How Might We Cool The Earth?

• Author: Craig M. Pease
• Position: Ph.D., a research scientist, teaches at the Vermont Law School Environmental Law Center
• Pages: 20-20

Page 20 ❧ THE ENVIRONMENTAL FORUM Copyright © 2009, Environmental Law Institute®, Washington, D.C. www.eli.org.

Reprinted by permission from The Environmental Forum®, March/April 2009

By Craig M. Pease

How Might We

Cool The Earth?

Scientif‌ic knowledge about global

climate change has now reached

the point where there is longer any

real debate over its fact or cause. is

in turn has engendered an important

yet under-appreciated shift in the fo-

cus of the technical literature, from

studying the problem to f‌inding a

solution. We have moved from the

realm of science to the practice of en-

gineering.

Before discussing possible future

solutions, it is sensible to summarize

our “progress” to date. Since the 1997

Kyoto Protocol, atmospheric carbon

dioxide has risen from 363 to 386

parts per million. Even more worri-

some is the evidence that this increase

is accelerating, driven principally by

global economic growth, as summa-

rized in two companion articles by Jo-

sep Canadell, Michael Raupach, and

colleagues in the Proceedings of the Na-

tional Academy of Sciences. Moreover,

in a recent and not uncontroversial

paper in e Open Atmospheric Science

Journal, James Hansen and colleagues

suggest a goal of 350 ppm or lower to

prevent catastrophic loss of the Green-

land and Antarctic ice sheets, a target

well below the consensus view of even

several years ago. Everything is mov-

ing, in the wrong direction.

Science is the study of the possible

and probable, whereas engineering is

the art of the practical. Science tells

us loss of the polar ice sheets is pos-

sible, though there remains debate as

to exactly what atmospheric carbon

dioxide level will make this probable.

It is the engineers who must actu-

ally supply a cost-ef‌fective solution.

is brings us to Daniel Sarewitz and

Richard Nelson’s December 2008

commentary in Nature. e article

posits “three rules for technological

f‌ixes,” the apparent premise of which

will no doubt dismay many of my

readers.

eir contribution deserves a fair

hearing. It is important not for its pro-

vocative and surprising bottom-line

conclusion (about which more later),

but rather for its path to that endpoint.

ey ask us to contemplate a broad ar-

ray of potential engineering technolo-

gies for reducing atmospheric carbon

dioxide, and to develop explicit rules

to cull out the scientif‌ically workable

from the politically, legally, socially, or

economically dead on arrival.

Space limitations preclude a full

presentation of their rules here. One

can, however, illustrate the essence

of their argument by

comparing the policy

options available to

reduce carbon diox-

ide emissions from

coal-f‌ired power

plants. As Hansen

has forcefully argued, reducing the

atmospheric carbon dioxide derived

from these emissions is key. Evidently,

our options are to reduce demand for

electricity (increased energy ef‌f‌icien-

cy), replace these plants with energy

from non-carbon sources (biofuels

or nuclear power), or capture carbon

dioxide as the coal is burned (carbon

capture and sequestration).

Many in the environmental com-

munity favor less esoteric engineer-

ing. Fair enough. We do not need a

Manhattan Project to advance the

engineering of blown cellulose insu-

lation. e engineers have this one

f‌igured out. Yet there remain sub-

stantial, perhaps huge, opportunities

to improve the energy ef‌f‌iciency of

residential and commercial buildings.

Here the engineering works, but our

existing political and social institu-

tions cannot capture all the opportu-

nities the engineers have provided.

Biofuels present somewhat dif‌ferent

obstacles. ough you might quibble

over the accounting, a posse of outraged

scientists and engineers argue convinc-

ingly that we burn as much or more

fossil fuel to grow corn than the energy

value of the ethanol. Corn ethanol will

not reduce atmospheric carbon diox-

ide. To understand why the incoming

secretary of agriculture favors it, look at

the electoral map. Obama’s margin of

victory was less than the electoral votes

of the Midwest farm states receiving

substantial corn ethanol subsidies. Here

we can achieve a political compromise,

but only to further a scientif‌ically non-

sensical program.

Sometimes it is a real advance to just

state the obvious. Sarewitz and Nelson,

authors of the Nature commentary, sug-

gest we remove carbon dioxide from the

atmosphere with machines built spe-

cif‌ically for this task. e engineering

dif‌f‌iculty appears roughly equivalent to

capturing and seques-

tering carbon dioxide

from coal-f‌ired power

plants. Yet it looks

politically superior, as

it would not require

the cooperation of the

owners of coal-f‌ired power plants.

eir rules thus push the techni-

cal literature beyond engineering nar-

rowly def‌ined, to provide an explicit

framework for interdisciplinary prob-

lem-solving, just as the IRAC tem-

plate structures legal analysis.

We obviously need interdisciplin-

ary solutions to global climate change.

Yet judging by current atmospheric

carbon dioxide trends, we have yet to

f‌ind a single policy option that is at

once achievable by politicians, sen-

sible to economists, not in violation

of scientif‌ic knowledge, and actually

buildable by engineers.

Craig M. Pease, Ph.D., a research scien-

tist, teaches at the Verm ont Law School En-

vironmental L aw Center. He can be reached

at cpease@ve rmontlaw.edu.

S   L

We have moed om

the realm of science

to the practice of

engineering