[Vision2020] Strategies for a Changing Planet: Awareness

[Art Deco]

From:  *Popular Science*
Strategies for a Changing Planet:
Awareness<http://www.popsci.com/science/article/2012-06/climate-change-here-its-time-get-ready>
  [image: Feature] <http://www.popsci.com/category/category-badges/feature>
  We're on a collision course with extreme weather. It's time to
acknowledge that, and to prepare
 By David Roberts Posted 07.09.2012 at 10:12 am 29
Comments<http://www.popsci.com/science/article/2012-06/climate-change-here-its-time-get-ready?page=#comments>

  Already Happening Nick Jacques

*Climate change is already happening, and it's time to get ready. Here's
how we could adjust our most basic needs--food, water, shelter--to survive.
<http://www.popsci.com/category/tags/climate-preparation>*

There is no longer any question of preventing climate change. Some 98
percent of working climate scientists agree that the atmosphere is already
warming in response to human greenhouse-gas emissions, and the most recent
research suggests that we are on a path toward what were once considered
“worst case” scenarios.

How much warmer must it get before things really go to hell? “Climate
sensitivity” remains a subject of intense investigation, and what counts as
hellish is a matter of judgment, but United Nations climate negotiators
have settled on a goal to limit atmospheric carbon dioxide to 450 parts per
million, which would cause the global mean temperature to peak no more than
3.6°F above preindustrial levels. If it gets much hotter than that, we will
most likely be confronted by levels of drought and severe storms for which
humanity has no precedent. That sounds bad enough—and indeed,
postindustrial temperatures have already risen by as much as 1.6°—but
there’s increasing reason to believe, as James Hansen and many other
climate scientists do, that severe effects will arrive well below 450 ppm,
and possibly below today’s level of 396 ppm. Danger is much closer than we
thought.

We will almost certainly blow past 3.6° in any case. One recent study found
that the average global temperature would rise another 3.2° by the end of
the century even if human carbon emissions dropped to zero tomorrow, a
scenario that is, of course, extremely unlikely. Simply limiting the
temperature rise to twice the “safe” level would require heroic, sustained
global effort, a level of ambition that appears nowhere in evidence. And if
humanity does nothing to restrain climate pollution, the trajectory it’s on
right now could carry the rise to as much as 10° within the century.

We no longer have a choice about whether to confront major
changes<http://www.popsci.com/science/article/2012-02/could-climate-change-make-mount-everest-unclimbable>already
in the works. By the end of this century, sea levels will rise,
drought will spread, and millions of animals, human and otherwise, will be
driven from their homes. Scientists call the process of preparing for these
changes “adaptation,” but a more apt term can be found in the tech world:
ruggedizing. Greater extremes require tougher, more resilient societies.
** * **

In 2009, researchers from the University of Oxford, the Tyndall Center for
Climate Change Research and the U.K. Met Office Hadley Center organized a
conference on what a change of 7.2° or greater might look like—oddly, one
of the first concerted scientific examinations of the impacts of
temperatures that high. Here are some of the results: 7.2°, which could
conceivably arrive as early as 2060, would mean a planet that was hotter
than at any time in the past 10 million years. By 2100, sea levels would
rise by as much as six feet, leaving hundreds of millions of the world’s
coast-dwellers homeless, even as huge swaths of the ocean itself became
“dead zones.” Glaciers and coral reefs would largely vanish from the
planet.

It may be possible to weather this onslaught if we begin preparing now, by
building low-carbon, high-density cities away from the coasts, radically
improving the efficiency of water and energy systems, boosting local and
global emergency-response capacities, and adjusting to a less consumption-
and waste-oriented lifestyle. But although humans are an ingenious species,
some changes simply exceed any realistic capacity for adaptation. The real
threat, the existential threat, is that climate change will gain so much
momentum that humanity loses what remaining power it has to slow or stop
it, even by reducing carbon emissions to zero. If change becomes
self-sustaining, our children and grandchildren will inherit an atmosphere
irreversibly out of control, with inexorably rising temperatures that
could, according to one recent study, render half of Earth’s currently
occupied land uninhabitable—literally too hot to bear—by 2300.

Given the risks humans pose to the planet, we might someday leave Earth
simply to conserve it.These are only scenarios spit out by climate models;
there’s no way to predict exactly what will happen. It might be tempting to
seize on uncertainty as reason to wait and see. Why prepare if we don’t
know exactly what we’re preparing for? But the uncertainties in the science
of climate impacts—and they are legion—make the future more perilous, not
less. Things look bad, and if there’s a chance they could turn out better
than expected, there’s also a chance they could turn out worse. Out on the
“long tail” of the probability curve, there are small but not insignificant
chances for damages that are, for all practical purposes, unlimited. For
instance, if several of the world’s major land-based ice sheets melt, we
could see a 40-foot rise in sea levels within centuries.

These are stark and discomfiting findings. Above all, they suggest that
global temperature should be held as low as is still possible, at virtually
any cost. But they also make clear that some changes are inevitable. We no
longer have a choice between mitigating climate change and adapting to
climate change. We must do both.
** * **

When we talk about adaptation, we often imagine accommodating a specific
new set of conditions; a temperate place gets too hot, a cold place gets
temperate, so we move our farms around and get on with it. But we simply do
not know, and most likely will not for some time, what particular
temperature we are bound for, or whether there will ever again be a stable
temperature. It is not a specific set of conditions but uncertainty itself
to which we must
adapt<http://www.popsci.com/science/article/2012-06/how-urban-planners-will-accommodate-climate-refugees>
.

Even as we remain flexible, we will have to think and work on a very large
scale. Major infrastructure projects—highways, dams, levies, electrical
transmission lines, trains and subways—represent investments meant to pay
off over generations. The New York City subway system is more than 100
years old. Today there’s a nontrivial chance that much of Manhattan will be
under water in 100 years. How do we invest in the future when it has become
so cloudy and threatening? As the stories in this series
report<http://www.popsci.com/category/tags/climate-preparation>,
scientists and engineers already have many excellent (and some less than
excellent) answers. It can be done. But the time to do it is now.

*David Roberts is a senior staff writer for* Grist.org <http://grist.org/>.
*He lives in Seattle.*
  Previous Article: The Battle Over Climate
Science<http://www.popsci.com/science/article/2012-06/battle-over-climate-change>

Next Article: Strategies for a Changing Planet:
Shelter<http://www.popsci.com/science/article/2012-06/how-urban-planners-will-accommodate-climate-refugees>

-- 
Art Deco (Wayne A. Fox)
art.deco.studios at gmail.com
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