Geoengineering - the last hope for Earth's climate?

The latest Royal Society report said, unless people reduce carbon dioxide emissions, the future of the Earth is only expected to rely on potentially hazardous and unproven geoengineering measures. .

According to the new report (published by the UK Academy of Sciences, the Royal Society, released September 1), pointed out that unless efforts to minimize greenhouse gas emissions are outperforming compared to Currently, people will need to conduct multiple geoengineering measures to cool the Earth. Geoengineering technology is said to be technically very positive and some of these are useful in supporting efforts to reduce greenhouse gas emissions to prevent climate change.However, the report identifies potential risks related to the efficiency, economic costs and environmental impacts of these measures.

Professor John Shepherd, head of geoengineering research at the Royal Society, said: 'The cruel truth is that unless successful in significantly reducing CO ₂ emissions, we are likely to face a future with harsh and unfavorable climate, then geoengineering will be the only option left to limit the rise in Earth temperature. Our research has shown that some geoengineering techniques can have unpredictable adverse effects on people and ecosystems - however, according to the current situation, we still have not had success. Any way to ensure that in the future will not have to use these measures. The geoengineering technique and its consequences are the price people pay for their failure to prevent climate change. '

The report evaluates two main geoengineering techniques - Carbon Dioxide Removal (CDR) and Sunlight Radiation Control (SRM). CDR techniques attempt to bring the Earth back to normal; they focus on the source of the problem (the amount of carbon dioxide is rapidly increasing in the atmosphere), so it is more certain and less risky. They are considered to be more feasible than SRM measures, although both groups are not yet effective compared to the cost, provided that the environmental impacts are acceptable.

SRM techniques work by reflecting solar energy, preventing them from reaching the ground. This means reducing the temperature of the Earth quickly, but not reducing the amount of CO2. Therefore, they are not effective in addressing the broader effects of increasing CO2, such as acidification, and need to be applied over a long period of time. Although the funding is relatively low, this group of measures still contains significant risks of side effects, and they only reduce some of the effects of climate change, while hiding many potential harms. The report concludes that SRM techniques are only useful when we are forced to rapidly reduce the Earth's temperature, and that this is not a substitute for emissions reduction efforts or CDR measures.

The new report points out that unless efforts to minimize greenhouse gas emissions are far from successful, people will need to take many geoengineering technical measures to cool the Earth. (Photo: iStockphoto / Andrey Prokhorov)

Professor Shepherd notes, 'There is no geoengineering technology that is truly a miracle for mankind, and every measure has its own uncertainties and risks. The most important thing is that we continue to make efforts to cut emissions, and are willing to face the worst case if we fail. In the latter case, geoengineering technology will be the only option for the future. Therefore, it is now necessary to seriously research and develop various measures, their impacts on the environment and related management issues. If using geoengineering measures irresponsibly or neglecting side effects, it is likely that humans will face catastrophic consequences similar to climate change. We need to have a clear management framework in place to prevent this from happening. '

Among the proposed CDR techniques, the following are considered more potential:

• Separating CO ₂ in the air and storing them - this is a geoengineering measure that is of great interest because it directly changes the causes of climate change.

• Strengthening weathering - this is a method of taking advantage of natural reactions of CO ₂ in air with rocks and minerals, and is considered a positive long-term option. However, more research is needed to get the most economical way and understand the possible environmental impacts.

• Land use and afforestation - the report shows that managing land use plays a small but important role in reducing atmospheric CO ₂ levels. However, the scope of application of this measure will be limited by conflicts around land use, and different needs in land use should be considered carefully when assessing the potential of forest production and reforestation.

When temperatures rise to an alarming level and more rapid measures are needed, the following SRM techniques appear to be more satisfactory:

• Spray sulfur into the stratosphere to create sunlight radiation clouds - this is a feasible measure, past volcanic eruptions are short-term preliminary tests for the level effectiveness of this measure. The cost is assessed to be relatively low and the execution time is short.However, there are still many big questions around the side effects that need to be answered, especially the destruction of the stratosphere.

• Measures in the universe - this is considered a feasible SRM technique in the long term if major issues during deployment and maintenance can be solved. Currently, this measure group is still considered to be expensive, complex and time consuming in implementation.

• Measures related to cloud reflectance (albedo) parameters (eg building cloud ships - fleets of ships traveling in the oceans to create large clouds deflecting the sun's rays) - results only local and adverse weather and tidal impacts in the area are issues that need attention. The feasibility and effectiveness of this measure is unclear.Further research should be conducted before seriously considering this measure.

Less feasible techniques:

• Pyrolysis coal (a CDR technique) - the report raised great doubts regarding the scope of feasibility, effectiveness and safety of this technique and recommended that more research be needed. depth before believing this is a reliable measure.

• Ocean fertility (a CDR technique) - the report shows that this technique has not been proven to be effective, and has potential unpredictable marginal ecological effects.

• Measures related to the reflectance parameters of the ground (SRM techniques, including roof white paint, tree planting are able to reflect light and place reflective mirrors in the desert) - these are measures The solution is not very effective, expensive and, in some cases, can cause serious impacts on the weather in the region.