What can civil aviation do to help save the planet?

Let's start with a few basics . . . Greenhouse gases. . . one of the major components of the assumed problems . . .

"A greenhouse gas (sometimes abbreviated GHG) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range. This process is the fundamental cause of the greenhouse effect.[1] The primary greenhouse gases in the Earth's atmosphere are water vapour, carbon dioxide, methane, nitrous oxide, and ozone. In the Solar System, the atmospheres of Venus, Mars, and Titan also contain gases that cause greenhouse effects. Greenhouse gases greatly affect the temperature of the Earth; without them, Earth's surface would average about 33 °C (59 °F)[note 1] colder than at present.[2][3][4]"
[link to en.m.wikipedia.org]

So the amounts, distribution, and ratios of the above gases are thought to be critical in the temperature regulation of our planet along with two other main factors . . . External radiation and tectonic heat . . . since we have little chance to control tectonic heat sources we can concentrate on external radiation and greenhouse gases . . . Both of which are within the manipulation or influence of the atmosphere where civil aviation is at its best.

To manipulate the heat retained inside the biosphere/lower atmosphere or keeping the heat from being transferred into the biosphere from the sun is the key to averting potential disaster . .

What can civil aviation do to help save the planet??



2) What does it need saving from. . . ?
Answer: Sudden climate change, Toxicity, and/or degradation of natural shields that protect the earth from external harm.

Toxicity

"Ocean acidification is the name given to the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of anthropogenic carbon dioxide (CO2) from the atmosphere.[1] About 30-40% of the carbon dioxide released by humans into the atmosphere dissolves into the oceans, rivers and lakes [2][3]. To maintain chemical equilibrium, some of it reacts with the water to form carbonic acid. Some of these extra carbonic acid molecules split up to give a carbonate ion and two hydrogen ions, thus increasing the ocean’s "acidity" (H+ ion concentration). This increasing acidity is thought to have a range of direct undesirable consequences such as depressing metabolic rates in jumbo squid[4] and depressing the immune responses of blue mussels[5]. (These chemical reactions also happen in the atmosphere, and as about 20% of anthropogenic CO2 emissions are absorbed by the terrestrial biosphere[3], also in the ground soils between absorbed CO2 and soil moisture. Thus anthropogenic CO2 emissions to the atmosphere can increase the acidity of land, sea and air.)"
[link to en.wikipedia.org]

Degradation of natural shields
Ozone depletion

From Wikipedia, the free encyclopedia

Ozone depletion describes two distinct but related phenomena observed since the late 1970s: a steady decline of about 4% per decade in the total volume of ozone in Earth's stratosphere (the ozone layer), and a much larger springtime decrease in stratospheric ozone over Earth's polar regions. The latter phenomenon is referred to as the ozone hole. In addition to these well-known stratospheric phenomena, there are also springtime polar tropospheric ozone depletion events.
The details of polar ozone hole formation differ from that of mid-latitude thinning, but the most important process in both is catalytic destruction of ozone by atomic halogens.[1] The main source of these halogen atoms in the stratosphere is photodissociation of man-made halocarbon refrigerants (CFCs, freons, halons). These compounds are transported into the stratosphere after being emitted at the surface. [2] Both types of ozone depletion were observed to increase as emissions of halo-carbons increased.
[link to en.wikipedia.org]


Sudden Climate change

Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions, or in the distribution of weather around the average conditions (i.e., more or fewer extreme weather events). Climate change is caused by factors that include oceanic processes (such as oceanic circulation), variations in solar radiation received by Earth, plate tectonics and volcanic eruptions, and human-induced alterations of the natural world; these latter effects are currently causing global warming, and "climate change" is often used to describe human-specific impacts.
Scientists actively work to understand past and future climate by using observations and theoretical models. Borehole temperature profiles, ice cores, floral and faunal records, glacial and periglacial processes, stable isotope and other sediment analyses, and sea level records serve to provide a climate record that spans the geologic past. More recent data are provided by the instrumental record. Physically based general circulation models are often used in theoretical approaches to match past climate data, make future projections, and link causes and effects in climate change.
[link to en.wikipedia.org]

3) How can it be used to accomplish the task . . . saving the planet?
Answer: Civil Aviation being the largest segment of aviation can accomplish intervention within the atmosphere probably faster than any other entity based simply on numbers and frequency of opportunity.

