6 Electric Aviation Could Be Closer Than You Think
In 2019 air travel accounted for 2.5 percent of global carbon emissions1, a number that could triple by 2050. While some airlines have started offsetting2 their contributions to atmospheric3 carbon, significant cutbacks are still needed. Electric airplanes could provide the scale of transformation4 required, and many companies are racing5 to develop them. Not only would electric propulsion motors eliminate direct carbon emissions, they could reduce fuel costs by up to 90 percent, maintenance by up to 50 percent and noise by nearly 70 percent.
7 Low-Carbon Cement Can Help Combat Climate Change
Concrete, the most widely used human-made material. The manufacture of one of its key components6, cement, creates a substantial yet underappreciated amount of human-produced carbon dioxide: up to 8 percent of the global total, according to London-based think tank Chatham House.
In 2018 the Global Cement and Concrete Association, which represents about 30 percent of worldwide production, announced the industry's first Sustainability Guidelines, a set of key measurements such as emissions and water usage intended to track performance improvements and make them transparent7.
Quantum computers get all the hype, but quantum sensors could be equally transformative, enabling autonomous vehicles that can "see" around corners, underwater navigation systems, early-warning systems for volcanic10 activity and earthquakes, and portable scanners that monitor a person's brain activity during daily life.
Quantum sensors reach extreme levels of precision by exploiting the quantum nature of matter. Atomic clocks illustrate11 this principle. Other quantum sensors use atomic transitions to detect minuscule12 changes in motion and tiny differences in gravitational, electric and magnetic fields.
9 Green Hydrogen Could Fill Big Gaps in Renewable Energy
When hydrogen burns, the only by-product13 is water—which is why hydrogen has been an alluring14 zero-carbon energy source for decades. Yet the traditional process for producing hydrogen, in which fossil fuels are exposed to steam, is not even remotely zero-carbon.
Green hydrogen is different. It is produced through electrolysis, in which machines split water into hydrogen and oxygen, with no other by-products. Historically, electrolysis required so much electricity that it made little sense to produce hydrogen that way. The situation is changing for two reasons. First, significant amounts of excess renewable electricity have become available at grid15 scale; the extra electricity can be used to drive the electrolysis of water, "storing" the electricity in the form of hydrogen. Second, electrolyzers are getting more efficient.
10 Whole-Genome Synthesis Will Transform Cell Engineering
Early in the COVID-19 pandemic, scientists in China uploaded the virus's genetic16 sequence to genetic databases. A Swiss group then synthesized the entire genome and produced the virus from it—essentially teleporting the virus into their laboratory for study without having to wait for physical samples. Such speed is one example of how whole-genome printing is advancing medicine and other endeavors.
Whole-genome synthesis is an extension of the booming field of synthetic17 biology. Researchers use software to design genetic sequences that they produce and introduce into a microbe, thereby18 reprogramming the microbe to do desired work—such as making a new medicine. So far genomes mainly get light edits. But improvements in synthesis technology and software are making it possible to print ever larger swaths of genetic material and to alter genomes more extensively.
收听单词发音