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| Rune Fisker |
By mid-century most cars and buses should run on renewable energy, but bicycles, trains, and our feet will have little impact on the climate. flight to.
There is no guarantee that the industry will get there, but the technology developed to pursue the goals will transform aviation, whether they achieve them or not.
In the years leading up to the pandemic, aviation emitted about 1 billion tons of carbon dioxide annually. This is the same amount as the entire South American continent in 2021. Numbers are recovering as passengers return to the sky. But major airlines, including the six largest U.S. airlines, have committed to achieving net zero carbon emissions by 2050. -Period Goals”. We have ambitious global goals. ”
"Ambition" is an adequate word. The aviation industry is what experts call the most difficult sector to cut. In other words, there is currently no market-acceptable technology that can significantly reduce carbon emissions. The 'net' qualifier that accompanies the target says that the CO2 airlines continue to emit can be explained by using much-criticized conventional carbon offsets or by capturing carbon directly from the atmosphere. . . meaning
Scientists have also discovered that contrails (the wispy, short-lived clouds that sometimes appear in the wake of airplanes) affect the Earth's temperature. It all gets complicated given that he expects global air travel demand to double in the next 20 years.
But new technologies are under development, including hydrogen-powered aircraft, fully electric aircraft, and synthetic jet fuel made from carbon extracted from the atmosphere. Several airlines have begun adding small amounts of cleaner-burning biofuels, known in the industry as sustainable aviation fuel (SAF), to their regular fuel supply. This trend should accelerate. . Many companies are investing to improve the efficiency of their emissions reductions ahead of government regulation. Still, in some cases they are betting big on long-term innovations that can significantly reduce future emissions. gain. get.
``The system is so inert that it has to start decades ahead,'' said Stephen Barrett, a professor of aerospace engineering at the Massachusetts Institute of Technology and president of the Massachusetts Institute of Technology.
But the move hasn't gone as fast as hoped, said Pedro Pires Cabezas, senior economist and his senior director of global transportation at the Environmental Defense Fund, a New York-based nonprofit environmental group. says. get.
He said delegates to the October meeting had yet to adopt a concrete plan to reach the 2050 target. Dr. Piris-Cabezas said:
Transition to Alternative Fuels
Airlines are already investing in improvements that will pay off in the relatively short term, such as retiring older aircraft, finding more efficient routes and allowing planes to run on only one engine, he said. said.
Another short-term innovation he has is sustainable aviation fuel. This is most often a biofuel made from used cooking oil or similar biomass. SAF can produce less carbon dioxide over its life cycle than when mixed with conventional jet fuel. However, SAF production remains limited and expensive, so airlines are slow-moving and mixing small amounts into existing fuel supplies at specific locations.
But there is a lot of enthusiasm within the industry.
JetBlue Airways Head of Sustainability and Environmental and Social Governance Sarah Bogdan said: The choice of airport is no accident. One of SAF's few major suppliers, he has a production facility in California, and the state has introduced low-carbon fuel standards to encourage her SAF and other alternatives.
United Airlines is also focusing on some of its California flights to use SAF. The company's chief sustainability officer, Lauren Riley, said that since 2016, he has integrated SAF on all United flights departing from Amsterdam's Schiphol Airport. He said. United Airlines has also brought together a group of companies such as Deloitte, Nike, and Siemens to help the airline cover its SAF surcharge for business travel.
“Buying sustainable aviation fuel costs him twice to four times as much as conventional jet fuel,” Riley says. "We can't afford it alone."
Riley added that in some years SAF accounted for less than 0.1% of United Airlines' total fuel supply. This number applies across the industry. United Airlines and JetBlue Airways are among more than 20 airlines that have joined a coalition led by the World Economic Forum that pledged to allocate 10% of aviation fuel supplies to SAF by 2030.
But Dr. Piris-Cabezas said it's important to prevent the risk that the cooking oil allegedly used to make SAF, for example, isn't the freshest palm oil you've ever seen in your kitchen. I am warning you. Did it. under. In such a situation, his biomass-based SAF could have adverse effects by promoting the deforestation of monoculture plantations.
He classified his SAF, currently in circulation, as "opaque," noting that consumers may want clarity from airlines.
the force from the atmosphere
Transparency aside, there are major barriers to mass production of his SAF, says Andreas Schaefer, director of the Air Transport Systems Laboratory at the College of London University. Amount of fuel required by aviation. (Dr. Schaefer added that SAF is a misnomer. The fuel still emits carbon dioxide, so "it should be a more sustainable aviation fuel," he said.)
Scientists are investigating alternative carbon sources for SAF, including algae, garden trimmings, and food waste. But perhaps the most interesting potential source is the air we breathe. Of course, it's full of carbon dioxide.
Researchers have already developed technology for this process, known as 'power to liquids'. It uses a giant fan to remove carbon dioxide from the atmosphere, extracting the carbon from the carbon dioxide molecule and combining it with hydrogen produced by electrolysis of water powered by renewable energy. The result is a hydrocarbon that can be used to power an airplane.
"This is promising," Dr. Schaefer said.
That cost is primarily due to the vast amount of clean energy required to produce the bulk of the fuel. But with the cost of renewable energy falling so rapidly, by 2035, "power-to-power" fuel could be cheaper to produce than most of his SAFs made from biomass. I have. . .
Since at least the Cold War, he had his one innovation in mind. An airplane powered by hydrogen. But the engineering challenge here is significant. Hydrogen as a gas is too large to be stored onboard in useful quantities and must be cooled to minus 253 degrees Celsius (approximately minus 423 degrees Fahrenheit), the temperature at which hydrogen condenses into a liquid. Cryogenic infrastructure for fuel supply and storage will also need to be built in airports around the world.
But the technology exists. NASA and the European Space Agency have long used this technology successfully.
Electric flight is another low-carbon option for him. Due to current limitations in the batteries that power the engines, all-electric aircraft lack the energy to propel large aircraft over long distances, but offer a solution for smaller aircraft flying short distances. . Norway seems to be ahead in this regard. According to Norwegian airport operator Avinor, all domestic flights must be fully electric by 2040. Start service by 2026.
Cold Weather Culprit
The aviation industry has focused on reducing carbon emissions, but some academics say reducing the climate impact of flying is easily achievable. Contrails are known to have a significant effect on the temperature of the Earth.
Dr. Barrett of the Massachusetts Institute of Technology said:
According to Dr. Barrett, the science is complicated because he says the effects vary at different times of the day. At night, contrails trap heat radiating from the Earth, leading to further warming. During the day, however, contrails release the sun's energy into the atmosphere, providing a cooling effect. But studies show that the overall impact is one of significant warming, with half to three times the impact of the aviation industry's carbon footprint.
Dr. Barrett is working with Delta Air Lines to study how small changes to his flight routes can help. Contrails only form under certain conditions (when cold and wet) and at a narrow range of altitudes. This means it is relatively easy and cheap for airlines to reroute to avoid aircraft.
David, co-director of the University of California, San Diego's Deep Decarbonization Initiative, spoke to Mr. Victor from his university and Dr. Schaefer from London about the importance of addressing the warming impacts of contrails. He repeated the gender. paddy field.
However, regarding industry efforts to reduce carbon, Dr. Victor argued that in an ideal world there would be no carbon offset market.
Dr. Victor says that traditional carbon offsets have a "pretty bad track record of proven quality." "We can offset this garbage flooding the market," he said.
But he stressed that individual decisions would be largely unchanged, and that the entire system would need to change significantly, he said.
"Doing all this catastrophically is not sustainable," said Dr. Victor.