Several schemes have been proposed to use the emissions from civil aviation aircraft or the use of the aircraft as a platform to inject different aerosols into the atmosphere . . . troposphere and/or stratosphere . . .

QUESTION: Are these schemes possible, reasonable and would they be effective?

Answer: The most written about mitigation schemes with cost analysis completed are schemes to inject Sulfur Compounds into the lower Stratosphere . . . the amounts of Sulfur Compounds range from a low of one (1) Tg (one million metric tons) to a higher amount of around seven (7) Tg(s) per year. . . this is thought to slow, halt, or reverse global warming basically counteracting the amount of increased CO2 expected to be added to the atmosphere in the coming years . . . in almost every case civilian and military aircraft are suggested as one if not the only rational way to accomplish

Last Edited by George B on 10/04/2012 02:41 PM

One scheme which is not talked about much . . . it doesn't use Sulfur Compounds nor does it use injection into the stratosphere is the following . . . it uses a type of high tropospheric cloud seeding to reduce cirrus clouds and thus reduce the amount of heat retained or reflected back into

Modification of cirrus clouds to reduce global warming

David L Mitchell and William Finnegan
Desert Research Institute, Reno, NV 89512-1095, USA
E-mail: [email protected]
Received 1 April 2009
Accepted 12 August 2009
Published 30 October 2009
Abstract.

Greenhouse gases and cirrus clouds regulate outgoing longwave radiation (OLR) and cirrus cloud coverage is predicted to be sensitive to the ice fall speed which depends on ice crystal size. The higher the cirrus, the greater their impact is on OLR. Thus by changing ice crystal size in the coldest cirrus, OLR and climate might be modified. Fortunately the coldest cirrus have the highest ice supersaturation due to the dominance of homogeneous freezing nucleation. Seeding such cirrus with very efficient heterogeneous ice nuclei should produce larger ice crystals due to vapor competition effects, thus increasing OLR and surface cooling. Preliminary estimates of this global net cloud forcing are more negative than–2.8 W m–2 and could neutralize the radiative forcing due to a CO2 doubling (3.7 W m–2). A potential delivery mechanism for the seeding material is already in place: the airline industry. Since seeding aerosol residence times in the troposphere are relatively short, the climate might return to its normal state within months after stopping the geoengineering experiment. The main known drawback to this approach is that it would not stop ocean acidification. It does not have many of the drawbacks that stratospheric
injection of sulfur species has.

[link to iopscience.iop.org]

Last Edited by George B on 10/04/2012 02:50 PM

There are basically three suggested methods to inject aerosols into the atmosphere via commercial aviation . . .

1) As a fuel additive
2) Through a dedicated spraying system . . . removed from any contact with the engines
3) Through introduction of the aerosols into the post-combustion exhaust stream . . .

NOTE: On first glance . . . 2 and 3 require expensive retrofitting of the aircraft or full time employment of the aircraft for such dedicated purposes . . . thus would not be the best and easiest use of civil aviation to save the planet . . .

Why Sulfur Compounds and Why the Stratosphere . . . ???

Answer: Because nature has already shown mankind how to do it . . . injecting 20 Tg of Sulfur Compounds into the stratosphere in 1991 . . . which was measurable in Optical Density and Temperature reductions worldwide . . .


Content from external source:

Mount Pinatubo is an active stratovolcano located on the island of Luzon, near the tripoint of the Philippine provinces of Zambales, Tarlac, and Pampanga.[3] It is located in the Cabusilan Mountains[3][4] separating the west coast of Luzon from the central plains. Before the volcanic activities of 1991, its eruptive history was unknown to most people. It was heavily eroded, inconspicuous and obscured from view. It was covered with dense forest which supported a population of several thousand indigenous people, the Aetas, who fled to the mountains during the Spanish conquest of the Philippines.

