Why in News ?
Greenland Ice Melting Impact the rise in sea level. The Greenland Ice Sheet (GIS) is melting rapidly faster than at any other time in the last 12,000 years a new study has found.
What is the impact ?
- The increased loss of ice is likely to lead to sea level rises of between 2 centimetres (cm) and 10 cm by the end of the century from Greenland alone.
- Americans use more energy per person than any other nation in the world.
- Largest pre-industrial rates of mass loss up to 6,000 billion tonnes per century occurred in the early Holocene the period since the last ice age 12,000 years ago.
- Studied changes to the southwestern sector of the GIS from the beginning of the Holocene epoch.
- Extending to 80-2100 years using simulations and predicted mass loss of between 8,800 and 35,900 billion tonnes over the 21st century.
- Representative Concentration Pathway (RCP) 8.5 scenario — the one the GIS is now following — the rate of mass loss could be about four times the highest values experienced over the past 12,000 years.
Representative Concentration Pathway (RCP) is a greenhouse gas concentration trajectory adopted by the United Nations Intergovernmental Panel on Climate Change. Projecting future climate change involves assessing a number of different uncertainties.
- Four pathways were developed based on their end-of-century radiative forcing:
- RCP2.6 : Indicating a 2.6 watts per metre squared – W/m2 forcing increase relative to pre-industrial conditions. Requires that carbon dioxide (CO2) emissions start declining by 2020 and go to zero by 2100.
- RCP4.5 : Emissions in RCP 4.5 peak around 2040, then decline.
- RCP6.0 : In RCP 6, emissions peak around 2080, then decline.
- RCP8.5 : In RCP 8.5 emissions continue to rise throughout the 21st century.
- In RCP 8.5, emissions continue to rise throughout the 21st century.
- It is taken as the basis for worst-case climate change scenarios.
Greenland
- It is the worlds largest Island, between Arctic and Atlantic Ocean within Denmark.
- The lowest temperature ever recorded in the Northern Hemisphere was recorded in Greenland with the Greenland Ice Sheet.
- Between 1989 and 1993, US and European climate researchers drilled into the summit of Greenland’s ice sheet.
- The glaciers of Greenland are also contributing to a rise in the global sea level faster.
- The fishing industry is the primary industry of Greenland’s economy, accounting for the majority of the country’s total exports.
Source : Down To Earth
Topic
GS III : Conservation, environmental pollution and degradation, environmental impact assessment
Current Affairs Compilation : 2 October 2020