Research

Three geoengineering projects that can repair or break the Earth

From the cultivation of forests with an area from the continent tocalling for rain, scientists began to propose, test, and even implement large-scale geoengineering projects to radically transform the planet. These projects are designed to solve problems such as the growth of deserts, droughts or an excess of carbon dioxide in the atmosphere — all for the sake of fighting climate change. After all, if not us, then who? Nature will take its toll and destroy us.

What is dangerous geo-engineering?

Impact of uncontrolled climate changecosts countries hundreds of billions of dollars a year, because the frequency of extreme weather events is growing, and yields are declining, not counting other consequences. All this leads to the need to introduce radical solutions. However, geoengineering, in particular, faced considerable resistance.

Opponents argue that people do not sufficiently understand the complexity of global natural cycles, and trying to change them will cause more problems than it solves.

Large green walls

One of the projects that are already being implemented inSome, was the creation of green walls on large parts of the planet. They consist of native vegetation and land on the edge of the desert to stop desertification of the surrounding areas. The fact is that the land on the edge of the desert is already subject to drought and is overloaded with the communities living there, which creates a vicious circle and makes the residents fight for survival. Green walls and supporting conditions are designed to rejuvenate the earth, making large areas of the planet more livable.

The two largest walls are the Shelter program.in three northern forests "in China, the length of which is 4,500 km, aimed at stopping the spread of the Gobi Desert, and the 8000 km Great Green Wall of Africa to reduce the Sahara.

The success of these walls depends on tracking.long-term changes in vegetation, and to this end, scientists will rely on decadal satellite imagery and augmented visual interpretation algorithms for image analysis. Collect Earth, a joint project of Google and the UN's agricultural division, has created an open source interface that allows researchers to access all this data.

Sun block

Last year, Harvard scientists conducted a testwhich included sending trace amounts of aerosol — insufficient to have any significant effect — into the Earth’s stratosphere, at an altitude of about 20 km. Aerosols contained sulfate compounds, which can reflect incoming sunlight and reduce global temperature.

In an article published in 2017 in the journalAtmospheric Chemistry and Physics, it is argued that the injection of aerosol into the atmosphere, in fact, simulates the ash plume from a volcanic eruption. And, like the ash plume, being introduced into the atmosphere, the aerosol spreads rapidly and affects large areas of the planet.

Scientists are also exploring the possibility of startinggiant umbrella in space to control the amount of solar radiation that reaches the Earth. This idea was afloat for decades, but only recently received an impetus to development.

For example, in the work of 2018 from the Journal ofAerospace Technology and Management describes the launch of the so-called HSS, or the Huge Space Shield. The plan is to place a thin, wide carbon fiber sheet at the Lagrange point, which is a relatively stable point in the complex gravitational pull of the Earth, the Moon, and the Sun. This sheet will block only a small portion of the solar radiation, but this may be enough to reduce global temperatures below the limit of 1.5 degrees Celsius, as established by the International Panel on Climate Change.

Others want to block the sun by stimulatingcloud formation is a process known as cloud seeding. In order for rain to fall, the moisture in the air must condense, which means that an interesting concept of nucleation (nucleation) will be required for the temperature drop and condensation. In nature, water droplets form around particles of dust, pollen, sea salt, or even bacteria, but scientists have confirmed that compounds like silver iodide or dry ice can also work. The plan is to introduce these substances into the atmosphere over drought-prone areas, thereby increasing cloudiness and precipitation.

CO2 removal from the atmosphere

Direct Air Capture (DAC) isa cocktail of chemicals that are bound to CO2 but inert to other gases. When the air passes through DAC machines, also known as artificial trees, CO2 sticks to chemicals and is released again with increasing energy, which allows it to be captured, stored and processed, or reused. The Swiss company Climeworks has built a single commercial plant dedicated to capturing and resale of carbon dioxide. Its goal is to capture one percent of global carbon dioxide emissions by 2025.

CO2 removal from the atmosphere can be carried out.also by seeding the oceans, which are one of the main carbon sinks on the planet, responsible for removing about 30% of carbon dioxide. The best two ways to do this include iron and lime. Iron fertilizer is designed to stimulate the growth of phytoplankton, which sucks carbon dioxide from the atmosphere and helps put it on the seabed.

In a Korean article published in 2018,The authors reviewed iron sowing experiments over the past 25 years, and concluded that this may be a viable solution. However, they recognize that much more testing is needed. Adding lime will cause a reaction with carbon dioxide already dissolved in the ocean, and turn it into bicarbonate ions, thereby reducing the acidity of the oceans and making them susceptible to absorbing more carbon dioxide.

Is the medicine worse than the disease?

Although these ideas seem promising, there isa range of potentially harmful effects. In 2008, 191 countries approved a UN ban on the fertilization of the oceans due to fears of unknown side effects, such as changing the food chain or creating regions with low oxygen concentrations. The Legislative Assembly of Rhode Island passed the 2017 Geo-Engineering Act, which stated that “Geo-engineering includes many technologies and methods related to hazardous activities that can harm the health and safety of people, the environment and the economy of the State of Island. "

Despite resistance, some companiesGovernments are lobbying for geo-engineers to work, and scientists are continuing to develop and experiment with new ideas. Some of the alleged benefits of such plans are being questioned. A recently published article in the journal Nature states that reducing the amount of solar radiation that reaches the surface of the earth will not help much to stop the harmful effects of climate change on crops.

The only question is, do we know enough todo geo-engineering? What if, for example, large-scale cloud sowing changes the flow and slows down the monsoon season in Southeast Asia? How will this threaten rice crops? Or what if dumping tons of eze into the ocean destroys a population of fish along the coast of Chile?

No one knows for sure what consequences such geoengineering projects will have - but it is also possible that they will become the solutions we were looking for.

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