[ExI] A Nobel laureate and climate change
dennislmay at yahoo.com
Thu Sep 15 18:34:10 UTC 2011
Science Daily News recently reported that 1/4 of the 3 mm rise per
year in the ocean levels is from water being pumped out of
the ground faster than it is returning. Most of this is irrigation -
again supporting Spike's point of view that water is a larger
effect [still poorly modeled] than CO2. It has always been known
that water vapor is the number one green house gas - but not
politically attractive as a target.
From: spike <spike66 at att.net>
To: 'Dennis May' <dennislmay at yahoo.com>; 'ExI chat list' <extropy-chat at lists.extropy.org>
Sent: Thursday, September 15, 2011 1:21 PM
Subject: RE: [ExI] A Nobel laureate and climate change
>>…I find encouraging the way climate science seems to be heading. This comment is from the APS site:
“…The second sentence is a definition that should explicitly include water vapor…”
From:extropy-chat-bounces at lists.extropy.org [mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of Dennis May
>…His data was still better than much of what was collected in heat island
cities or when the actual collection spots representing thousands of square
miles have been moved. Never mind those located next to roof AC units,
black tar roofs, exhaust vents, and any number of problem spots…Dennis
Ja thanks Dennis. Focusing on the central point is this: we hear so much about data collection spots this and heat island that and carbon dioxide production the other, but really, it is easy to do single digit precision BOTECs and see that increased atmospheric CO2 under-accounts for the observed temperature increase.
On the other hand, consider this: temperature data collection sites will always be reasonably close to a road. They don’t take helicopters into some remote site to read, and until recently they didn’t transmit readings via radio signal from remote sites. Now consider that every major agricultural establishment, including illegal marijuana farms, will also be near a road: they need to haul machines in and the crops out of there somehow. Many if not most farms are irrigated. We know that makes a measurable humidity difference downwind of the farms.
This can be sometimes observed firsthand for those of you who fly across landmasses during the day. Find out wind directions, see if you see increased cloudiness downwind of major irrigation systems such as the Midwest wheat and corn fields which use center pivots.
We know that clouds trap heat down, much more effectively than CO2 per unit mass. If major irrigation projects are near roads and temperature data collection sites are near roads, and the term “near roads” represents a surprisingly small fraction of the land surface even in a populated nation, I can easily imagine how the one can impact the other. Get on Google Maps under satellite view and see for yourself.
One further point and I will let it go: I am not a farmer, but I am playing one in real life (long story.) When I am out operating the tractor, I am burning about two to four gallons of Diesel fuel per hour. My irrigation system is licensed to pump and hurl into the air 510 gallons per minute. Of that, I would conservatively estimate that 2 to 5 percent stays in the air, since irrigation is done in the hot, dry summer months, so that’s 10 to 25 gallons per minute or about 600 to perhaps a couple thousand gallons of water going into and staying in the air, so 2 to 8 tons per hour of water going into the air, while my tractor spews typically 20 to 50 kg of Diesel combustion products (about a third of which is water by mass btw), so a factor of about 100 in favor of water vapor during the relatively short time I am actually operating the tractor. But the irrigation system drones on and on, sometimes around the clock for weeks at a time. Even if
we ignore the fact that agriculture at least temporarily pulls CO2 out of the air, a typical ag operation would put more water into the atmosphere than it does CO2, by a factor of many thousands.
Even that ignores the amount of water the crops themselves return to the air through respiration. That 2 to 5 percent notion likely vaaaastly underestimates how much water my irrigation system puts into the atmosphere. Counter-suggestions welcome. Irrigation amounts are measured typically in acre-feet. 20 gallons of Diesel per acre comes out to on the order of a ten acre-microns. (Check my math, did it all in my head, so as not to waste a perfectly good back of an envelope and expensive ink. Hey, thrift is a farmer thing.)
For those of you who stay always in the city, we tend to think of our own activities, driving around to work and back for instance. But compare the amount of fuel you burn in your Detroit with the amount of water you hurl onto your lawn, and do the BOTECs yourself, get your water bill from last month, estimate, do the math, doooo it, you can do it.
There is good news in all this. If global warming is dominated by water vapor, that merely shifts the temperature and humidity equilibrium, rather than introducing risk of runaway greenhouse effect. If we predict that irrigation will result in a warmer wetter planet, most human inhabitants of this cold dry planet will say: HEY COOL! Where do I sign up for that?
After all, we are all Africans, much of which is relatively warm and wet compared to where we settled.
I am guessing what comes out of the next decade of climate science is the realization that the *human contribution* to global warming is waaay dominated by irrigation rather than CO2.
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