Global warming said to be a reality. Said to cause extreme weather everywhere. They blame it on carbon emission. The thing that is naturally produced by living being and by enjoying live or trying to live.
Mentioned on Al Gore website:
How Do We Know Humans Are Causing Climate Change?
“1. We know that carbon dioxide is the reason the Earth is warming.”
“2. We know that humans are sending huge amounts of carbon pollution into the atmosphere.”
Carbon dioxide and other gases warm the surface of the planet naturally by trapping solar heat in the atmosphere. This is a good thing because it keeps our planet habitable. However, by burning fossil fuels such as coal, gas and oil and clearing forests we have dramatically increased the amount of carbon dioxide in the Earth’s atmosphere and temperatures are rising.
We’re already seeing changes. Glaciers are melting, plants and animals are being forced from their habitats, and the number of severe storms and droughts is increasing.
But, do you know that carbon is not man made greatest heater? Meet contrails and contrail cirrus:
Greenhouse gas trading in international aviation, however, is not compatible with the Kyoto Protocol. At cruise altitude, apart from CO2 it is above all NOx, water vapour, contrails and cirrus clouds that contribute towards the greenhouse effect. Of these, only CO2 is included in the Kyoto Protocol. The radiative forcing of CO2 represents only a little more than one-third (37 %) of the total radiative effect of all climate-impacting avia-tion emissions (Lee/Sausen 2000).
As a result of aviation, emissions are expelled into the global atmosphere that contribute to climate change and the destruction of the ozone layer. Emissions and expelled particulates alter the concentration of greenhouse gases – carbon dioxide (CO2), ozone (O3) and methane (CH4). They also trigger off the formation of contrails and can encourage the occurrence of cirrus clouds. All of this contributes to climate change (IPCC 1999).
In a Special Report of the IPCC (1999), climatic impact was investigated and compared for three periods of observation (1992, 2015 and 2050). In the case of CO2, not only were aviation emissions at these points in time considered, but also the emissions that have accumulated since 1950. With contrails, on the other hand, only emissions from 1992, 2015 and 2050 were considered on account of their short retention time. It turned out that, for all periods of observation, the radiative forcing of contrails is greater that that of CO2. This can be attributed to the fact that the sensitivity effect of contrails is more intense than the accumulation and growth effects of CO2.
Some also reported disagreement with the report:
We disagree. Our characterizations of clouds and particles closely parallel those of the IPCC report. For example, our draft report said â€ścontrails . . . maywarmthe earthâ€™s surface.â€ť The IPCC report stated that contrails â€śtend to warm the earthâ€™s surface.â€ť We changed â€śmayâ€ť to â€śexpected toâ€ť to match the strength of our statement with that of the IPCC. In addition, our draft report said â€ś. . . cirrus cloud cover tends to warm the surface of the earth.â€ť Regarding cirrus clouds, the IPCC states that â€śOn average, an increase in cirrus cloud cover tends to warm the surface of the earth.â€ť Our draft report stated that â€ś. . . increases in soot tend to warm, while increases in sulfate tend to cool.â€ť This is the same language used in the IPCC report.
Other scientist which agree that man made clouds produce cooling at day, it will heat the earth more at night resulted in net warming.
“Contrails formed due to the emission of water vapour increase the cloud cover in the upper troposphere. Contails lead to a reduction of the solar radiation reaching the surface (surface cooling) but they also enhance the greenhouse effect (surface warming) by absorbing longwave radiation welling up from the earth and atmosphere below. This might result in net cooling or heating depending on the size and optical depth of the ice crystals of which the contrails consist. Contrails thus lead to surface warming at night and generally to surface cooling at daytime. Presently it is estimated that contrails lead to a net warming effect over the full day.“
We show that the radiative forcing associated with contrail cirrus as a whole is about nine times larger than that from line-shaped contrails alone. We also find that contrail cirrus cause a significant decrease in natural cloudiness, which partly offsets their warming effect. Nevertheless, net radiative forcing due to contrail cirrus remains the largest single radiative-forcing component associated with aviation.
“The observation of the transformation of aircraft contrails to cirrus clouds has been reported repeatedly
At about 1100 LT (1500 UTC) on 7 September 2003 the lead author noticed a series of contrails apparently emanating from some point to the southwest of his residence in Silver Spring, Maryland. Some of these had already been converted to cirrus uncinus with fallstreaks and others were being transformed as he watched.
Various authors find that contrail-generated cirrus such as reported here contribute to net regional warming.“
“Effluents emitted by aircraft give rise to changes in atmospheric composition with impact on air chemistry and the radiation field and thus climate. Aircraft emission signatures in the form of aerosols, contrails, NOx and other species are clearly observable on the regional scale. While particle emission and formation as well as NOx emission with subsequent ozone production are likely to exert the most important chemical effects, CO2, contrails and ozone (if confirmed to be affected by aircraft NOx) affect radiative transfer and thus climate. It should be noted that thermal forcing exerted by aircraft effluents and their products is about 3 times higher than that of aircraft CO2 alone, at least for the northern hemisphere. Thus, in view of this triple effect, incentives aimed to reduce global emissions of CO2 should not exclude air traffic if environmental taxes are introduced, in particular as aviation is growing faster than most other fields of the world’s economy.”
Global estimates of the effects of contrails are they contribute to a net warming (Minnis et al. 2004).
