IPCC and the importance of its assessment report

• The Intergovernmental Panel on Climate Change (IPCC) delivered a dire assessment and warning in its latest report released recently
• It revealed what UN Secretary-General Antonio Guterres said was “a litany of broken climate promises” by governments and corporations.

About IPCC

• It is the United Nations body for assessing the science related to climate change.
• It was set up in 1988 by the World Meteorological Organisation (WMO) and the UN Environment Programme (UNEP).
• Its main activity is to prepare Assessment Reports, special reports, and methodology reports assessing the state of knowledge of climate change.
• It does not itself engage in scientific research.
• Instead, it asks scientists from around the world to go through all the relevant scientific literature related to climate change and draw up the logical conclusions.

Assessment Reports of IPCC & Significance

• These are produced every few years, and are the most comprehensive and widely accepted scientific evaluations of the state of the Earth’s climate.
• They form the basis for government policies to tackle climate change, and provide the scientific foundation for the international climate change negotiations.
• Six Assessment Reports have been published so far and the sixth report (AR6) coming in three parts

AR6

• The first part of AR6 flagged more intense and frequent heat-waves, increased incidents of extreme rainfall, a dangerous rise in sea-levels, prolonged droughts, and melting glaciers
• It said that 1.5 degrees Celsius warming was much closer than was thought earlier, and also inevitable.
• The second part warned that multiple climate change-induced disasters were likely in the next two decades even if strong action was taken to reduce the emissions of greenhouse gases.

Assessment of Previous reports

• First Assessment Report (1990): it noted that emissions resulting from human activities are substantially increasing the atmospheric concentrations of greenhouse gases.
  • Implications: This report formed the basis for the negotiation of the UN Framework Convention on Climate Change (UNFCCC) in 1992, known as the Rio Summit.
• Second Assessment Report (1995): it revised the projected rise in global temperatures to 3 degrees Celsius above pre-industrial levels by 2100, and sea-level rise to 50 cm, in light of more evidence.
  • Implications: it was the scientific underpinning for the Kyoto Protocol of 1997.
• Third Assessment Report (2001): it revised the projected rise in global temperatures to 1.4 to 5.8 degrees Celsius by 2100 compared to 1990.
• The projected rate of warming was unprecedented in the last 10,000 years, it said.
• The report predicted increased rainfall on average, and that by 2100, sea levels were likely to rise by as much as 80 cm from 1990 levels.
• It said Glaciers would retreat during the 21st century, and the frequency, intensity, and duration of extreme weather events would increase
• Fourth Assessment Report (2007): it said greenhouse gas emissions increased by 70 per cent between 1970 and 2004, and atmospheric concentrations of CO2 in 2005 (379 ppm) were the most in 650,000 years.
• In the worst-case scenario, global temperatures could rise 4.5 degrees Celsius by 2100 from pre-industrial levels, and sea levels could be 60 cm higher than 1990 levels.
  • Implications: The report won the 2007 Nobel Peace Prize for IPCC. It was the scientific input for the 2009 Copenhagen climate meeting.
• Fifth Assessment Report (2014):it said more than half the temperature rise since 1950 was attributable to human activities, and that the atmospheric concentrations of carbon dioxide, methane, and nitrous oxide were “unprecedented” in the last 800,000 years.
• The rise in global temperatures by 2100 could be as high as 4.8 degrees Celsius from pre-industrial times, and more frequent and longer heat waves were “virtually certain”.
• A “large fraction of species” faced extinction, and food security would be undermined
  • Implications: AR5 formed the scientific basis for negotiations of the Paris Agreement in 2015.

Way Forward

Climate change is described as the greatest threat to humanity because of its irreversible impacts.Given that the climate changes that have already occurred are irreversible, there is an urgent need for a substantial and rapid reduction in carbon emissions. Before COP26 in Glasgow, Scotland, all nations, particularly the G20 and other big polluters, must join the net-zero emissions alliance and reaffirm their promises through credible, tangible, and expanded Nationally Determined Contributions and policies.