Originally posted by luxordelphi
reply to post by Afterthought
Why even have contrails unless they are chemtrails? The technology exists to eliminate them.
Notes on the Subject of Contrails
In 1994 the government awarded a $16 million contract to the Northrop Corporation to fine-tune stealth bombers in a number of ways. One retrofit involved the installation of five “contrail management systems.”
Contrails And The Dark Side
In 2000, Air International magazine published an article about the B-2, and explained how it was that the B-2 didn't produce contrails. "As for elimination of contrails (normally a giveaway, even for a stealth aircraft), the USAF said chlorofluorosulphonic acid was injected into the jets to eliminate contrails."
While the Science paper does not prove that aerosols are behind the recent dimming and brightening trends -- changes in cloud cover have not been ruled out -- another new research result supports that conclusion In a paper published March 8 in the American Geophysical Union's Geophysical Research Letters, a research team led by Anastasia Romanou of Columbia University's Department of Applied Physics and Mathematics, New York, also showed that the apparently opposing forces of global warming and global dimming can occur at the same time.
The combined effect of global dimming and warming may account for why one of the major impacts of a warmer climate -- the spinning up of the water cycle of evaporation, more cloud formation and more rainfall -- has not yet been observed. "Less sunlight reaching the surface counteracts the effect of warmer air temperatures, so evaporation does not change very much," said Gavin Schmidt of GISS, a co-author of the paper. "Increased aerosols probably slowed the expected change in the hydrological cycle."
“One of Glory's two instruments, the Aerosol Polarimetry Sensor, will have the unique ability to measure globally the properties of natural and human-made aerosols to unprecedented levels of accuracy," said Mishchenko, who is project scientist on the mission.
Be logical, and try to learn about the topic before making claims that a few hundred jets and their "exhaust' is a "toxic problem",
whilst ignoring literally millions of cars and trucks and motorcycles and mopeds and lawnmowers (etc), here on the ground!!
No....what you posted were mention of attempts to mitigate CONTRAILS!! Not imaginary "chemtrails"! Contrails......even the "stealth" airplanes, like the B-2, still use jet engines, and the "give-away" and 'tell-tale' that destroys their "stealthiness" are the contrails that they naturally form, when conditions are suitable for contrail formation!! This is so simple to understand!
The environmental impact of aviation occurs because aircraft engines emit noise, particulates, and gases which contribute to climate change and global dimming. Despite emission reductions from automobiles and more fuel-efficient and less polluting turbofan and turboprop engines, the rapid growth of air travel in recent years contributes to an increase in total pollution attributable to aviation. In the European Union, greenhouse gas emissions from aviation increased by 87% between 1990 and 2006.
Like all human activities involving combustion, most forms of aviation release carbon dioxide (CO2) and other greenhouse gases into the Earth's atmosphere, contributing to the acceleration of global warming and (in the case of CO2) ocean acidification. In addition to the CO2 released by most aircraft in flight through the burning of fuels such as Jet-A (turbine aircraft) or Avgas (piston aircraft), the aviation industry also contributes greenhouse gas emissions from ground airport vehicles and those used by passengers and staff to access airports, as well as through emissions generated by the production of energy used in airport buildings, the manufacture of aircraft and the construction of airport infrastructure.
Why? Because they are expensive. Ironically one the the technologies (the injection of acid, tested my the military, but abandoned as impractical due to the corrosive effects) would turn the contrail from a harmless cloud of ice crystals into an actual "chemtrail", albeit an invisible one.
One early approach was the injection of chlorosulfonic acid into the exhaust of an engine to diminish the particle size of water below the visible range. However, this substance is extremely corrosive.
Results indicate that the new contrail prediction algorithm developed by the Tactical Environmental Support Branch provide a dramatic improvement in the ability to forecast contrails. The new algorithm produced accurate contrail forecasts 85 percent of the time compared to 57 percent correct for the Air Force Global Weather Center operational contrail prediction algorithm.
So the answer to "why have contrails unless they are chemtrails?" is that they "have contrails" in order to minimise fuel burn so reduce costs and reduce pollution.
Originally posted by luxordelphi
We can afford to bail out banks and auto manufacturers and pay for installation after installation in Antarctica and put up spy satellite after spy satellite with quantum computers to collate data but we can't have an impact on global dimming caused by persistent contrails because...why?
Originally posted by luxordelphi
I mean about how expensive it supposedly is to change altitude slightly and how polluting it is to fly lower. Just how much more money is it? And how much added pollution is it? And why wouldn't you change altitude to fly a bit higher? Why would it always be lower?
If your statement is based on something actual rather than something assumed, there must be a cost study somewhere. And a pollution by altitude study.
