Earthsky Interviews
Private: Contrails’ effect on warming “big question mark”
05-20-2007 - Earth
Right now, over the U.S., there are more than 27,000 flights a day. Experts say that, as air traffic increases, aviation’s contribution to greenhouse warming will increase. And air traffic is increasing around the world, especially in developing countries such as India and China.
One effect is that when jet engine combustion happens at high altitudes, it can create cloud-like “contrails”:http://en.wikipedia.org/wiki/Contrail. Many scientists think that “contrails contribute to trapping heat”:http://208.96.63.114/?p=2198 in Earth’s atmosphere.
Patrick Minnis: _Greenhouse gases and emissions in the form of water vapor that can change the existing water vapor into contrails can have, what they estimate, is a two to four times greater impact per unit than the same emissions at the surface._
That was “Patrick Minnis”:http://www-pm.larc.nasa.gov/pages/minnis_home.html at “NASA’s Langley Research Center”:http://www.aero-space.nasa.gov/. He said that as contrails dissipate, they act like cirrus clouds, which hold heat in the atmosphere.
Patrick Minnis: _Their impact is still a big question mark. We’re pretty sure that they cause warming, but whether that warming it negligible or whether it’s greater than we expect from the greenhouse gases like CO2 and ozone that are produced by the aircraft exhaust, we’re not sure._
Our thanks today to “NASA’s”:http://www.aeronautics.nasa.gov/ Aeronautics Research Mission.
Our thanks to:
“Patrick Minnis”:http://www-pm.larc.nasa.gov/pages/minnis_home.html
Senior Research Scientist
Climate Science Branch
Science Directorate
NASA Langley Research Center
The thin contrails from jets cause very little, if any, global warming.
Heat rising from below will have no trouble moving through or around these high thin contrails. If there is any affect on climate it would be to cool the earth by reflecting sun light back into space.
It does not take a thick cloud to reflect sun light, but it would take a thick cloud to hold heat in. Take the example of a blanket and a sheet on your bed. It takes a thick blanket (cloud) to keep you warm. While the white sheet (contrails), though not keeping in much heat will reflect light well.
Most of the visable output from a jet engine is condensed water vapor. It is the stuff you don’t see that may be a contributing problem. CO, CO2, sulfur, arsenic and many other compounds from burned and unburned jet fuel may have long term effects on our Earth. These are released at many altitudes up to 45,000 feet (commercial flights). They are carried by the winds aloft and Jet Stream for hundreds of miles. The heavier compounds eventually fall to Earth and get into our water ecosystems. The U.S. Air Force published an interesting article on this subject:
http://www.af.mil/shared/media/document/AFD-051013-001.pdf
The IPCC published this report: http://www.grida.no/climate/ipcc/aviation/041.htm
As a former B-52G aviator and business air traveler, I am very concerned about this issue. Over the past few years I have managed to find alternatives to flying. For my business, I have found that Web conferencing is cheaper and less polluting.
March 25, 2007
Many people are worried about climate change and/or global warming. The news media expounds on this subject along with our elected officials in the U.S. Congress. The drum beat is being heard everywhere that all of us must do something. The question is what?
We now know that persistent jet contrails according to NASA are producing man-made clouds. And this climate change is exacerbating global warming. We also know that there are many atmospheric heating and testing programs being conducted as well. These may also be having an effect on climate.
When you add over 50+ (according to NOAA records) experimental weather modification programs ongoing in the United States the number of events happening in our atmosphere is enormous. We don’t know the synergistic impact of all of these programs on our climate or how all these chemicals are impacting human health, drinking water supplies, and soils.
However, we do know that “global dimming” is taking place and many scientists are beginning to take notice. Without direct sunlilght the photosynthesis process will not take place and plant life and crops won’t grow well. Direct sunlight gives all living plants the energy to grow. And we now have persistent jet contrails that are leaving our skies covered in man-made clouds and white haze that is causing the sun to be dimmed.
When you add the climate change produced from these contrails crop production will be greatly impacted. Our trees here in Northern California and our rangeland grasses are already not growing properly due to the lack of direct sunlight. Whenever we are not raining our skies are so filled with these persistent jet contrails, white haze, and man-made clouds that we rarely have a clear, blue sky day. We have only had three days in Mendocino County, CA, where the skies were blue all day since January 1, 2007.
Our California Governor has declared disaster areas in 31 Counties in California due to stunted rangeland grasses. In Mendocino County, CA, the cause can’t be cold weather or rain as it has been relatively normal here when one researches our weather historically. However, we rarely see the sun and have direct sunlight here…thus, there is a real possibility that the stunted rangeland grass growth is being cause by a lack of sunlight.
We need to address these issues in order to access their impact on climate before we decide to Geoengineer our plant with more atmospheric chemicals like placing sulfur into the atmosphere to cool the planet. We already know that “global dimming” has not cooled the planet and putting more chemicals into our atmosphere to try and dim more sunlight might cause serious harm to our already stressed climate and reduce life giving sunlight from reaching our trees and plants.
It it time to reduce climate change by curbing persistent jet contrails producing white haze and man-made clouds. This could be accomplished in a short time and we could see if this process would reduce the warming of the planet.
If we held public oversight hearing on current weather modification programs (private, public, university, military, NOAA, NASA, DOD, DOE, atmospheric heating and testing programs, and investigated the causes of global dimming, we could begin to grasp how much these programs are impacting our climate. In order to protect agriculture here in the United States it is time to step up and begin to hold public hearing on all of these programs to find out how they are impacting agriculture.
Sincerely,
Rosalind Peterson
Post Office Box 499
Redwood Valley, CA 95470
(707) 485-7520
E-mail: info@californiaskywatch.com
Website: californiaskywatch.com