Geoscience Reference
In-Depth Information
THE CHALLENGE OF A LOW-CARBON ECONOMY
The chances are slim that technology can do the job without gov-
ernment policies mainly because the required changes are so large.
Take as an example the U.S. policy set by the Obama administration.
Using 2005 levels as a baseline, the proposal was to reduce CO
2
and
other greenhouse-gas emissions 17 percent by 2020 and by 83 percent
by 2050. The general outline of this policy was endorsed by several ad-
visory groups.
Meeting these targets with domestic reductions alone would re-
quire major changes in the behavior of the U.S. economy. We can show
this using the past and projected “carbon intensity” of economic activ-
ity. This concept measures the ratio of CO
2
emissions to output.
Figure 37 shows on the left the historical trend of decarbonization
about 2 percent per year. Beyond 2010 there is a line labeled “U.S. pol-
icy proposal.” This shows the required rate of decarbonization over the
coming four decades under the policy proposed by the Obama adminis-
tration and several scientifi c advisory groups. Over the entire 2010-
2050 period, the United States would need to decarbonize at 6 percent
Outside of electronics, no sector has achieved long-term rates of pro-
ductivity growth at that pace for extended periods of time.
We can perform the same calculation for the world as a whole. To
achieve the 2°C target at a global level, the global rate of decarboniza-
This is less ambitious than the U.S. objective because the United States
is proposing steeper reductions for rich countries than for developing
countries. However, at the global level, it is still an enormous challenge.
To summarize: Achieving the emissions reductions contemplated by
U.S. policy and consistent with the Copenhagen 2°C temperature target
would require more rapid technological shifts than have been seen in
almost any industry. This technological fact underlines the daunting
challenge posed by climate change.