Jet aircraft, however, have a unique form of harming the environment that is associated exclusively with them: contrails. They are the long, thin clouds that are blasted out of the exhaust nozzle of jet engines at high altitudes. Some days they fade away within a few minutes and they pose no threat. It is the days that perfect conditions exist when they do their damage, drifting and expanding to several thousand square miles and blanketing the lowest atmosphere of Earth through the night, unnaturally trapping heat. Some argue that contrails have no effect on the environment but evidence indicates this opinion is not valid. Several solutions to the problem exist. Jets could fly at different altitudes, or engine standards could be raised so that insurance rates are less for those that are friendlier to the environment. Knowledge from the military stealth aircraft program could be incorporated into civilian aviation to avoid contrails, or contrail forecasts could be incorporated into flight planning process so that contrail-prone routes and altitudes are avoided. Contrary to some opinions, contrails have indeed helped raise the temperature of North America and the entire planet since the start of the jet age and continue to do so, making a long-term plan to reduce them a plan that needs to be initiated.
Tests were performed with a NASA jet aircraft examining the effect of sulfur levels in jet fuel exhaust. During the airborne test one engine was run on normal jet fuel and the other engine was run on fuel that emitted exhaust with a lower sulfur content. The high sulfur engine, representing most jet engines on modern commercial aircraft, produced a contrail that lasted through a larger range of temperatures and formed faster out of the engine. The low sulfur engine did the opposite. “Aircraft generate an invisible aerosol trail which enhances the background level of condensation nuclei, in particular regions with dense air traffic at northern latitudes and near the tropopause”6. This condensation nuclei is the tiny matter that gives water vapor the ability to form. The International Civil Aviation Organization is in favor of making polluting, obsolete aircraft uninsurable.
Global warming is already a concern, and although the extent to which contrails are contributing to global warming is debatable, it cannot be argued that they have no effect.
Originally posted by Afterthought
To those who are saying that contrails are doing nothing to the environment, you're dead wrong.
But threads like this sometimes make it seem like contrails are the only problem, or the worst problem. Really there's a lot of uncertainty, but it's generally considered to be a pretty small component of the problem.
But global dimming has reversed over the last 20 years.
Since the year 1950 there has been a slow yet steady drop in solar radiation, in fact the level of radiation reaching the surface of our planet has dropped by 9% in Antarctica, 10% in the USA, 30% in areas of Russia and by 16% in parts of Britain. Overall the average drop in solar radiation has been estimated to be a staggering 22%, an amount which climate scientists consider to be “enormous” and which may present a grave danger to our environment.
The cause of Global Dimming has been found to be changes in the earth’s atmosphere due to the fact that almost anything we do to gain useful energy creates pollutants.
Tracking the brightness of Earth by looking at its reflection on the Moon, scientists have concluded that sunshine on Earth brightened in the 1990's, then dimmed after 2000.
Using a small telescope at Big Bear, the astronomers have for the past five years measured the relative brightness of the two sides of the Moon, which tells how much light is bouncing off Earth back into space, what the scientists call ''earthshine.'' The reflectivity is largely a measure of clouds, which are much shinier than the ocean or ground. Thus, a brightening of earthshine means a dimming on Earth's surface, because less light is reaching the ground.
I'm not against altitude modulation to reduce contrails, I just don't think the science is there yet. It's not clear if it will improve climate change, or make it worse. It's not clear how much it will cost. It's not clear what the pollution impacts are.
I do buy lack of knowledge on the relationship between global dimming and global warming and that, by reckless polluting, the military may have gotten us into a catch-22 situation. I don't buy the sudden and abrupt rise in pollutants in the atmosphere that fly in the face of prior prediction and modeling studies. The extra stuff came from somewhere and that's what we're on the hunt for.
The output of the Sun varies only slightly, so scientists theorize that global dimming probably results from air pollution. Some light bounces off soot particles in the air. The pollution also causes more water droplets to condense out of air, leading to thicker, darker clouds, which block light. For that reason, the dimming appears to be more pronounced on cloudy days. Some less polluted regions have experienced little or no dimming.
The latest updates on solar radiation
changes observed since the new millennium
show no globally coherent trends anymore (see above
and Fig. 2). While brightening persists to some extent
in Europe and the United States, there are indications
for a renewed dimming in China associated with the
tremendous emission increases there after 2000, as
well as unabated dimming in India (Streets et al. 2009;
Wild et al. 2009).
We cannot exclude the possibility that we are currently
again in a transition phase and may return to
a renewed overall dimming for some years to come.
On the one hand, air pollution mitigation potential is
approaching saturation in many of the industrialized
nations (Ruckstuhl et al. 2008; Streets et al. 2009),
thus confining further human-induced brightening
in these areas, while on the other hand air pollution
increase and associated dimming may continue for
a while in developing and emerging nations. The
recent renewed increase in global sulfur emissions
(particularly originating from Asia) (Streets et al.
