What is Geo engineering?

• It refers to deliberate, large-scale intervention carried out in the Earth’s natural systems to reverse the impacts of climate change.
• This involves techniques to physically manipulate the global climate to cool the planet

Solar Radiation Management

• It is a geoengineering technique which aims to reflect a small proportion of the Sun’s energy back into space. This counters the temperature rise caused by increased levels of greenhouse gasses in the atmosphere which absorb energy and raise temperatures. Some proposed techniques include:
  • Albedo enhancement refers to increasing the reflectiveness of clouds or the land surface so that more of the Sun’s heat is reflected back into space.
  • Space reflectors can help block a small proportion of sunlight before it reaches the Earth.
  • Stratospheric Aerosol Injection(SAI) refers to introducing small, reflective particles into the upper atmosphere to reflect some sunlight before it reaches the surface of the Earth.

Limitations in the use of geoengineering technologies

• Although Stratospheric Aerosol Injection can increase sunlight reflection, thereby lowering the amount of heat that enters the troposphere, this method could also affect stratospheric temperatures, ozone production, destruction rates and transport.
• Aerosol sprays, like other commonly used substances such as dry cleaning solvents, refrigerants and fumigants, contain Ozone depleting substances.
• Further, aerosol injections can cause rapid warming, disrupting the water cycle and leading to massive biodiversity loss.

Why in news?

• Several countries have highlighted the need to undertake studies regarding potential risks and benefits of Geo engineering.