The White House is preparing a plan to bounce sunlight into space to reduce the effects of global warming

In order to suppress global climate change, it turned out that the White House Office of Science and Technology Policy (OSTP) is preparing a research plan to adjust the sunlight reaching the earth by reflecting it in space.

White House pushes ahead researching cool Earth by reflecting sunlight

In 1965, the idea of 'reflecting sunlight to reduce environmental impact' had already appeared in the era of President Lyndon B. Johnson. The idea at the time was that it would cost $500 million (about 74 billion yen) a year to raise the reflectance by 1%. It is possible,' was reported.

Since then, the estimated costs have continued to rise, and according to Edward A. Parson, a professor at the University of California, Los Angeles School of Law, as of 2022, it would cost $10 billion a year to lower the global temperature by 1 degree. 7.4 trillion yen). However, it is still significantly cheaper than other climate change mitigation efforts.

Regarding how sunlight is actually reflected, the National Academy of Sciences, the Academy of Engineering, and the Academy of Medicine will announce three plans in March 2021: ``stratospheric aerosol injection'', `` ocean cloud brightening '', and `` cirrus thinning ''. I'm here.

'Stratospheric aerosol injection' is to spray aerosols from aircraft flying in the stratosphere and reflect sunlight into space. According to Professor Parson, the stratosphere is calm, so if you inject a substance, it will last from 6 months to 2 years. Actually injecting aerosol seems to be able to immediately take heat from extremely high temperature parts and delay the occurrence of guerrilla downpours.

One of the candidate materials for use as an aerosol is sulfur dioxide, which is blown out during volcanic eruptions. In fact, the 1991 eruption of Mt. Pinatubo is known to have slightly cooled the Earth's temperature.

In addition, burning coal also produces sulfur dioxide. However, since carbon dioxide is also generated at the same time, it is an ironic state that ``By reducing the use of coal to suppress the cause of global warming, the emission of sulfur dioxide, which was suppressing global warming, was also suppressed.'' CNBC notes that it has become.

'Ocean cloud enhancement' is an attempt to increase the sunlight reflectance of clouds close to the sea surface by scattering sea salt crystals in the air. And 'cirrus thinning' is a method of dispersing ice nuclei by aircraft or drone so that the density is thinner than when cirrus clouds are naturally formed. As the lifespan of cirrus clouds shortens, infrared radiation in the upper atmosphere increases, water vapor in the troposphere and infrared radiation decrease, and the temperature drops.

According to Harvard University professor David Keith, who has been working on solar reflections since 1989, the topic is being discussed more seriously than before.

However, CNBC cautioned that no one is saying solar reflection is the solution to climate change, and that the number one priority remains reducing greenhouse gas emissions.

in Science, Posted by logc_nt