The effects of the eruption were felt worldwide. It ejected roughly 10,000,000,000 tonnes (1.1×1010 short tons) or 10 km3 (2.4 cu mi) of magma, and 20,000,000 t (22,000,000 short tons) SO2, bringing vast quantities of minerals and metals to the surface environment. It injected large amounts of aerosol into the stratosphere – more than any eruption since that of Krakatoa in 1883. Over the following months, the aerosols formed a global layer of sulfuric acid haze. Global temperatures dropped by about 0.5 °C (0.900 °F), and ozone depletion temporarily increased substantially.[7]

[link to en.wikipedia.org]

Last Edited by George B on 10/04/2012 02:58 PM

A consideration of the use of civil aviation for geoengineering purposes is the visibility of existing jet emissions and the possibility of increased visibility of any aerosol injection process . . . the desire is to increase the loss of just enough long wave (infrared) heat energy from the lower atmosphere as well as to possibly reflect some short wave radiation from entering the lower atmosphere to begin with . . .

1) Pre-existing issues already abound regarding persistent contrails and contrails induced cirrus cloud banks which are seen all over the world
2) Engine efficiencies may be altered as a result of fuel additives . . . increasing operational costs . . .
3) The need to fly at higher altitudes to enhance geoengineering results could increase operational costs . . .

A significant question is does the Radiative Forcing of (visible) persistent contrails and the contrail induced cirrus increase, decrease, or have mixed impact on reducing global warming . . . .





Content from external source:

Some cloud types, like low, thick stratus clouds, are very good in blocking the sun but do little to trap heat, while others, like high thin cirrus clouds, let most of the sunlight in but prevent large amounts of heat from escaping into space. During nightime, when there is no sunlight available to reflect, all clouds are a warming influence on the planet.
[link to www.giss.nasa.gov]




Content from external source:

Total climate effects
In attempting to aggregate and quantify the total climate impact of aircraft emissions the Intergovernmental Panel on Climate Change (IPCC) has estimated that aviation’s total climate impact is some 2-4 times that of its direct CO2 emissions alone (excluding the potential impact of cirrus cloud enhancement).[9] This is measured as radiative forcing. While there is uncertainty about the exact level of impact of NOx and water vapour, governments have accepted the broad scientific view that they do have an effect. Globally in 2005, aviation contributed "possibly as much as 4.9% of radiative forcing."[16] UK government policy statements have stressed the need for aviation to address its total climate change impacts and not simply the impact of CO2.[18]
The IPCC has estimated that aviation is responsible for around 3.5% of anthropogenic climate change, a figure which includes both CO2 and non-CO2 induced effects. The IPCC has produced scenarios estimating what this figure could be in 2050. The central case estimate is that aviation’s contribution could grow to 5% of the total contribution by 2050 if action is not taken to tackle these emissions, though the highest scenario is 15%.[9] Moreover, if other industries achieve significant cuts in their own greenhouse gas emissions, aviation’s share as a proportion of the remaining emissions could also rise.
[link to en.wikipedia.org]







Content from external source:

Radiative forcing

From Wikipedia, the free encyclopedia

In climate science, radiative forcing is generally defined as the change in net irradiance between different layers of the atmosphere. Typically, radiative forcing is quantified at the tropopause in units of watts per square meter. A positive forcing (more incoming energy) tends to warm the system, while a negative forcing (more outgoing energy) tends to cool it. Sources of radiative forcing include changes in insolation (incident solar radiation) and in concentrations of radiatively active gases and aerosols.
[link to en.wikipedia.org]






Content from external source:

Aviation and the Global Atmosphere

Positive RF leads to global warming. Yet climate does not change uniformly; some regions warm or cool more than others; and mean temperature does not describe vital aspects of climate change such as droughts and severe storms. Aviation's impacts via O3 and contrails occur predominantly in northern mid-latitudes and the upper troposphere, leading potentially to climate change of a different nature than that from CO2. Nevertheless, we follow the scientific basis for RF from IPCC's Second Assessment Report and take summed RF as a first-order measure of global mean climate change.
Projection of subsonic fleet growth to 2015 (NASA-2015* scenario) results in a best estimate for total aircraft-induced radiative forcing of +0.11 W m-2 in 2015-about 5% of IS92a projected radiative forcing from all anthropogenic emissions that year.
[link to www.ipcc.ch]

Last Edited by George B on 10/04/2012 04:14 PM

I am so confused . . . so contrails can increase global warming but can cool the stratosphere (not necessarily contradictory) . . . but can cool or warm the troposphere at night and warm or cool it during the day . . . ????





