Question

Provide a brief overview of geoengineering technologies and comment on why they are not more aggressively investigated as climate change solutions?

Answer 1

Geoengineering technologies is a technique used to reduce or prevent drastic climatic changes by reducing or preventing excess solar heat, removing CO₂ Emissions etc... Geoengineering technologies can be categorized by different approaches (solar radiation management, carbon dioxide removal, weather modification), or by where they seek to intervene in the planetary ecosystem (land, air, water). Geoengineering is the idea of applying planetary engineering to Earth. Climate geoengineering refers to large-scale schemes for intervention in the earth’s oceans, soils and atmosphere with the aim of reducing the effects of climate change, usually temporarily. The main categories of proposed geoengineering techniques are,

• Solar Radiation Management: - this technique attempts to reflect sunlight back into space, and include a range of ideas, from orbiting mirrors, tones of sulphates sprayed into the stratosphere, and modifying clouds, plants and ice to make them more reflect more sunlight.
• Co₂removal: - These proposals include if it is possible to suck carbon out of the atmosphere on a massive scale, using a combination of biological and mechanical methods, from seeding the ocean by creating plankton blooms to creating forests of mechanical “artificial trees”.
• Earth Radiation Management: - this suggest that negative effects of climate change can be remove by allowing heat to escape into space.

But the geoengineering is a not a correct solution for climatic crisis or to the climatic changes all around the world. It does not focus on the root of the problem. Some of the geoengineering techniques are Carbon Capture and Storage, Direct Air Capture, Carbon Capture Use and Storage, Stratospheric Aerosol Injection, Ocean Fertilization etc.…

• Carbon capture and storage: - its main objective is to remove or filter Carbon dioxide from land surfaces of earth and store for a long time. This technique is done by extracting carbon dioxide emissions from powerplants, industry etc.… these extracted CO₂ is compressed into liquid and transporting by a pipe line where it can be pumped underground into saline aquifers, under the ocean for a long time. This process is costly and technologically challenging.
• Direct Air Capture: - its main objective is to suck the carbon dioxide emissions such as greenhouse gases are removed directly from the atmosphere. The current technique uses large fans that move ambient air through a filter, using a chemical adsorbent to produce a pure CO2 stream that could be stored. The main disadvantage is that safe and long-term CO2 storage cannot be guaranteed, in geological formations where leakage is a risk.
• Carbon Capture Use and Storage: - this technique main objective is to filter out the carbon and use it for another purpose like manufacturing. CO₂ from either industry or the atmosphere can be used for manufacturing, resulting in CO₂ stored in products. An example involves feeding captured CO₂ to algae which produce biofuels, another is reacting CO₂ with calcifying minerals to produce concrete for building purposes.
• Stratospheric Aerosol Injection: - this aims to solar radiation management by Spray sulphites (it may be Sulphur dioxide) or other particles into the stratosphere (which is upper layer of atmosphere) to block the sun which acts as a reflective barrier to the sun. it is done by shooting particles from artillery guns, using large hoses to reach the sky, or emptying particles from the back of aircrafts. This technique is potential and it can be weaponized. This is one of the main challenges of stratospheric Aerosol Injection.
• Ocean Fertilization: - its main objective is to remove carbon dioxide from the ocean by dumping iron pellets into the ocean to stimulate plankton growth. the resulting phytoplankton draw down atmospheric CO₂ and then die, falling to the ocean bed and sequestering carbon. the idea is that the new phytoplankton will absorb atmospheric CO₂ and, when the phytoplankton die, the carbon will be sequestered as they sink to the ocean floor.

Geoengineering technologies are not more aggressively investigated as climate change solutions because there is some risk in it. First one is environmental science and intended or unintended consequences. The other is one social, political or even military risks. In the case of environmental risks, the offsetting of greenhouse gases by increasing the reflection of sunlight is not going to be perfect. Some people, potentially a small minority, will get less rainfall. There is concern about what particles might do to the ozone layer. The offsetting of sunlight and CO₂ is not perfect. We would expect there to be some impact on ocean circulation. Ocean currents could change dramatically. The environmental risk reduction is by greenhouse gas emission reductions. But emissions and global temperatures keep going up and up. Geoengineering technologies are mostly costly and some of these techniques would no achieve what we are really expecting. There is some risk factor in this techniques such as social, pollical and may be military risks. So, by these reasons Geoengineering technologies are not widely used as climatic change solutions.

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