2009), the evidence for renewed declines in visibility
(Wang et al. 2009) and in satellite-derived SSR
(Hinkelman et al. 2009; Hatzianastassiou et al. 2011),
and the lack of warming in the early 2000s may be
interpreted as additional indicators for such a development.
However, such renewed dimming and associated
impacts would likely have a limited persistence,
since emerging nations will be forced to implement
air quality measures in face of increasingly pressing
health problems. Thus, with the foreseeable inevitability
and undisputable necessity for clean air regulations
and aerosol reductions also in emerging nations,
potential dampening of global warming by a renewed
dimming could only be temporary, and greenhouse
gases will ultimately become the sole major anthropogenic
forcing factor of climate change.
The longer term trend is brightening as pollution controls are implemented.
No. Things dimmed from 1950 through the 1980's. In the 1990's they supposedly brightened. Now they are dimming again. What long term brightening trend? Even the brightening in the 1990's is questionable because it was done by country!!?? Some countries dimmed and some brightened!
We promote simple land-management changes which can reduce global warming, stabilise rainfall, reduce flooding and help prevent famine over the next 10-50 years.
•Our methods are based on mainstream scientific research into land-atmosphere interactions - in particular, the role of clouds.
•We work with academics, communities, NGOs, social enterprises and governments.
How can clouds help cool the planet?
Low level clouds reflect the heat of the sun. Thunderstorm clouds also transport heat from the earth by convection and then radiate it out into space. These clouds can be encouraged to form naturally by increasing soil moisture and vegetation.
How is it done?
Soil moisture can be increased by rainwater harvesting (catching rainwater and helping it percolate into the soil). Other helpful soil moisture interventions include permaculture, conservation agriculture, agroforestry, farmer-managed natural reforestation, soil and water conservation. When done on a large scale, this will increase soil moisture, plant growth, cloud cover and rainfall.
Where can it be done?
This can be effective in hot, semi-arid countries which have a rainy season, especially in parts of the tropics where there has been deforestation. The most promising region is West Africa. Other locations in the northern hemisphere are Florida, India, Ethiopia.
In the animation below, the red, orange, yellow and green areas show where this can be most effective, and at which times of year.
How much cooling impact can this have?
The project is not concerned with CO2 and the greenhouse effect, and it does not allow us to stop our efforts to reduce our greenhouse gas emissions. However, it does buy us more time - potentially delaying the effects of increased global warming by 10-20 years.
Can we be sure it will work?
The project is supported by mainstream scientists from around the world, such as Professor Peter Cox, Met Office Chair in Climate System Dynamics at Exeter University (see his letter of support). A science dossier (pdf, 7MB) with 112 references to peer-reviewed scientific journals is avaliable for download.
What stage is the project currently at?
We have made links with a number of scientists around the world who support the project and want to contribute. We are keen to attract new supporters and collaborators, especially in fields such as: hydrology, meteorology, and other earth-sciences. We have made links with NGOs, and a social enterprise, Kinomé, is working with communities in Senegal on full scale implementation, as part of their Trees & Life project.
Originally posted by Afterthought
It appears that the more we dig, the clearer it becomes that countries are not just talking about geoengineering and have moved onto actually conducting geoengineering and it has simply gone unannounced to the public. Through the private sector and universities, they are going ahead with their plans.
In the United States, four different synthetic fuel projects are moving forward, which have publicly announced plans to incorporate carbon capture and storage:
1.American Clean Coal Fuels, in their Illinois Clean Fuels (ICF) project, is developing a 30,000-barrel (4,800 m3) per day biomass and coal to liquids project in Oakland, Illinois, which will market the CO2 created at the plant for enhanced oil recovery applications. By combining sequestration and biomass feedstocks, the ICF project will achieve dramatic reductions in the life-cycle carbon footprint of the fuels they produce. If sufficient biomass is used, the plant should have the capability to go life-cycle carbon negative, meaning that effectively, for each gallon of their fuel that is used, carbon is pulled out of the air, and put into the ground.
2.Baard Energy, in their Ohio River Clean Fuels project, is developing a 53,000 bbl/d (8,400 m3/d) coal and biomass to liquids project, which has announced plans to market the plant’s CO2 for enhanced oil recovery.
3.Rentech is developing a 29,600-barrel (4,710 m3) per day coal and biomass to liquids plant in Natchez, Mississippi, which will market the plant’s CO2 for enhanced oil recovery. The first phase of the project is expected in 2011.
4.DKRW[who?] is developing a 15,000–20,000-barrel (2,400–3,200 m3) per day coal to liquids plant in Medicine Bow, Wyoming, which will market its plant’s CO2 for enhanced oil recovery. The project is expected to begin operation in 2013.