The Truth About Geoengineering

The Truth About Geoengineering

The Truth About Geoengineering

Global warming is
accelerating, and although engineering the climate strikes most people
as a bad idea, it is time to take it seriously.



Officials
prepare to seed clouds near Bangkok, 2007. Royal Thai Air Force
rainmakers hoped to coax rains to clear away thick smoke from forest
fires and stubble burning. (Sukree Sukplang /Courtesy Reuters)

The failure to make much progress at the UN Climate Change Conference
in Doha, Qatar this winter was yet another reminder that the world
might soon face extreme climate shifts. In response, it is becoming
increasingly likely that governments will adopt risky strategies, known
as “geoengineering,” to rapidly cool the planet. Four years ago, in
order to raise awareness about geoengineering, we published “The Geoengineering Option” in Foreign Affairs.

Almost nobody thought that such tactics -- which included spraying
particles into the upper atmosphere to make the earth more reflective,
akin to how big volcanoes cool the planet -- were a particularly good
option. The risks were simply too great and the unknowns too many.
Still, if reliable data and specific models showed that climate change
was about to get out of hand, we wrote, such drastic measures might
start to look more appealing. The world could no longer ignore the
geoengineering option, and we argued that a major science program should
begin to explore it.

These days, barely a month goes by without new research that shows
that the planet’s climate could be more sensitive to global warming than
experts previously thought. For example, some ice sheets now appear a
lot less stable than scientists had imagined. And new estimates of how
much the sea will rise when ice sheets melt far surpass the best
estimates of just a few years ago. It is clear that, unchecked, climate
change won’t just menace natural ecosystems; it will also cause severe
harm to humans and could even threaten national security. And, because
governments have made barely any progress in controlling the emissions
that cause global warming -- the 2000s saw the most rapid growth in
emissions of carbon dioxide and other warming gases since the 1970s --
it’s not so crazy to imagine that some nation will launch an emergency
geoengineering scheme, perhaps before its viability and consequences are
understood.

Since we wrote our essay, press coverage of geoengineering has
exploded. The topic makes for good copy: it is weird, sexy, and steeped
in exotic science. The term is also incredibly vague, including both
techniques for removing carbon dioxide from the air and technology that
could rapidly change the amount of sunlight reflected back to space and
cool the planet. That method is often termed solar radiation management
(SRM).

Carbon dioxide removal schemes include everything from planting trees
to fertilizing the oceans in an attempt to cajole great blooms of phytoplankton.
Both hinge on photosynthesis, which sucks carbon dioxide from the air;
carbon dioxide is the chief long-term cause of global warming. These
techniques also include installing scrubbers almost anywhere on the
planet, which can strip carbon dioxide out of the atmosphere. Such
removal strategies are intriguing, but seem likely to cost hundreds of
billions of dollars a year and would take decades to have much of an
effect.

In contrast, SRM technologies could cool the planet in just a few
months by tinkering with the planet’s energy balance. The usual
proposals involve spraying material into the stratosphere, where it
would turn into reflective clouds, or blowing seawater into the air,
with a similar effect. The clouds could deflect just enough incoming
sunlight to offset, crudely, the number of degrees human emissions have
warmed the planet. Flying a fleet of high-altitude aircraft that spray
particles into the upper atmosphere would cost perhaps ten billion
dollars per year -- a pittance for a country that is suffering from
severe climate change and seeks a quick solution.

Most carbon dioxide removal schemes appear relatively safe, although
tinkering with a fragile ecosystem by fertilizing the ocean does involve
risks. In contrast, SRM raises serious political and policy questions.
Although quick and cheap, messing with the complex and imperfectly
understood climate system, which is already stressed by warming gases,
could end badly. Severe side effects might, for example, include a shift
in the seasonal monsoons that many countries rely on for rainfall and
agriculture, or accelerate the destruction of the ozone layer. No one
knows whether it would be possible to predict and offset all such
harmful side effects or how much it might cost. Further, once an SRM
system is deployed for an extended period of time, stopping it suddenly
would lead to even more rapid and severe climate change as the mask is
lifted. Another wrinkle is that some aspects of climate change, such as
degraded coral reefs, might be irreversible, and, since the driving
forces behind the destruction would remain, it would be particularly
irresponsible to deploy SRM without an accompanying program to control
carbon emissions.

Given the real and imagined dangers, a movement to regulate
geoengineering has been gaining momentum. In the fall of 2010, 193
governments adopted a nonbinding decision under the United Nations
Convention on Biological Diversity that would all but ban testing of
geoengineering systems. Most environmental NGOs seem to be opposed to
even talking about geoengineering out of fear that it might distract
from the urgent task of controlling emissions or encourage governments
to go ahead with their own projects.


Source:-
http://www.foreignaffairs.com/articles/139084/david-g-victor-m-granger-morgan-jay-apt-john-steinbruner-kathari/the-truth-about-geoengineering