When there's more energy radiating down on the planet than there is radiating back out to space, something's going to have to heat up. David L. Chandler, spokesman for the MIT Office in 2010.
Contrails are the lines of feathery clouds you can see behind Airplanes. They are not harmless, warns Kyle Arnold, an aviation reporter at the Dallas Morning News. He has made headlines with his recent article (Airlines are finally admitting contrails are an environmental problem), which reports that Airlines and Climate Scientists have reached a consensus that those clouds are having a significant impact on the climate because "contrails, short for condensation trails, create clouds that trap heat in the atmosphere at the critical altitude where airliners fly."
To be clear, contrails consist of frozen water vapor and carbon from jet emissions. It is not to be confused with chemtrails, a demented conspiracy theory not worthy of any serious discussion, similar to MTG blaming Jewish Space Lasers for incinerating California forests.
In fact, contrail clouds may be a more significant factor in global warming than carbon dioxide or other fuel emissions, according to a European Union study measuring more than a decade of airline flights. It's part of an emerging field of study in climate science called "effective radiative forcing," which measures the total warming effect instead of the older standard of totaling CO2 emissions.
Contrails are not long-lasting gas, but they have an outsized climate impact.
The MIT Climate Portal describes radiative forcing:
Sunlight is always shining on half of the Earth’s surface. Some of this sunlight (about 30 percent) is reflected back to space. The rest is absorbed by the planet. But as with any warm object sitting in cold surroundings—and space is a very cold place—some energy from Earth is always radiating back out into space as heat.
Radiative forcing measures how much energy is coming in from the sun, compared to how much is leaving. The analysis needed to pin down this exact number is very complicated. Many factors, including clouds, polar ice, and the physical properties of gases in the atmosphere, have an effect on this balancing act, and each has its own level of uncertainty and its own difficulties in being precisely measured. However, we do know that today, more heat is coming in than going out.
Arnold highlights Andrew Chen, an aviation decarbonization specialist at the Rocky Mountain Institute. "Air travel has almost a double-sized impact on global warming than we thought before; Airlines are finally admitting contrails are an environmental problem. The most interesting dynamic is that the airlines shying away from contrails". In fact, big-name aviation players such as American and Southwest are pairing with other carriers to "get a handle" on the problem. The plane manufacturers Boeing and Airbus have also joined the group. Delta Airlines has partnered with MIT. And Google Research is involved as well.
The airline industry has set ambitious environmental targets in recent years even after admitting that much of the technology to hit those goals doesn't exist yet. American Airlines and Southwest Airlines set a 2050 date to cut their emissions footprint entirely. To date, most of the emissions reductions that airlines have been able to achieve have been through using more fuel-efficient engines while waiting for a sustainable aviation fuel industry using recycled oils to emerge and research on hydrogen and electric engines.
The year twenty-fifty and net zero is just greenwashing. We don't have decades; we are out of time now. To be fair to the parties attempting to solve this problem. There is no existing technology that would dampen the impact on the climate.
Emission reductions in the industry have been by using more efficient engines. The industry is “waiting for a sustainable aviation fuel industry using recycled oils to emerge and research on hydrogen and electric engines."
About 65% of jets flying at cruising altitudes of 30,000 to 38,000 feet create contrails, but most of those contrails dissipate within a few minutes and have little warming effect, according to Delta. About 10% of those are "persistent" contrail formations, hanging around for hours.
Contrails form the easiest at altitudes where planes fly the most efficiently because the air is thin.
But whether or not a plane makes contrails depends on a variety of factors, including temperature, altitude and humidity.
The worst contrails happen at night when the earth is naturally cooling without sunlight but manmade clouds at that critical altitude can block heat from escaping, Chen said.
"A small percentage of flights are happening at night, but those are creating the most contrails," Chen said. "And that's the worst time for it to happen."
Numerous complications in piloting a plane include factoring in weather, turbulence, and speed. "It's tough to weigh the impact of radiative forcing versus carbon dioxide from fuel burn."
The Washington Post weighs in on cloud formation:
“We have a really tough time simulating with any fidelity how clouds actually behave in the real world,” said Timothy Myers, a postdoctoral researcher at the Lawrence Livermore National Laboratory in California.
But in recent years, scientists have gained increasing clarity on what will happen — and what is already happening — to clouds as the planet warms.
First, the high, wispy cirrus clouds that trap the Earth’s radiation are expected to shift upward in the atmosphere, to lower temperature zones. Thanks to a complicated relationship between clouds and the radiation of the Earth, that will increase the amount of radiation that the cirrus clouds trap in the atmosphere. “When they rise, their greenhouse effect, or warming effect, on the Earth tends to increase,” Myers said.
That result has been known for about a decade, and indicates that clouds are likely to amplify global warming. But just in the past few years, researchers have also discovered that the number of low-level stratus or stratocumulus clouds are expected to decrease as the planet continues to warm. One study, in the journal Nature Climate Change, used satellite observations to discover how cloud formation is affected by ocean temperatures, wind speed, humidity and other factors — and then analyzed how those factors will change as the world warms.
“We concluded that as the ocean warms, the low-level clouds over the oceans tend to dissipate,” said Myers, one of the authors of the study. That means that there are fewer clouds to reflect sunlight and cool the earth — and the change in low-level clouds will also amplify global warming.
Once again, it is the loony factor that digs our collective graves...because everybody loves a good contrail conspiracy theory notes this excellent explanation on the contrail threat.
This diary was corrected to correct the author of the article.