Transcript Global Climate Change: Mitigation - Florida International University

Equal Time for President Bush
The IPCC 2007 report
• Global atmospheric
concentrations of carbon
dioxide, methane and nitrous
oxide have increased markedly
as a result of human activities
since 1750 and now far exceed
pre-industrial values determined
from ice cores spanning many
thousands of years.
• The global increases in carbon
dioxide concentration are due
primarily to fossil fuel use and
land-use change, while those of
methane and nitrous oxide are
primarily due to agriculture.
11 of the past
12 years
are the
warmest
since
reliable
records
began
around
1850
• Global warming is "very
likely" caused by man,
meaning more than 90
percent certain. That's the
strongest expression of
certainty to date from the
panel.
• If carbon dioxide
concentrations in the
atmosphere reach twice
their pre-industrial levels,
the report said, the global
climate will probably warm
by 3.5 to 8 degrees. But
there would be more than
a 1-in-10 chance of much
greater warming, a
situation many earth
scientists say poses an
unacceptable risk.
• A snow-maker created snow on the
slopes of Parsenn in Davos,
Switzerland in February. Many
attribute this winter's low snowfall to
global warming.
• But if the world does get greenhouse gas
emissions under control _ something
scientists say they hope can be done _ the
best estimate is about 3 degrees
Fahrenheit.
• Sea levels are projected to rise
7 to 23 inches by the end of
the century. Add another 4 to 8
inches if recent, surprising
melting of polar ice sheets
continues.
• Sea level rise could get worse
after that. By 2100, if nothing is
done to curb emissions, the
melting of Greenland's ice
sheet would be inevitable and
the world's seas would
eventually rise by more than
20 feet, Bindoff said.
That amount of sea rise would take centuries, said Andrew Weaver of
the University of Victoria in Canada, but 'if you're in Florida or
Louisiana, or much of western Europe or southeast Asia or
Bangladesh ... or Manhattan ... you don't want that,' he said.
• The debate over whether global warming
is happening and that it is anthropogenic is
over (fierce resistance from petroleum
companies is now past) but now the
debate is “what does it cost to reduce
carbon emissions to certain levels that will
prevent the worst harm?)
The Stern Report-2006
• The economic model used in the Stern Review finds that the
damages from business as usual would be expected to reduce GDP
by 5% based on market impacts alone, or 11% including a rough
estimate for the value of health and environmental effects that do
not have market prices (“externalities,” in the jargon of economics).
If the sensitivity of climate to CO2 levels turns out to be higher than
the baseline estimates, these losses could rise to 7% and more than
14%, respectively.
• A disaggregated description of impacts by sector and region is
generally in agreement with these numbers, according to the
Review. Stern speculates that an adjustment for equity weighting,
reflecting the fact that the impacts will fall most heavily on poor
countries, could lead to losses valued at 20% of global GDP.
• These figures are substantially greater than the comparable
estimates from most economists
• These damages can be largely avoided, at much
lower cost, through emissions reduction (or
“mitigation,” in the jargon of climate change).
Stabilization at 500–550 parts per million (ppm)
of CO2-equivalent7 in the atmosphere would
avoid most, though not all, of the “business as
usual” damages.
• Both direct estimates of mitigation costs and a
review of results from many different models
suggest that stabilization at this level would cost
about 1% of GDP. Stabilization below 450 ppm,
according to Stern, is no longer feasible
• First, what is the maximum atmospheric concentration of CO2 at
which unacceptable climate outcomes can be ruled out with a high
degree of confidence?
• • Second, what is the least-cost strategy for stabilizing at that
concentration?
• The first question is the essence of a precautionary approach to
policy, in a context of complex and uncertain scientific information. It
involves several difficult, but not impossible judgments: about the
(probabilistic) link between CO2 levels and climate outcomes; about
which climate outcomes are unacceptable; and about how high a
degree of confidence is required that we can avoid those outcomes.
What To Do?
• Adaptation-Favorite argument of neoclassical
economists.
• They believe that large uncertainties in climate
projections make it unwise to spend large sums trying to
avert outcomes that may never materialize.
• They believe that human systems can adapt to climate
change much faster than they occur.
• They maintain that while doubling of CO2 will take place
over the next century, financial markets adapt in minutes,
labor markets in several years, and the planning horizon
for significant economic and technological change is at
most two or three decades.
• But what are the risks of “large, abrupt, and unwelcome
shifts in climate?”
Mitigation
• “curtailing the greenhouse gas buildup to prevent,
minimize, or at least slow global warming” (harper, p.
97)
•
•
•
•
•
•
White surfaces and vegetation.
Residential water heating.
Residential space heating
Residential and commercial lighting.
Industrial energy management
Fuel efficiency
Transportation Energy Management
• Vehicle efficiency
• Alternative fuels (ethanol from biomass,
solar-hydrogen)
• Transportation demand management
• Electricity and fuel supply
Carbon Tax?
• tax on energy sources which emit carbon
dioxide into the atmosphere. It is an
example of a pollution tax, which some
economists favor because they tax a "bad"
rather than a "good" (such as income).
Because a carbon tax addresses a
negative externality
Equity issue that Harper raises (p.
101)
•
the regressivity of a carbon tax could be minimized or eliminated by allocating the tax
revenues to benefit the less affluent.
•
Wealthier households use more energy, on average — they drive and fly more, have
bigger (and sometimes multiple) houses, and buy more products that require energy
to manufacture and use. Most carbon tax revenues will therefore come from families
of above-average means, as well as corporations and government.
•
This creates a basis for progressive tax-shifting: transferring a portion of the tax
burden from regressive taxes such as the payroll tax (at the federal level) and the
sales tax (at the state level) onto pollution and pollution-generating activities.
•
Another progressive approach in the United States is to rebate the carbon tax
revenues equally to all U.S. residents — a national version of the Alaska Permanent
Fund, which once a year sends identical checks to all state residents from the state’s
North Slope oil royalties. Because income and energy consumption are strongly
correlated, most poorer households would get more back in rebates or tax savings
than they would pay in the carbon tax.