From: everything-list@googlegroups.com
[mailto:everything-list@googlegroups.com] On Behalf Of meekerdb
Sent: Thursday, March 06, 2014 9:39 PM
To: everything-list@googlegroups.com
Subject: Re: The situation at Fukushima appears to be deteriorating
On 3/6/2014 10:40 AM, John Clark wrote:
On Wed, Mar 5, 2014 at 4:22 PM, <ghib...@gmail.com> wrote:
> you said somewhere you weren't bothered about the 0.8C rise to date
That's right, the Human race has never been more numerous, longer lived,
better educated or richer than it is today so global warming seems to have
caused little harm and may even have been helpful. That shouldn't be a big
surprise, after all we don't know what the perfect temperature to maximize
human happiness is, but I doubt it's exactly .8C less than it is right now.
> I didn't catch whether you are concerned about the projections by 2100?
No I am not at all concerned by the 2100 projections, I say this for 5
reasons:
1) I have little confidence in long term climate models. Anybody reading
them would think CO2 is the most important greenhouse gas, but it isn't,
water vapor is.
CO2 is more important because it accumulates in the atmosphere. Water vapor
has more effect as an amplifying feedback because it stays roughly in
equilibrium with ocean surface temperature.
And they can't answer one important question, if the world's temperature
increases will that create more clouds or fewer clouds? It's a very simple
question with profound consequences because clouds regulate the amount of
solar energy that runs the entire climate show. Increased temperature means
more water evaporates from the sea, but it also means the atmosphere can
hold more water before it is forced to form clouds. So who wins this tug of
war? Nobody knows, its too complicated. Water vapor is a far more powerful
greenhouse gas than CO2 and unlike CO2 it undergoes phase changes at earthly
temperatures, it can be a solid a liquid or a gas which makes it
astronomically more complicated than CO2 which is always just a gas, at
least on this planet.
Perhaps you are unaware that recent work has made headway in answering
precisely that cloud cover question. I cite the abstract of the study
published in Nature. It comes to conclusions you probably do not want to
hear, so I am confident you will find some way of doing so.
Spread in model climate sensitivity traced to atmospheric convective mixing
<http://www.nature.com/nature/journal/v505/n7481/full/nature12829.html>
Steven C. Sherwood,
Sandrine Bony
& Jean-Louis Dufresne
Equilibrium climate sensitivity refers to the ultimate change in global mean
temperature in response to a change in external forcing. Despite decades of
research attempting to narrow uncertainties, equilibrium climate sensitivity
estimates from climate models still span roughly 1.5 to 5 degrees Celsius
for a doubling of atmospheric carbon dioxide concentration, precluding
accurate projections of future climate. The spread arises largely from
differences in the feedback from low clouds, for reasons not yet understood.
Here we show that differences in the simulated strength of convective mixing
between the lower and middle tropical troposphere explain about half of the
variance in climate sensitivity estimated by 43 climate models. The apparent
mechanism is that such mixing dehydrates the low-cloud layer at a rate that
increases as the climate warms, and this rate of increase depends on the
initial mixing strength, linking the mixing to cloud feedback. The mixing
inferred from observations appears to be sufficiently strong to imply a
climate sensitivity of more than 3 degrees for a doubling of carbon dioxide.
This is significantly higher than the currently accepted lower bound of 1.5
degrees, thereby constraining model projections towards relatively severe
future warming.
Chris
It's complicated, but not beyond study and empirical studies indicate clouds
tend to increase warming: http://www.sciencemag.org/content/330/6010/1523
A Determination of the Cloud Feedback from Climate Variations over the Past
Decade
A. E. Dessler
Estimates of Earth's climate sensitivity are uncertain, largely because of
uncertainty in the long-term cloud feedback. I estimated the magnitude of
the cloud feedback in response to short-term climate variations by analyzing
the top-of-atmosphere radiation budget from March 2000 to February 2010.
Over this period, the short-term cloud feedback had a magnitude of 0.54 ±
0.74 (2σ) watts per square meter per kelvin, meaning that it is likely
positive. A small negative feedback is possible, but one large enough to
cancel the climate's positive feedbacks is not supported by these
observations. Both long- and short-wave components of short-term cloud
feedback are also likely positive. Calculations of short-term cloud feedback
in climate models yield a similar feedback. I find no correlation in the
models between the short- and long-term cloud feedbacks.
There's no plausible theory by which clouds could nullify the warming caused
by increased CO2 and uncertainty goes both ways.
And then there is the important issue of global dimming, the world may be
getting warmer but it is also getting dimmer. For reasons that are not
clearly understood but may be related to clouds, during the day at any given
temperature it takes longer now for water to evaporate than it did 50 years
ago; climate models can't explain why it exists today much less know if the
effect will be larger or smaller in 2100.
Sure they can. It's due to increased aerosols and increased clouds. The
IPCC AR4 models predict the increased cloudiness. The uncertainty about
cloud effects arises because low clouds and high clouds have different
effects and the height of clouds is harder to predict.
2) Even if the climate models are correct it is not at all clear if on the
global scale the increase in temperature would be a good thing or a bad
thing; however I do know that far more people freeze to death than die of
heatstroke.
It's plenty clear that 4degC would not be a good thing. A lot more people
die from starvation than freezing.
3) Even if it's a bad thing, as of 2014 no environmentalist has proposed a
cure for global warming that wasn't far worse than the disease, although
some non-environmentalists may have.
There are plenty of good proposals from environmentalist.
http://www.amyhremleyfoundation.org/php/education/impacts/NaturalCycles/Poss
ibleRemedies.php
http://www.greenbang.com/global-warming-cure-for-global-warming_7007.html
4) Even if it is a bad thing there are plenty of worse problems that will
hit before 2100 to worry about.
2100 is just when it get so bad people will wonder why the hell we didn't do
anything about earlier.
Most science stories are under reported in the mainstream press, but global
warming is almost as over reported as ancient astronauts or stories about
Nostradamus.
5) In 2100 if we find that global warming is causing us serious trouble we
can deal with it then when out toolbox for fixing things will be vastly
larger than it is now.
Yeah, we'll just fire up our tokomaks, cold fusion, and LFTRs and pump all
that CO2 down the fracking wells, neutralize the ocean acidity and spray
sulfur into the stratosphere. What could be easier.
Brent
Brent
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