Using computer modeling, American scientists have shown how dangerous artificial regulation of the Earth's climate can be using geoengineering technologies. The results of the study, published in the journal Nature Ecology & Evolution, suggest that such measures will lead to a significant shift in climatic zones, and the consequences of this can be catastrophic for some species of living organisms and reduce biodiversity on the planet.
Scientists have long considered the use of geoengineering technologies, or artificial climate control, as one of the possible measures to combat negative climate changes on Earth (including global warming). With this approach, first of all, a change in the chemical composition of the atmosphere and the world ocean is proposed. In addition, the method of solar geoengineering was considered, which, in theory, should help reduce the amount of sunlight entering the planet by spraying special aerosol compounds in the atmosphere. The sad truth is that, in addition to positive changes, such measures can have serious negative consequences, not only for the climate, but also for many living things on Earth.
To assess the potential risks from the use of solar geoengineering, American climatologists, led by the University of Maryland professor Christopher Trisos, simulated possible displacements of climatic regions during the beginning and final phases of geoengineering procedures.
In order to find out the level of influence of the changes taking place on the zones of maximum biodiversity, scientists measured the change in climatic rates - the ratio of the rate of change of climatic parameters (mainly temperature and precipitation) over time to the spatial gradient of the same parameter. This indicator tells how quickly and in what direction certain climatic zones will move, and helps to predict where and at what speed one or another species of marine and terrestrial living creatures will have to migrate.
The researchers considered a scenario in which geoengineering processes for spraying in the atmosphere are gradually launched over 10 years (from 2020 to 2030) and with an initial level of 5 taragrams of sulfur dioxide. The process then continues for the next 40 years, and then over the next 10 years, there is a gradual end of spraying.
Scientists estimated climatic velocities (for temperature and precipitation) for the entire surface of the planet, first of all paying attention to those zones in which the greatest biodiversity of species is now noted (such as the tropical oceans or the Amazon basin). The obtained data were compared by climatologists with the scenario of moderate natural climate development.
Analysis of the data showed that the launch and continuation of aerosol spraying will indeed lead to a decrease in climatic rates relative to the current level and stabilization of the climate, however, the termination of this spraying can lead to a sharp acceleration of temperature zones. The rate of these changes will be about 10 kilometers per year. And this is almost twice as much as at present, and, according to forecasts for the future, under natural scenarios of climate change, without the use of geoengineering technologies. In addition, the study showed more than twice the rapid displacement of sedimentary zones.
In this case, the most sensitive to temperature changes will be the oceans in tropical zones, and the maximum rate of displacement of sedimentary zones, according to the simulation results, will be observed in the Amazon basin and in Siberia.
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This is how the map of the displacement of climatic zones will look when the geoengineering procedures are terminated (top: G4 - geoengineering scenario, RCP4.5 - natural scenario). Below is a map of the zones in which, as a result of the termination of geoengineering, sedimentary and temperature zones will begin to shift in different directions (with an angle of divergence of more than 90 degrees).
At the same time, the simulation data showed that with an abrupt cessation of aerosol spraying on about 30 percent of the land, the temperature and sedimentary zones will shift in different directions (differences by more than 90 degrees).
The overall effect of the cessation of aerosol spraying will be as follows: the shift of climatic zones and the level of divergence of sedimentary and temperature regions will accelerate, which will lead to a significant change in the existing ecosystems and, most likely, will cause the mass extinction of a significant number of animal species and plants.
To quantify the impact, the researchers compared the rate of displacement of climatic zones with data on displacement of animal habitats as a result of global warming in the recent past. Comparison showed that for most animals they are about 4-7 times less than the possible rate of displacement of climatic zones when stopped.
Scientists focus on the fact that the results obtained once again confirm the danger of artificial climate change. If humanity nevertheless decides to carry out such procedures, then this must be done with extreme caution, having previously estimated all possible risks. Risks not only for the climate, but also for life on Earth as such.
Earlier studies have shown that the risk of negative consequences from the use of geoengineering technologies can increase dramatically with uneven use. For example, using solar geoengineering only in the Southern Hemisphere could lead to a significant increase in the number of tropical cyclones. If geoengineering is applied only in the Northern Hemisphere, it will reduce the number of cyclones, but at the same time will lead to drought in Africa.
Nikolay Khizhnyak