IPCC report forecasts a future of severe weather

Syllabus: General studies paper 3

Context:

The Indian Ocean is warming at a higher rate than other oceans, said the latest report by the Intergovernmental Panel on Climate Change (IPCC).

Key Findings of the IPCC report:

• The recently released report is the first part of the Sixth Assessment Report by IPCC.
• The scientists warned that India will witness increased heatwaves and flooding, which will be the irreversible effects of climate change.
  • The current overall global warming trends are likely to lead to an increase in annual mean precipitation over India, with more severe rain expected over southern India in the coming decades.

Increase in Sea level:

• The warming of the ocean would lead to a rise in sea levels, leading to frequent and severe coastal flooding in low-level areas.
• With a 7,517-km coastline, India would face significant threats from the rising seas.
• Across the port cities of Chennai, Kochi, Kolkata, Mumbai, Surat and Visakhapatnam, 28.6 million people would be exposed to coastal flooding if sea levels rise by 50 cm.

Extreme Monsoon:       

• Monsoon extremes are likely to increase over India and South Asia, while the frequency of short intense rainy days is expected to rise.
• Models also indicate a lengthening of the monsoon over India by the end of the 21st century, with the South Asian monsoon precipitation projected to increase.

• The probable cause cited in the report:
  • Stating that human activities are causing climate change, the report said the planet was irrevocably headed towards warming by 1.5 degrees Celsius over pre-industrial times in the next two decades.
• The increases in temperature, rainfall, or other factors like glacier melting that are reported in the assessment (report), are mainly averages.
  • But averages often mask the extremes.
  • In a 2°C warmer world, for example, not every day would be 2°C warmer than pre-industrial times.
  • Some days can be 6°C to 8°C, or even 10°C, warmer.
  • That is how global warming will manifest at the local levels

Tropical Cyclones:

• Tropical cyclones are getting stronger and wetter, while Arctic Sea ice is dwindling in the summer and permafrost is thawing.
  • All these trends will get worse.

Glaciers:

• Glaciers in the Hindu Kush Himalayan (HKH) region will keep shrinking and the snow cover will retreat to higher altitudes.
• It is projected to increase in major mountainous regions with potential cascading consequences of floods, landslides and lake outbursts in all scenarios.
• The snow cover had reduced since the early 21st century and glaciers had thinned, retreated and lost mass since the 1970s.
  • However, the Karakoram glaciers had either slightly gained mass or were in an approximately balanced state.
• Snow-covered areas and snow volumes will decrease during the 21st century, snowline elevations will rise and glacier mass is likely to decline with greater mass loss in higher greenhouse gas emission scenarios.
• Rising temperatures and precipitation can increase the occurrence of glacial lake outburst floods and landslides over moraine-dammed lakes.

Permafrost thaw:

• According to the report, mountain glaciers will continue to shrink and permafrost to thaw in all regions where they are present.
• The human influence was responsible for the retreat of glaciers since the 20th century and that was not only the case in the two poles, but also for mountain glaciers.

• Glacial lake bursts,a familiar occurrence in the Himalayan region, is also an example of a compound event, accompanied as it is with heavy rainfall and flooding.
  • Compound events can be several times deadlier.
  • If occurring together, they feed into each other, aggravating each other’s impacts.
  • If occurring one after the other, they give little time for communities to recover, thus making them much more vulnerable.
• Report Recommendations:
  • The countries strive to achieve net-zero emissions — no additional greenhouse gases are emitted — by 2050.
  • In the most ambitious emissions pathway, the projection is that the globe would reach the 1.5 degrees Celsius scenario in the 2030s, overshoot to 1.6 degrees Celsius, with temperatures dropping back down to 1.4 degrees Celsius at the end of the century.
    • India has not yet committed to a net-zero timeline.

Way forward:

• This moment requires world leaders, the private sector and individuals to act together with urgency and do everything it takes to protect our planet.
• The IPCC report will be a wake-up call for the world to take action now before we meet in Glasgow in November for the critical COP26 summit.
• Immediate emission cuts and a steady pathway to net-zero is expected to bring better benefits than a business-as-usual scenario and a sudden drop in emissions towards the end to meet the target.
• All nations that have not yet done so still have the opportunity to submit ambitious NDCs.
• Nations that have already submitted new or updated NDCs still have the opportunity to review and enhance their level of ambition.

The Indian Express:

https://indianexpress.com/article/explained/explained-ipcc-assessment-reports-understanding-climate-change-7445587/