IPCC Report 2021: Increasing Heatwaves, Shorter Cold Seasons; Know Key Findings On Impact Of Global Warming

Rise in sea level, floods, heavy rainfall, and glacier melting are among the irreversible effects of extreme sea-level events caused by Global warming. Know about the projections on Climate change.

Representative Photo: Getty Images

New Delhi: The latest Intergovernmental Panel on Climate Change's (IPCC) report on climate change, released on Monday, has scientists warning that the extreme sea-level events which previously occurred only once in 100 years can happen every year by the end of this century.

Rise in sea level, floods, heavy rainfall, and glacier melting are among the irreversible effects of such a situation.

The IPCC's Sixth Assessment Report (AR6) 'Climate Change 2021: The Physical Science Basis' also emphasises that every region in the world is witnessing irreversible changes in climate due to human influence, news agency PTI reported.

The AR6 report is approved by 195 member governments of the IPCC through virtual sessions which were held over two weeks since July 26. It projects climate changes that will increase in all regions in the coming decades.

Climate change is already affecting every region on earth, in multiple ways. The changes we experience will increase with additional warming, said IPCC Working Group I Co-Chair Panmao Zhai.

Key Findings

Here are some of the key findings of the IPCC Working Group I report, which is the first installment of the AR6, to be completed in 2022:

• Coastal areas will see continued sea-level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas and coastal erosion with extreme sea-level events that previously occurred once in 100 years could happen every year by the end of this century.
  
  
• For 1.5 degrees Celsius of global warming, there will be increasing Heatwaves, longer warm seasons, and shorter cold seasons. At 2 degrees Celsius of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health.
  
  
• Climate change is bringing multiple different changes in different regions which will all increase with further warming. These include changes to wet and dryness, to winds, snow and ice, coastal areas, and oceans.
  For example, Climate change is affecting rainfall patterns. In high latitudes, precipitation is likely to increase, while it is projected to decrease over large parts of the subtropics. Changes to monsoon precipitation are expected, which will vary by region.

• Further warming of the earth will amplify permafrost thawing, and the loss of seasonal snow cover, melting of glaciers and ice sheets, and loss of summer Arctic Sea ice.

• Changes to the ocean, including warming, more frequent marine heatwaves, ocean acidification, and reduced oxygen levels have been clearly linked to human influence. These changes affect both ocean ecosystems and the people that rely on them, and they will continue throughout at least the rest of this century, the report stated.

• For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events, and sea-level rise in coastal cities.

What Can Be Done?

According to the report, it is still possible from a physical science point of view, to limit global warming to 1.5 degrees which means these changes could be slowed and stopped from getting worse.

If emissions globally are reduced to net-zero by 2040, there is still a two-thirds chance to reach 1.5 degrees and if we globally achieve net-zero emissions by the middle of the century, there is still a one-third chance to achieve that, said Dr Friederike Otto, Associate Director of the Environmental Change Institute at the University of Oxford and one of the authors of the IPCC report.

To limit global warming, strong, rapid and sustained reductions in CO2, methane and other greenhouse gases are necessary. This would not only reduce the consequences of climate change, but also improve air quality and have a lot of other co-benefits, Otto added.

While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilise.

As for new estimates of the chances of crossing the global warming level of 1.5 degrees Celsius in the next decades, the report finds that unless there are immediate, rapid, and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5 degrees Celsius or even 2 degrees Celsius will be beyond reach.

IPCC Working Group I Co-Chair Val rie Masson-Delmotte said that this report is a reality check: "We now have a much clearer picture of the past, present and future climate, which is essential for understanding where we are headed, what can be done, and how we can prepare".

The report instills hope that human actions still have the potential to determine the future course of climate. According to the findings, the evidence that carbon dioxide is the main driver of climate change is clear, even as other greenhouse gases and air pollutants continue to affect the climate.