IPCC SIXTH ASSESSMENT REPORT

SEP 27

Mains   > Environment & Ecology   >   Global warming   >   Reports and indices

IN NEWS:

  • The first part of the Sixth Assessment Report (AR6) of the Inter-governmental Panel on Climate Change (IPCC) was released recently.

IPCC:

  • The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations.
  • It provides objective and comprehensive scientific information on anthropogenic climate change, including the natural, political, and economic impacts and risks, and possible response options.
  • It was established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP).
  • Headquartered in Geneva, Switzerland, it is comprised of 195 member states.
  • In 2007, the IPCC was awarded the Nobel Peace Prize for its efforts.

WORKING:

  • IPCC does not conduct original research nor monitor climate change, but rather undertakes a periodic, systematic review of all relevant published literature.
  • Thousands of scientists and other experts volunteer to review the data and compile key findings into "Assessment Reports" for policymakers and the general public.
  • The IPCC is divided into three Working Groups and a Task Force:
    • Working Group I deal with The Physical Science Basis of Climate Change
    • Working Group II deal with Climate Change Impacts, Adaptation and Vulnerability
    • Working Group III deal with Mitigation of Climate Change
    • Task Force on National Greenhouse Gas Inventories develop and refine a methodology for the calculation and reporting of national greenhouse gas emissions and removals.

ASSESSMENT REPORT:

  • The IPCC provides regular assessments of the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation.
  • Assessment Reports consist of contributions from each Working Group and a Synthesis Report integrating these contributions and any Special Reports prepared in that assessment cycle.
  • Since 1988, the IPCC has delivered five Assessment Reports. The Sixth Assessment Report (AR6) is expected to be finalized in 2022.
  • The Working Group I contribution to the Sixth Assessment Report, “Climate Change 2021: The Physical Science Basis” is now out. 

KEY FINDINGS OF AR6:

                             

  • On Global surface temperature:
    • Global surface temperature was 1.09C higher in the decade between 2011-2020 than between 1850-1900. The last decade was hotter than any period of time in the past 1,25,000 years.
    • Temperatures will reach 1.5C above 1850-1900 levels by 2040 under all emissions scenarios and without reaching “net-zero” CO2 emissions, the climate system will continue to warm.

                  

  • On Oceans:
    • The report finds it very likely that human influence is the main driver of sea level rise since at least 1971. It is virtually certain that global mean sea level will continue to rise through 2100.

                   

    • To date, the oceans have absorbed about 20-30% of humanity’s CO2 emissions, thereby leading to higher ocean acidification.
    • Extreme weather events in the ocean are becoming frequent and increasingly severe. Eg: Marine heatwaves, which have approximately doubled in frequency since the 1980s.
    • Oceanic circulations could be altered, thereby affecting regional climates.

                

  • On atmospheric circulation:
    • Large-scale atmospheric circulation has likely been changing in recent decades. Eg: Since the 1980s, the Hadley cell has very likely widened, and monsoon rains have likely increased.
    • Also, the rising temperatures will narrow and strengthen the ITCZ, resulting in more rainfall around its core and less towards the north and south.
  • On global precipitation:
    • The report says that the precipitation extremes will increase almost everywhere. Also, the total land area subject to increasing drought frequency and severity will expand, with tropical areas such as the Amazon and Central America becoming increasingly arid.
  • On greenhouse gases:
    • Concentrations of CO2 is the highest in at least two million years. The world has already depleted 86% of its available carbon budget.
  • On global ice cover:
    • The report predicts substantial reductions in snow cover area in the northern hemisphere. The Arctic is likely to be practically sea-ice free in September at least once before 2050. The permafrost extent and volume will shrink as the climate warms.

FINDINGS CONCERNING INDIA:

                                 

  • More heatwaves:
    • AR6 predicts that India will suffer more frequent hot extremes, such as warm days, warm nights, and heat waves in the remaining decades of the 21st century.
  • Varying Monsoon:
    • Changes in monsoon precipitation are expected, with both annual and summer monsoon precipitation projected to increase.
  • Warmer Indian Ocean:
    • The report observed that the Indian Ocean has warmed faster than the global average. In the South Asian region, marine heatwaves will continue to rise.
  • Changing Himalayas:
    • Himalayan region will experience changing snowmelt patterns and changes in snowline, which could trigger more Floods and landslides.

Further reading: Climate Change Mitigation in India

PRACTICE QUESTION:

Q. Enumerate the key findings of the IPCC Sixth Assessment report. What measures have India taken towards addressing climate change?