Geo-engineering refers to set of emerging technologies that could manipulate the environment and partially offset some of the impacts of climate change.
Geo-engineering is the broad-scale modification of a certain process essential to managing Earth's climate for a particular gain. The quantity of solar radiation that Earth receives and how this energy is distributed within the Earth system, and how much of it is absorbed by the surface of the planet and how much is reflected back into space, all affect global temperature.
These techniques fall primarily under three categories
Solar radiation management (SRM)
carbon dioxide removal (CDR)
Increasing the reflectance of incoming solar radiation- SRM
Several factors regulate the reflectance of solar radiation, including the albedo of the Earth's surface, the cloud cover, and the presence of greenhouse gases such as carbon dioxide in the atmosphere (CO2). Geoengineering projects must deliberately change the relative influence of one of these regulating systems if they are to have any significant impact on the global climate.
Raising the albedo (surface reflectance) of a material has been shown to redirect some of the energy that otherwise would be absorbed.
Injecting sulphur particles
The consequences of sulphur injection, according to supporters, would largely match those that occur during volcanic eruptions. This idea was inspired by the Mount Pinatubo eruption in the Philippines in 1991, which released enormous volumes of sulphur dioxide (SO2) and particulate matter into the atmosphere. Over the next several years, it was claimed that this aerosol layer dropped global average temperatures by roughly 0.5 °C.
The process of cloud whitening relies upon towering spraying devices placed on land and mounted on oceangoing vessels. A mist of compressed seawater droplets and dissolved salts would be released from such devices to heights of up to 300 metres (1,000 feet). As the water droplets evaporate, proponents believe, bright salt crystals would remain to reflect incoming solar radiation.
Orbital Mirrors in Space
This proposal involves the placement of several million small reflective objects beyond Earth’s atmosphere. It is thought that concentrated clusters of these objects could partially redirect or block incoming solar radiation.
Carbon dioxide Removal
Carbon burial, more commonly known as carbon capture, utilisation, and storage (CCUS), involves the pumping of pressurised CO2 into suitable geological structures deep underground or in the deep ocean.
Ocean fertilisation, which some scientists refer to as bio-geoengineering, would entail dissolving iron or nitrates into the surface waters of certain ocean areas in order to stimulate phytoplankton growth. Ocean fertilisation would increase the uptake of CO2 from the air by phytoplankton, microscopic plants that reside at or near the surface of the ocean. The premise is that the phytoplankton, after blooming, would die and sink to the ocean floor, taking with them the CO2 that they had photosynthesized into new tissues.
Biochar is a very stable form of carbon generated from the low-temperature pyrolysis of biomass. Multiple advantages have been attributed to the incorporation of biochar into soil, including an increase in agricultural output, nutrient and water usage efficiency, and various environmental benefits. organic nature, relatively higher carbon content and easily available feedstock make biochar a highly sustainable and quick option for carbon sequestration into the soil. Biochar application into the soil not only helps in carbon sequestration but also provides a better option for managing agricultural residues. Due to its priming effect, biochar treatment has also been observed to significantly reduce methane and nitrous oxide emissions from the agricultural land.
Direct Air Capture
Direct air capture (DAC), another method of carbon capture, would include the installation of scrubber towers and so-called artificial trees. In the scrubbing tower approach, wind-powered turbines would direct air into a vast restricted area inside the towers. As the air enters, one of many chemical compounds, such as sodium hydroxide, potassium hydroxide, or calcium hydroxide, would be sprayed into it. These chemicals would react with the CO2 in the air to precipitate carbonate salts or react with water to form weak acids.
It is important to highlight that there is much discussion around each of these plans, and it is difficult to determine their viability. Their worldwide implementation would undoubtedly be challenging and costly, and small-scale tests would provide little insight into their potential efficacy.
Set of cutting-edge technologies just like geoengineering have the potential to alter the environment and partially mitigate some of the effects of climate change. These methods could not be a replacement for reducing emissions (mitigation) or coping with a changing climate (adaptation); yet, they could supplement these efforts.