[Answered] Bring out the application of and implications associated with geoengineering to reduce the impacts of global warming.

Geoengineering is an umbrella term for various experimental technologies designed to deliberately alter the climate system to reduce the impacts of global warming. They are slowly but steadily gaining salience and broadly fall under two categories: Solar Radiation Modification (SRM) and Carbon Dioxide Removal (CDR) technologies.

Applications of geoengineering

SRM techniques aim to reflect a small proportion of the Sun’s energy back into space. This counters the temperature rise caused by increased levels of greenhouse gases in the atmosphere which absorb energy and raise temperatures. Some proposed techniques include:

• Albedo enhancement: Increasing the reflectiveness of clouds or the land surface so that more of the Sun’s heat is reflected back into space.
• Space reflectors: Blocking a small proportion of sunlight before it reaches the Earth.
• Stratospheric aerosols: Introducing small, reflective particles into the upper atmosphere to reflect some sunlight before it reaches the surface of the Earth.

CDR techniques aim to remove carbon dioxide or other greenhouse gases from the atmosphere. It directly counters the increased greenhouse effect and ocean acidification. Some proposed techniques include:

• Biochar: ‘Charring’ biomass and burying it so that its carbon is locked up in the soil.
• Carbon capture and sequestration: Growing biomass, burning it to create energy and capturing and sequestering the carbon dioxide created in the process.
• Ambient Air Capture: Building large machines that can remove carbon dioxide directly from ambient air and store it elsewhere.
• Ocean Fertilisation: Adding nutrients to the ocean in selected locations to increase primary production which draws down carbon dioxide from the atmosphere.
• Ocean Alkalinity Enhancement: Grinding up, dispersing, and dissolving rocks such as limestone, in the ocean to increase its ability to store carbon and directly improve ocean acidification.

Implications associated with geoengineering:

• They may distract attention from the need for deep cuts to gross emissions which is achievable with the right political will and resource mobilization. Such measures thus pose pivotal problems of intergenerational justice.
• Many experts fear that it may impair the self-regulation capacity of natural ecosystems thereby doing more harm in the long run.
• Intergovernmental Oceanographic Commission (IOC), finding is that even over one-hundred years, very large-scale fertilization would remove only modest amounts of CO₂ from the atmosphere.
• There is also an ethical argument that ‘do we have the right to manage and manipulate nature?’

To potentially help mitigate future climate change, geoengineering should undergo more detailed research and analysis. Scientists need to consider the environmental risks of geoengineering and the public and decision makers need to participate in discussions about the ethical, social, and geopolitical constraints of these new technologies.