This study from Yale University seems contradictory to what we know about aerosols. Generally more aerosols like SO2 cool the climate, but in this case they are saying “it’s offset by the cooling effect of nitrate that forms from nitrogen oxides in jet exhaust.” Interesting.
Removing sulfur from jet fuel cools climate
A Yale study examining the impact of aviation on climate change found that removing sulfur from jet fuel cools the atmosphere. The study was published in the October 22 issue of Geophysical Research Letters.
“Aviation is really important to the global economy. We better understand what it’s doing to climate because it’s the fastest growing fossil fuel-burning sector and there is no alternative to air travel in many circumstances. Emissions are projected to increase substantially in the next two decades—by a factor of two—whereas projections for other sectors are expected to decrease,” said Nadine Unger, the study’s author and assistant professor of climate science at the Yale School of Forestry & Environmental Studies.
Particles of sulfate, formed by burning sulfur-laden jet fuel, act like tiny mirrors that scatter solar radiation back into space. When sulfur is removed from the fuel, warming occurs but it’s offset by the cooling effect of nitrate that forms from nitrogen oxides in jet exhaust. The result is that desulfurization of jet fuel has a small, net cooling effect.
In 2006 the United States introduced an ultralow sulfur standard for highway diesel, and the Federal Aviation Administration (FAA) is interested in desulfurized jet fuel for its potential to improve air quality around airports. Aircraft exhaust particles lodge in the lungs and cause respiratory and cardiovascular illness. In 2006 there were more than 31 million flights across the globe, according to an FAA emissions inventory.
“It’s a win-win situation, because the sulfate can be taken out of the fuel to improve air quality around airports and, at the same time, it’s not going to have a detrimental impact on global warming,” she said.
Unger used a global-scale model that assessed the impact of reducing the amount of sulfur in jet fuel from 600 milligrams per kilogram of fuel to 15 milligrams per kilogram, which is the level targeted by the U.S. Department of Transportation.
The study also simulated the full impacts of aviation emissions, such as ozone, methane, carbon dioxide, sulfate and contrails—those ribbons of clouds that appear in the wake of a jet—whereas previous studies examined each chemical effect only in isolation.
“In this study we tried to put everything together so that we account for interactions between those different chemical effects,” said Unger. “We find that only a third of the climate impact from aviation can be attributed to carbon dioxide.”
Unger also ran a simulation of aviation emissions at the Earth’s surface and found that the climate impact is four times greater because the emissions occur at altitude in the upper atmosphere.
“The chemical production of ozone is greater in the upper troposphere and its radiative efficiency is greater,” she said. “It’s a stronger greenhouse gas when it’s higher up in the troposphere, which is exactly where aviation is making it.”
The paper, “Global Climate Impact of Civil Aviation for Standard and Desulferized Jet Fuel,” can be found at http://www.agu.org/journals/gl/gl1120/2011GL049289/.
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Latitude asks December 14, 2011 at 9:18 am
How in this world did so many people get fooled into thinking it’s too hot..
~
http://www.cdphe.state.co.us/pp/copan/obesity/obesity.html
In almost any given situation, overweight people are more likely to feel warm than thin folks, simply because the chubby persons are carrying around excess insulation in the form of their body fat. In the summer, many if not most public buildings are air-conditioned to a degree I find uncomfortably cool after a short while, being a skinny guy.
It is easier to sell the idea of Global Warming to obese people. There are increasing numbers of these overweight and severely overweight people, especially in the USA.
I’ve seen it all now. Alan Grayson’s mug staring at me from the home page of WUWT. I wonder if RC has their Monckton picture up yet.
UGH!
polistra says:
December 14, 2011 at 9:27 am
I assume some major corporation has a sulfur-removal product waiting “in the wings”, so to speak.
