Coping with global warming:
Fifteen
alternative strategies (Pacala & Socolow)
We already have the needed technology
“Humanity
already possesses the fundamental scientific, technical, and industrial
know-how to solve the carbon and climate problem for the next half-century. A
portfolio of technologies now exists to meet the world's energy needs over the
next 50 years and limit atmospheric CO2 [carbon dioxide] to a
trajectory that avoids a doubling of the preindustrial concentration. Every
element in this portfolio has passed beyond the laboratory bench and
demonstration project; many are already implemented somewhere at full
industrial scale. Although no element is a credible candidate for doing the
entire job (or even half the job) by itself, the portfolio as a whole is large
enough that not every element has to be used.”(Pacala and Socolow, Science, Aug.
13, 2004, p.968-972).
In
their Science article, Pacala and Socolow have calculated, for each of
fifteen strategies, what it would take to get a 1 gigaton of carbon emission
reduction per year by 2054 from each of them. He calls this unit a “wedge”.(A gigaton is a
billion tons.)
To
avoid the worst climate change, climate scientists are currently proposing a
goal of no more than 500 parts per million (ppm) of atmospheric CO2 by
2054.At present we are at about 380 ppm and a global emission of about 7
gigatons of carbon per year.Under conditions of business as usual (BAU), where
the world doesn’t do much about global warming, we are slated to double that
and reach about 14 gigatons emissions per year in 2054.To achieve our desired
goal of 500 ppm CO2 concentration by 2054, we need to hold
emissions near the present level of 7 gigatons of carbon per year for the next
50 years. Adopting any seven of Pacala and Socolow’s “wedges” (1 gigaton
reduction from each) will get us there they calculate.To read the full details
of their proposals click here.
1.
Increase fuel
economy for 2 billion conventional cars from 30 to 60 mpg.
2.
Decrease yearly
car travel for 2 billion 30 mpg cars from 10,000 to 5,000 miles.
3.
Cut carbon
emissions by one-fourth in buildings and appliances projected for 2054.
4.
Introduce carbon
capturing technology (CCS) at 800 coal-fired power plants that produce a
gigawatt of electricity (75% of the total).
5.
Substitute 700
gigawatts of conventional coal produced power with new nuclear produced plants
-- twice the current nuclear capacity
6.
Add 2 million
1-megawatt windmills to substitute for coal power– 50 times the current
capacity – would occupy the equivalent of 3% of the area of the U.S.
7.
To get wind power generated
electricity to produce hydrogen for fuel-cell cars in place of gasoline in
hybrid cars add 4 million 1-megawatt windmills (compare with no.6)
8.
Solar
(photovoltaic) power that will replace coal generated power add 2000 gigawatts
of solar plants. This would require
8,000 square miles of land in 2054.
9. Biofuels
such as ethanol. If the ethanol was
carbon-free and produced from crops that were grown in addition to food crops,
an ethanol “wedge” would require 618 million acres by 2054 to grow the crops,
or one-sixth of the world’s cropland.
(Note: world population is estimated to grow from 6 to 9 billion by
2030.It will obviously be higher by 2054