Jim Hansen presentation to National Press Club
Jim Hansen is head of the US NASA Goddard Institute's climate research. Of course, given the efforts of the Bush administration to silence him, I presume in this article that he is speaking as a private citizen, its a good (and reasonably brief) summary of current thinking.
(via Greenleap)
Charts used for presentation at the National Press Club yesterday
are at: http://www.columbia.edu/~jeh1/dots_feb2007.ppt
The main points are:
A. Climate Sensitivity: What can be called the "Charney" or "fast
feedback" climate sensitivity is now well-established: it is
approximately 3C for doubled CO2 (forcing of 4 W/m2). However,
some of the "boundary forcings" in this "Charney" definition are
themselves variables or slow feedbacks. Indeed, the boundary
forcings (surface albedo and long-lived GHGs) that are the principal
mechanisms for climate change on the 100 ky time scales are in fact
feedbacks on those time scales. The problem for humanity is that
some of these "slow" feedbacks are not so slow - they may
experience significant change this century and increase the climate
response beyond that which is calculated by the typical model used
in IPCC simulations. [Vegetation feedback - forests and shrubs are
moving poleward, into regions that were tundra.Ice sheets are
getting darker (wet) and before the century is out they could get
smaller. Long-lived GHGs may provide a positive feedback, as in
paleo experience, e.g., from methane hydrates.] So the effective
climate sensitivity on the century and longer time scales is greater
than the Charney sensitivity. We will begin to notice these additional
feedbacks now, as we have entered the period of significant almost-
monotonic global warming with isotherms moving poleward.
B. Dangerous Level. We do not know what long-term level of CO2
constitutes "dangerous human-made interference" (the level can be
raised somewhat if we reduce other GHGs such as CH4), but it has
become clear that it is not greater than about 450 ppm, and may be
considerably lower. Given the fact that at least ~ one-quarter of
fossil fuel CO2 emissions remains in the air "forever" (more than 500
years), and given the magnitude of the oil, gas, coal and
unconventional fossil fuel reservoirs, it is follows that readily
available oil and gas are going to take atmospheric CO2 to at least
~450 ppm. Thus even with responsible efforts to slow emissions, it
is likely that atmospheric CO2 amounts will exceed the dangerous
level, and we will need to find ways counteract the warming effect of
these GHGs.
C. Responsibility. Despite the fact that China will soon exceed the
U.S. in current CO2 emissions, the U.S. will continue to be primarily
responsible for the human-caused climate change for many decades
into the future. So, unless we begin to act responsibly, we will leave
a tremendous moral burden, and perhaps a legal burden, for our
children and grandchildren (and ourselves: some effects are going to
be obvious soon enough).There is still time to keep GHGs at
approximately or reasonably close to the "dangerous" boundary, but
only if we get on a fundamentally different energy track within a
decade, which requires that we begin to move "now". If we do not
stay within or close to that boundary, actions to avert irreversible
effects (species extinctions, ice sheet disintegration/sea level rise)
are not likely to be effective.
D. Geoengineering. I doubt the feasibility/desirability of geo-
engineering suggestions such as the human volcano or space
mirrors. If it proves necessary to counteract past emissions, why not
a more "natural" method of drawing CO2 out of the atmosphere:
negative-CO2 power plants that burn biofuels (derived, e.g., from
cellulostic plants)? I like this partly because it has red states coming
to the rescue of (mostly coastal) blue states*, and it will be a boon to
red states and farmers. CO2 can be fail-safe sequestered under
ocean sediments, where it is stable, in effect putting it back where it
came from. *By the way, there are white states - I live in one
(Pennsylvania) and grew up in one (Iowa), (others: Minnesota,
Wisconsin...) - our vote counts.
E. Other Recommendations.
(1) Moratorium on building coal-fired power plants until they include
sequestration. The public needs to enforce this temporarily until the
people we elect are able to do the job.Excessive worry about power
plants in other countries is unwarranted: these countries will soon
begin to be realize that all old-technology coal-fired power plants
eventually must be bulldozed.
(2) There must be a gradually rising price on carbon emissions and it
must be complemented by increased technology investment, so that
consumers have choices that allow them to reduce their carbon
needs. Continued rise in the carbon tax must be certain, so
businesses will invest and spur innovation. Positive long-term
impacts on the economy, balance of payments, energy
independence, national security... Presently the government
provides only chicken feed for technology development, except for
coal and nuclear power. I hope that government leaders who stand
in front of renewable energy facilities, trying to claim credit, do not
fool the public.
(3) Incentives (carbon price) have to be complemented with energy
efficiency standards. There is enough potential in efficiency to take
care of increased energy needs over the next decade and more, if
the government gets behind efficiency standards.Instead our
government is idiotically standing in court with those who resist
standards for the sake of short-term profits.(Does this have anything
to do with special interests and recommendation #5 below?).
Structural barriers that inhibit efficiency (e.g., regulations that result
in power companies making more money if they sell more electricity,
rather then if they help reduce requirements) need to be addressed.
(4) Congress should ask the National Academy of Sciences to do a
prompt study on the stability of ice sheets. This topic is, I believe,
the prime driver of what constitutes a "dangerous" GHG level. The
matter is too urgent to wait for the necessarily slow IPCC process. A
study of this sort avoids the pressures for "scientific reticence" that
can affect individuals. The Academy was established by Abraham
Lincoln for purposes such as this.
(5) Public Affairs offices at the science agency headquarters should
be staffed by non-political professionals. A democracy is based on
the premise that the public is informed, honestly informed. What
would our Founding Fathers think of the Offices of Propaganda that
our executive branch has installed in these agencies? Is the public
even aware that when a government scientist testifies to Congress
his testimony must be approved and edited by the White House?
Where does the authority for this come from? Is Congress ceding
authority to a unitary executive? Is this the way our democracy was
intended to work?
The greatest obstacle to solving the climate crisis is the "special
interests". As long as the coffers of our elected representatives can
be filled by special interests, the latter will keep calling the tunes.
Until there is true campaign finance reform, the special interests will
continue to make a mockery of the central proposition of our
democracy, that the commonest of men should have a vote equal in
weight to that of the richest, most powerful citizen.
Finally, you might look into the activity at www.stepitup07.org
organized by Bill McKibben. In coordination with Earth Day Network,
they are planning nationwide rallies on April 14.
Jim
Posted by admin at March 1, 2007 7:53 PM
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