Actually, it’s removed at the refinery via the hydrotreater. Since the ones doing this study are probably not versed in refinery operations, I’m going to go out on a limb and assume that they have not factored in that there will be additional CO2 emissions due to the desulferization process. The hydrotreater requires Hydrogen to desulfurize the fuel, which will need to be produced. This will require either the combustion of some of the oil being refined into fuel or natural gas. Either way, further reducing sulfur in jet fuel will necessitate increased CO2 emissions. At best there will be one additional CO2 molecule added per 2 molecules of SO2 reduced. With the actual probably being somewhere between 1:1 and 1:2 CO2 to SO2.
I worked for a short period of time in a lab that was planning on testing diesel fuel with reduced sulphur. It seems you put the fuel in a pan a place a weighted ball on it, and move it back and forth to determine “lubricity”. If you remove too much sulphur, the fuel no longer has any lubrication properties of its own, and can damage engines. If the diesel industry was worried about trucks, I can imagine the damage in airplane engines. Maybe someone knows if my information above is correct.
But, but, but we’re running out of oil right?
Someone tell the airlines. Someone tell the manufacturers. With a 7 year waiting list just for the Boeing 737 someone needs to do… something.
Same with boat-building – especially oil tankers. What are they for????
Steve P says:
December 14, 2011 at 10:16 am
It is easier to sell the idea of Global Warming to obese people. There are increasing numbers of these overweight and severely overweight people, especially in the USA.
___________________________
Obesity and Global Warming… there’s a correlation in there somewhere.
Most refining technology is owned by major oil companies themselves, but there are some companies, like UOP, who do that for a living. However, this technology is older than the hills, and the patents are probably run out by now. All they have left to make any money on is catalyst sales.
Scratch one conspiracy theory.
PowerofX, how many climate models have been right?
10 days to christmas and I have the heater on full blast NO I am not in the UK I am in sydney my vegy patch has stopped growing bring on global warming
[snip. Chemtrail discussions verboten. ~dbs, mod.]
The AGW meme seems to follow a push to do anything possible to increase the price of energy thereby decreasing demand. The EPA will do anything it can to increase it’s influence over energy producers.
This looks like a good way to do both.
““It’s a win-win situation, because the sulfate can be taken out of the fuel to improve air quality around airports and, at the same time, it’s not going to have a detrimental impact on global warming,” she said.”
I think she means:
“It’s a win-win situation, because the sulfate can be taken out of the fuel generating additional income for the oil company in the process from higher fuel price AND they can then add the sulfur to the fertilizers they make generating income on that side of the process as well from higher fertilizer prices”.
This is exactly why you see oil companies jumping on the global warming bandwagon, because there is a HUGE amount of money to be made for them.
OT, but worthwhile:
I don’t know the original source, but it should be easy to find from details in the article
“Studies” like this make me sad. It seems these people believed that since:
1. A warming atmosphere is bad.
2. Fuel should have all Sulfur removed.
Therefore:
3. Removing Sulfur cools the atmosphere.
See? It’s easy.
1) How many jetliners needed before we can dispense with Haber-Bosch fertilizer?
2) Why do people refer to nitrates, when there is only one nitrate moiety?
If this study happens to be true, and I make no assumptions on that, doesn’t it mean that aircraft are currently net climate warming agents? If that’s true, presumably they would make more difference near airports, correct? And that means that temperatures around airports would be elevated compared to the rest of the world. Which adds yet another problem to the whole measuring temperatures mainly at airports thing.
Based solely on the PR, it would seem that desulferizing jet fuel would have a fairly large cost/benefit ratio, in terms of improving the climate. I can think of a number of other proposals that have much positive financial and climate results.
For instance, a rule that from this point forward all confabs by the IPCC, other government environmental bureaucrats, environmental NGOs, climate science academics, alternative energy vendors, politcians, etc. are required to be done via “teleconferencing”.
For private aircraft, if anyone on the passenger manifest has issued any public statements suggesting that people with far fewer resources than themselves need to modify their lifestyles to their own detriment in order to “save the planet”, the fuel for the flight will be slapped with a 1000% surcharge.
The water trails they leave behind has a much greater cooling effect than any trace component they could remove or add to jet fuel. Remove the artificial clouds that a jet engine makes and you will have a net warming.
