Solution to prevent sea level rise

Recent research shows that about 150 million people may be affected if the sea level rises by up to 70cm by the end of the century. Sea level rise will inundate coastal lowland areas, including some of the world's largest cities.

Scientists at Normal University in Beijing, led by John Moore, point out that, to combat global warming, humans need to focus on cutting greenhouse gas emissions, rather than relying on into geotechnical solutions.

Sea level rise will flood many lowland areas in the world.
(Photo: Internet).

Dr. Svetlana Jevrejeva, co-author of the study, said: " Alternative geotechnical solutions for controlling greenhouse gas emissions can lead to a burden for the next generation with great risks ."

Geotechnical solutions have been considered to counteract the effects of climate change. These studies received the support of many celebrities such as Bill Gate.

Dr. Jevrejeva said that options such as installing cosmic mirror systems, or spraying small particles of dust into space can only solve the tip, because greenhouse gases still exist in the atmosphere.

This study examined two geotechnical processes with 5 different scenarios.

The first procedure is to reduce solar radiation to the earth's surface by spreading SO ₂ dust into the stratosphere. It can be replaced by launching giant mirrors into orbit.

The second process is to modify the carbon cycle by planting forests, transferring organic matter to charcoal, or using renewable energy made from biological sources (bioenergy).

The study used a model that uses tidal measurements for 300 years to re-represent sea level responses with the change in the heat from the sun to the earth, with the phenomenon of reducing the earth's temperature due to volcanic eruptions, and with human activities.

Then, use this model to simulate sea level under the influence of geotechnical solutions in the next 100 years. The results show that, when applying these processes separately, sea level is still rising strongly.

Dr. Jevrejeva said that the most effective process is to combine all three methods to change the carbon cycle, because these methods are based on biological mechanisms to remove carbon dioxide in the atmosphere and store in the lower biosphere. Biomass, soil, or geological structures.

Scientists come up with many different ways to reduce the greenhouse effect
and the climate is heating up (Photo: BBC)

For example, afforestation will reduce the concentration of CO ₂ in the atmosphere, but only reduce by 45ppm, much lower than human emissions. Turning organic matter into charcoal can reduce 35ppm. The production of biofuels is more effective. Combining all three methods can reduce the concentration of CO ₂ in hard to 250 ppm, and limit sea level rise from 20cm to 40cm.

Carbon storage technology also has many advantages, reducing the concentration of CO ₂ in the atmosphere.

But methods to reflect sunlight back into the universe do not reduce CO ₂ concentrations. If space mirrors are used, there will be technological difficulties and very expensive. The method of using SO ₂ dust in the stratosphere is also controversial. Although the use of SO ₂ can reduce global temperatures by 1 ° C for decades, CO ₂ concentrations remain the same.

Simulations show that spraying SO ₂ dust in the stratosphere is similar to the impact of large volcanic eruptions, occurring at a frequency of 1.5 years. Besides reducing the earth's temperature, this method can slow the sea level rise by 40 to 80 years.

During volcanic eruptions, the effect of lowering the earth's temperature is lowering the sea level. The study used scenarios, corresponding to the amount of dust equivalent to the largest eruption in the 20th century, the eruption of volcanic Pinatubo, Phillipin 1991. Dust particles from volcanic ash moved to the stratosphere and reflected. radiation from the sun, but the amount of carbon dioxide remains in the atmosphere.

No one can know whether bringing SO ₂ dust into the stratosphere can affect the ecosystem? The National Academy of Sciences (PNAS) report showed that spraying SO ₂ dust into the atmosphere easily leads to undesirable consequences such as changing the rain cycle, ozone concentration in the stratosphere, and not doing Reducing the amount of CO2 absorbed by the ocean leads to an increase in acidity in seawater.

This controversial method was tried on a small scale in Russia, using small planes to spray dust. " The SO2 layer in the stratosphere can effectively reduce the earth's temperature, and is a cheap way to combat climate change, " said Professor Yuri Israel from Russia.

But many oppose geotechnical technologies, one of them is Sir David King, chairman of the UK scientific advisory council. " What worries me is that technology is cheap and feasible, just any country that has a rocket is able to bring dust to the stratosphere. We don't trust models that simulate the processes of dust there ".

Imagine, if dust can create more dust in the stratosphere (because there are many chemical compounds there, including ozone), at some point more than is expected to lead to cold earth. gradually, while we want a stable temperature. Sir David explained.