Content from external source:

1. Introduction Contrails are aircraft-induced cirrus clouds that may contribute to global warming (Minnis et al. 1999; Fahey et al. 1999; Burkhardt and Kärcher 2011). At high ambient humidity, contrails develop into contrail cirrus with properties similar to thin natural cirrus (Schumann 2002). Such contrails warm the Earth system during night, but may cool during day, in particular for large solar zenith angles (SZA), small particles, and particle habits with strong sideward scattering (Meerkötter et al. 1999; Myhre and Stordal 2001). Contrails tend to cool over dark and cold surfaces and tend to warm over bright and warm surfaces (Meerkötter et al. 1999). Contrails are often optically thin with optical depth (at 550 nm) of about 0.01-0.5 (Voigt et al. 2011). Thin cirrus in general tends to warm while, during daytime, thick cirrus tend to cool. Contrails may form above or below other clouds and are often associated with, or embedded in, thin cirrus (Sassen 1997; Immler et al. 2008). Ice particles in young contrails are typically small (1- 20 mm), and smaller than typical cirrus particles (Sassen 1997; Schumann 2002). Ice particles in contrails are nonspherical. The shape or habit of cirrus crystals varies in a not-well-known manner (Freudenthaler et al. 1996; Yang et al. 2010). Ice particles in young contrails are frozen droplets that may be described as droxtals (Roth and Frohn 1998). Droxtals differ from spheres in their scattering phase functions (Yang et al. 2003). With increasing age, the shape and size of contrail particles may approach that of natural cirrus. All these properties make simple radiation estimates difficult.
[link to technews.tmcnet.com]

Contrails induce a small radiative cooling in the stratosphere (Meerkötter et al. 1999), causing only small differences between instantaneous and adjusted RF for contrails (Myhre and Stordal 2001; Marquart 2003; Hansen et al. 2005; Ponater et al. 2006). Although individual contrails differ from plane-parallel cloud layers (Schultz 1998; Gounou and Hogan 2007), contrails contribute most to RF when being long lasting, in which case they become rather wide.

Last Edited by George B on 10/04/2012 04:17 PM

Here is how they could help out...

Stop spraying "mists" and start spraying hemp seed instead.

That's what.

Seems the research indicates CIC . . . Contrail Induced Cloudiness increases global warming . . . .

[link to spie.org]


Content from external source:

Global radiative forcing from contrail-induced cloudiness


Ulrike Burkhardt and Bernd Kärcher

Climate model simulations, evaluated using remote sensing data, estimate the net radiative imbalance of the atmosphere due to aircraft condensation trails and their effects.

3 November 2011, SPIE Newsroom. DOI: 10.1117/2.1201110.003764

:Radiative Forcin:


Figure 1. Radiative forcing in the year 2002 from contrail-induced cloudiness (CIC), comprising the direct warming effect of contrail cirrus and the response of natural cirrus clouds introducing a cooling.2 For comparison, the radiative forcing from accumulated aviation carbon dioxide (CO2) emissions and the net forcing from other aircraft exhaust species (comprising the effect of nitrogen oxide emissions on ozone and methane as well as direct radiative effects from emissions of water vapor and soot particles) are shown for 2005 conditions.1

Last Edited by George B on 10/04/2012 04:50 PM

Seems the answer to . . . do persistent contrails increase global warming? . . . looks like . . . YES . . . however, now comes the following . . .

Content from external source:


[link to www-pm.larc.nasa.gov]

Solutions? In principle, it may be possible to selectively minimize the creation of late afternoon contrail-Induced cloudiness that will persist during the night, when they would have a net warming effect, while intentionally increasing the formation of contrails early in the day, generating a daytime cooling. Current research is focused on accurately predicting the times and locations at which contrails are likely to persist for long periods of time and spread over wide areas as Contrail-induced cirrus. Such information could help mitigate the negative effects of aviation on regional and global climate by incorporating it into operational air traffic control and routing systems.
[email protected]

Last Edited by George B on 10/04/2012 04:30 PM

I'm talking about Mr. Jane, not Mary Jane.

