
GCC: Why is the greenhouse gas
changing? Human activity?
GCC: Consequences of Increased CO2
•
•
•
•
•
•
If CO2 has increased,
CO2 is a greenhouse gas and
Greenhouse gases warm the earth then
The earth should be warmer! Is it?
Yes
But
–
–
–
–
Surface
Trend
Solar
Aerosols
GCC: Present Temperature Change to
Historical
GCC: Present Temperature Change to
Historical
GCC: Climate Change: Predictions
MODEL
Know CO2 will continue to increase
Greenhouse effect should increase
Therefore temperature should increase
Four responses:
• A disaster
• The best news ever
• Do not know enough
• Natural cycles dominate
GCC: Implications on Plants
Species responses
Disturbance regimes
GCC: Implications on Plants: How do
we know?
GCC: Let’s assume we need to do
something, then what?
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•
•
•
Conservation
Alternative energy sources
Consumption
Regulate carbon dioxide emissions (Kyoto
Protocol)
• Carbon tax
• Use plants (trees) to take up or sequester the
carbon.
GCC: Solutions with plants
Could the earth’s biological systems accumulate
sufficient CO2 to balance emissions?
Anthropogenic release
+6.3 - +7.0
Net uptake by terrestrial vegetation
-0.7
Net uptake by the oceans
-2.3
Gain by the atmosphere
+3.3 - +4.0
1 Giga ton = if the carbon was solid, 81 Safeco Fields and if the
carbon was in the form of pure carbon dioxide, 392 Safeco Fields
GCC: Solutions with plants
• To balance the net gain of 4 Gt of carbon by
the atmosphere through planting young
forests, and,
• assuming an increase in production of 5 t ha-1
over the vegetation replaced, e.g., replacing
an older, natural forest with a forest crop,
• requires over 109 hectares of young forest,
~14 times the size of Washington State.
• Balancing the CO2 input from the US alone
would require an area ~3 times Washington
State ( ~1.2 times the size of California)
Global Climate
Change: Where are
we?
Olympic rain forest doomed by
global warming, report fears
Friday, February 8, 2002
Human contribution
Climate has changed
Climate change has consequences
Involved in a massive experiment
You are the observers of this
experiment.
You will need to address when
something should be done & how.