Particles, typically of a size less than 10 or 2.5 ÎĽm (PM10 and PM2.5) are of growing concern as they contribute to a variety of health and environmental problems (Dockery, 2009; Hansen & Nazarenko, 2004). Fine particles also cause reduction in visibility (Eidels-Dubovoi, 2002; Bond & Bergstrom, 2006), make lakes and streams acidic, deplete the nutrients in soil, and affect the diversity of ecosystems when settling on ground or water. Moreover, particles have both a direct and indirect effect on the earthâ€™s climate by either scattering or absorbing solar radiation and by acting as cloud condensation nuclei (Jacob, 1999).
A research team of American and German scientists, headed by Patrick Minnis of the NASA Langley Research Center in Hampton, Virginia, reports evidence that contrails cause a warming of the Earthâ€™s atmosphere. Currently their impact is currently small as compared to other greenhouse effects. They predict, however, that it may grow by a factor of six over the next 50 years. The researchers emphasize that these are conservative estimates, which take into account only the thicker contrails that can be readily observed.
For the past 10 years NASA has held a conference on The Atmospheric Effects of Aviation Project (AEAP). Several hundred researchers from around the world attend annually. In 1997 Researchers from NASA Langley Research Center in Hampton, Virginia, presented evidence that contrails are contributing to global warming and causing local effects over areas with heavy air traffic. This was reported by Jim Scanlon a journalist in attendance at the conference. He also reports that Fred Singer held a session where he presented a session that argued that the steady increase in air traffic for the last 20 years was responsible for the nighttime warming detected over North America.
Contrails potential as warming also bring concern of night flight:
“The magnitude and possibly even the sign of the mean net radiative forcing of contrails depends on the diurnal cycle of contrail cover. For the same contrail cover, the net radiative forcing is larger at night. Satellite data reveal a day/night contrail cover ratio of about 2 to 3 (Bakan et al., 1994; Mannstein, 1997).”
The warming effect of contrail cirrus is disproportionally large at night, since at daytime the cooling due to the short wave cloud albedo effect acts toward compensating the long wave warming effect. Therefore it has been suggested to restrict air traffic to daytime in order to reduce its climate impact.
“As a consequence flights during nighttime hours have a disproportionate effect on the diurnal mean contrail radiative forcing. They account for 60 to 80% of the mean contrail climate effect, even though only one in four flights occurs at night. Our results suggest that shifting flights from night-time to daytime could be one measure to minimize the climate effect of contrails.”
“This warming effect is far greater for contrails left by night flights, Stuber added. “The solar cooling effect [wherein contrails reflect the sun's rays back into space] only happens during the day, when the sun is up,” she explained. “During the night the greenhouse warming is no longer balanced, and that is why the contribution of nighttime flights is so large.” Some contrails can last for a day or longer, though they gradually disperse and begin to resemble natural clouds.”
Therefore, the overall net effect of contrails is positive, i.e. a warming effect.
“The terrorist attacks of September 11, 2001 was the aforementioned event, and it was likely to have excited meteorological researchers involved in contrail impact studies. The national airspace was shut down for three days, something that had not yet occurred since the jet age began in the 1960s and is not likely to occur ever again. Scientists took advantage of this unique three day period in history that lacked contrails. What they learned was shocking and is enough evidence to effectively silence any counterargument to their case. One measure of climate is the average daily temperature range (DTR). For thirty years this had been recorded and extra cirrus clouds in the atmosphere would reduce this range by trapping heat. â€śSeptember 11 â€“ 14, 2001 had the biggest diurnal temperature range of any three-day period in the past 30 years,â€ť said Andrew M. Carleton1. Not in three decades had there been such a large temperature spread between the daytime highs and the nighttime lows. Furthermore, the increase in DTR during those three days was more than double the national average for regions of the United States where contrail coverage was previously known to be most abundant, such as the Midwest, northeast, and northwest regions. The specific increase in the range was 2Â°F, which in three days was twice the amount the average temperature had increased by over thirty years time1. This is evidence that contrails do alter the climate of the land they drift above.“
There is testimony that trails also reduce the output of solar panel, the solution for future green energy.
“I live in what is loosely referred to as high mountain desert, elevation some 7500 feet. My off-grid solar was state of the art ten years ago and has been continually upgraded since the initial install. I have tracked amp-hour output religiously all this time and I can testify that overall daily output has been reduced some 20% over the last four years as observed chemtrail activity has incrementally increased during the same four year period. And this is not a result of PV panel degradation. (PV panels over a 20 year period can be expected to degrade 20%)”
Not just as the source of heat, trails is also hamper the solution for clean energy. Trails is a clear enemy for green living.
US Government currently ignore contrails problem.
“While EPA establishes emissions standards for aircraft, the Federal Aviation Administration (FAA) of the U.S. Department of Transportation (DOT) administers and enforces these standards. This domestic framework for regulating aircraft engine emissions is more fully described in Box 2. Currently, there are no regulations addressing contrails and their atmospheric effects. The Clean Air Act (CAA) directs the U.S. Environmental Protection Agency (EPA) to establish aircraft and aircraft engine emissions standards for any air pollutant that could reasonably endanger public health and welfare.”
Contrails is a serious problem now. It is time for anyone who have concern for the earth to put more attention on how to stop contrails. However, this had already been mentioned by scientist since few years ago. Lack of attention could also be because of intentional ignorance.