Mr. Jane don't care to get you high. He will provide all the things that people need: food, clothing, shelter.

Got it . . .

What could possibly go wrong?

Add to the mix the following . . . persistent contrails seem to narrow the range of the Diurnal Temperature Range . . . thus they increase warming at night and decrease warming during the day . . .





Content from external source:

Regional Variations in U.S. Diurnal Temperature Range for the 11–14 September 2001 Aircraft Groundings: Evidence of Jet Contrail Influence on Climate

D
AVID J. TRAVIS
Department of Geography and Geology, University of Wisconsin—Whitewater, Whitewater, Wisconsin
A
NDREW M. CARLETON
Department of Geography and Environment Institute, The Pennsylvania State University, University Park, Pennsylvania
R
YAN G. LAURITSEN
Department of Geography, Northern Illinois University, Dekalb, Illinois
(Manuscript received 26 November 2002, in final form 3 September 2003)

ABSTRACT

The grounding of all commercial aircraft within U.S. airspace for the 3-day period following the 11 September 2001 terrorist attacks provides a unique opportunity to study the potential role of jet aircraft contrails in climate. Contrails are most similar to natural cirrus clouds due to their high altitude and strong ability to efficiently reduce outgoing infrared radiation. However, they typically have a higher albedo than cirrus; thus, they are better at reducing the surface receipt of incoming solar radiation. These contrail characteristics potentially suppress the diurnal temperature range (DTR) when contrail coverage is both widespread and relatively long lasting over a specific region. During the 11–14 September 2001 grounding period natural clouds and contrails were noticeably absent on high-resolution satellite imagery across the regions that typically receive abundant contrail coverage. A previous analysis of temperature data for the grounding period reported an anomalous increase in the U.S.-averaged, 3-day DTR value. Here, the spatial variation of the DTR anomalies as well as the separate contributions from the maximum and minimum temperature departures are analyzed. These analyses are undertaken to better evaluate the role of jet contrail absence and synoptic weather patterns during the grounding period on the DTR anomalies. It is shown that the largest DTR increases occurred in regions where contrail coverage is typically most prevalent during the fall season (from satellite-based contrail observations for the 1977–79 and 2000–01 periods). These DTR increases occurred even in those areas reporting positive departures of tropospheric humidity, which may reduce DTR, during the grounding period. Also, there was an asymmetric departure from the normal maximum and minimum temperatures suggesting that daytime temperatures responded more to contrail absence than did nighttime temperatures, which responded more to synoptic conditions. The application of a statistical model that ‘‘retro-predicts’’ contrail-favored areas (CFAs) on the basis of upper-tropospheric meteorological conditions existing during the grounding period, supports the role of contrail absence in the surface temperature anomalies; especially for the western United States. Along with previous studies comparing surface climate dataat stations beneath major flight paths with those farther away, the regionalization of the DTR anomalies during the September 2001 ‘‘control’’ period implies that contrails have been helping to decrease DTR in areas where they are most abundant, at least during the early fall season.
[link to facstaff.uww.edu]

Last Edited by George B on 10/04/2012 04:37 PM

My bottom-line conclusion regarding visible persistent contrails and contrail induced cirrus cloud banks is . . . (on a global geoengineering scale) they (persistent contrails and contrail induced cirrus cloud banks) generally increase the retention of long wave heat energy in the troposphere . . . and thus contribute to global warming . . . however, on a local scale . . . say over a city, they may decrease high temperatures during the day and increase temperatures during the night . . . or narrow the (DTR) Diurnal Temperature Range . . .

1) Any effort to reduce the rate of climate change would need to include the mitigation of persistent contrails and the contrail induced cirrus clouds . . .

2) Reduce greenhouse gases in general

3) and use some strategy to reduce heat energy from coming into the Troposphere . . . which always turns to creating a man-made volcano . . . that is . . . use commercial aviation to help save the world from cooking in its own soup . . .

Easy remove every person who still buys into this global climate change dis proven crap from the scenario.

Much could wrong . . . acid rain, ozone depletion, reduced precipitation . . . more or less violent weather . . . on and on . . . however, these are much more acceptable than flooding the land where maybe 70% to 80% of the world's population lives. . .