I hate it when I get up on a nice sunny day to see it becoming overcast quickly by noon by jet trails. They ruin my daily dose of vitamin D.
Friends:
Two years ago on August 17 2009 I provided a guest post on WUWT titled “Stopping Climate Change”. It can be read at
http://wattsupwiththat.com/2009/08/17/stopping-climate-change/
My article argued that politicians needed an excuse to stop their attempts at geoengineering the climate by harmful measures intended to limit carbon dioxide emissions. And it suggested;
“There are several ways to increase cloud cover, for example small amounts of sulphates, dust, salt or water released from scheduled aircraft would trigger additional cloud formation.”
It went on to say;
“Each of these options would be very much cheaper than constraining the emissions by 20 per cent for a single year. So, any delay to implementation of emission constraints by use of these options would save a lot of money.”
And
“Global temperature has not again reached the high it did in 1998 and has been stable since. But it could start to rise again. If it does then use of one or more of these options could be adopted when global temperature nears 2 degrees Celsius higher than it was at the start of the last century. This would be a cheap and effective counter measure while the needed emission constraints are imposed. Indeed, it would be much cheaper than the emission constraints. It could be started and stopped rapidly, and its effect would be instantaneous (as sunbathers have noticed when a cloud passes in front of the Sun).
Until then there would be no need for expensive ‘seen to be doing something’ actions such as capturing and storing carbon dioxide. Energy and financial policies would not need to be distorted, and developing countries could be allowed to develop unhindered.
Importantly it said;
“Indeed, there would be no need to deploy the counter measures unless and until global temperature rises to near the trigger of 2 degrees C rise.”
The paper reported above adopts the same idea of cloud modification b y sulphur emissions from aircraft except that it considers the effect of altering sulphur emissions from aircraft in the stratosphere instead of in the troposphere.
So, my question is
WHY DOES IT TAKE CLIMATE SCIENTISTS MORE THAN TWO YEARS TO PLAGIARISE FROM WUWT AND THEN TO NOT REFERENCE WUWT IN THEIR PUBLICATION?
Richard
soylent green:
somebody made a mistake.
the navy intends to buy about 450,000 gal of the great grand purple french fry squeezings and pay $12m for it. that comes out to $26…. and change per gallon. not $15.
even worse news is that the ff squeezings have only 95% of the heat value as the regular navy fuel.
c
Removing sulfur from jet fuel cools climate
This seems to fly in the face of the Chinese coal plants, which release sulfur dioxide, are “cooling the planet as CO2 rises” meme.
Jay Davis says:
December 14, 2011 at 11:01 am
PowerofX, how many climate models have been right?
PowerofX I draw your attention to the question posed by Jay Davies. I would like to ask the same question. But in a different form.
Climate Models have been used to scare people witless over sea level rise, extinctions, famine, drought, pestilence…etc. So my question is:
How many Climate models have been 100% correct? If the answer you give is less than 100% please point me in the direction of ANY press release which identifies the error and explains to people we should not be worried about the previous press release.
I ask you Mr/Ms PowerofX because you come to WUWT as an expert, ie, alway telling people they are incorrect.
Over to you Mr/Ms PowerofX
I don’t doubt it the numbers are worse than we thought!
I’m disgusted that our military is being used as a test bed for the Green Agenda. National security is not being advanced by that project. Instead, the Defense Department is being misused, allowing the true cost of these boondoggle programs to be hidden in the Defense budget.
email 0552.txt:
> > > That there is a large potential for a cooling
> > influence is sort of evident in the IPCC figure about the present
> > sulfate distribution–most is right over China, for example,
> > suggesting that the emissions are near the surface–something also
> > that is, so to speak, ‘clear’ from the very poor visibility and air
> > quality in China and India. So, the quick, fast, cheap fix is to put
> > the SO2 out through tall stacks. The cooling potential also seems
> > quite large as the plume would go out over the ocean with its low
> > albedo–and right where a lot of water vapor is evaporated, so maybe
> > one pulls down the water vapor feedback a little and this amplifies
> > the sulfate cooling influence.
[snip]