IPCC report: Sea level rise is certain

Intergovernmental Panel on Climate Change (IPCC) recently published the Assessment Report from Working Group I titled “Climate Change 2021: The Physical Science Basis”. The report call for is a clear climate action.

Key Points

• IPCC report provides one of the most expansive scientific reviews on science and impacts of climate change.
• It discussed five different shared socio-economic pathways for future with different levels of greenhouse gas (GHG) emissions.
• It illustrated following scenarios-

1. Very low and low GHG emissions– Here, emissions decline to net zero around the middle of the century. Beyond this, emissions are net negative.
2. Intermediate GHG emissions- Emissions are double the current level by 2100.
3. High and very high emissions– Here, emissions are double the current levels by 2050.

• In the intermediate scenario, Average warming is likely to exceed 2°C near mid-century.
• Average global temperature is currently 1.09°C higher than pre-industrial levels while the CO2 concentration in the atmosphere is 410 ppm as compared to 285 ppm in 1850.

Concerns of rising sea level

• About 700 million people across the world live along the coast and the plans to expand coastal cities still continue.
• Thus, understanding of the risks involved from climate change and rising sea level is crucial in 21st and 22nd centuries.
• Sea level will continue to rise even after emissions are no longer increasing, because oceans respond slowly to warming.
• Global mean sea level (GMSL) increased by 0.2m in between 1901 and 2018.
• Average rate of sea level rise was 1.3 mm/year in between 1901-1971 and increased to 3.7 mm/year in the year 2006-2018.

How Sea level increases?

Sea level rises due to the expansion of warm ocean waters, melting of ice sheets in Greenland & Antarctica and melting of glaciers on land.

Month: Current Affairs - September, 2021