BY getting you all on a plane high in the atmosphere and breaking a few windows.

Very few scientists don't believe there is global warming . . . the real argument is what is causing it and when does it become critical . . . .??

1) What can commercial aviation do today to reduce global warming . . . is simple really . . . Practice contrail avoidance . . . there is much research available on this subject . . . the small amount of fuel burned to accomplish this practice would be well worth the effort . . . according to some research. . .

2) Fly (cruise) above the Tropopause . . . the air is dryer, warmer, and less turbulent . . . than below the Tropopause . . .

3) This next one is not a sure thing, there is some controversy, but burn sulfur laced fuel while in the stratosphere . . . could possibly be accomplished via designated fuel tanks . . .

Very few scientists are funded one way of another by government no warming = no cash.

Look at the rise of eco cars the more they are bought= lower consumption = creeping up prices for magical reasons

the sun controls our planets temperature and then our planet wobbles (to be scientific) Check out

A)0 milankovich cycles

B) CERN cloud experiment

then return with a new thread saying you KNOW as a FACT

So you are saying there is no warming . . .??? If you are you have not lived in areas of the world where glaciers are receding in rapid fashion . . . I have seen it with my own eyes . . . I also see species living in temperature zones where they have never invaded before . . . so can it be a natural cycle . . . sure . . . so is the extinction of dominate species . . . man is a dominate species . . . the difference is we can invent ways to prevent our own extinction . . . at least I hope so !!!!

Ninth USA/Europe Air Traffic Management Research and Development Seminar (ATM2011)

Design of Aircraft Trajectories based on
Trade-offs between Emission Sources

Abstract – Aviation operations affect the climate in several
ways. Carbon dioxide, water vapor and other greenhouse
gasses are unavoidable by-product of the combustion of
fossil fuel. There are indications that persistent contrails
can lead to adverse climate change, although the complete
effect on climate forcing is still uncertain. A flight
trajectory optimization algorithm with fuel and contrails
models, which develops alternative flight paths, provides
policy makers the necessary data to make trade-offs
between persistent contrails mitigation and aircraft fuel
consumption. This study develops an algorithm that
calculates wind-optimal trajectories for cruising aircraft
while reducing the amount of time spent in regions of
airspace prone to persistent contrails formation. The
optimal trajectories are developed by solving a non-linear
optimal control problem with path constraints. The
regions of airspace favorable to persistent contrails
formation are modeled as penalty areas that aircraft
should avoid. The trade-off between persistent contrails
formation and additional fuel consumption is investigated
for 12 city-pairs in the continental United States. The
avoidance of contrails using only horizontal maneuvers
results in a small reduction of contrails with increasing
fuel consumption. When both horizontal maneuvers and
altitude are optimized, a 2% increase in total fuel
consumption can reduce the total travel times through
contrail regions by more than 70%. Allowing further
increase in fuel consumption does not seem to result in
proportionate reduction in contrail travel times. This
trend is maintained even in the presence of uncertainties
in the contrail formation regions such as uncertainties in
relative humidity values computed by weather forecast
models.
[link to www.aviationsystemsdivision.arc.nasa.gov]

_____________

Transportation Research Part D: Transport and Environment (2005)
Volume: 10, Issue: 5, Pages: 421-426
ISSN: 13619209
DOI: 10.1016/j.trd.2005.04.012
Available from linkinghub.elsevier.com
or Find this paper at:
Abstract

It is shown that a substantial fraction of contrails and contrail induced cirrus can be avoided by relatively small changes in flight level, due to the shallowness of ice-super-saturation layers. [link to www.mendeley.com]

Last Edited by George B on 10/04/2012 06:45 PM

what you are saying is that the world has never warmed before and is now entirely due to humans ?

prevention cant happen The world will do what it wants to do and the same as every animal ever we adapt or die

I did not say that . . . I have not attributed the warming to any source . . . I said above that it could be a natural cycle . . . I said that it exists and could become critical in the survival of a dominate species like mankind . . .the difference is we may invent ways to prevent our extinction . . .

Last Edited by George B on 10/04/2012 05:32 PM