Bengaluru: The Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) report was published Monday, making the most startling predictions about the havoc the ongoing global heating will wreak on our planet over the coming decades.
The AR6 is the world’s largest, most scientifically accurate, and most up-to-date report on the causes and effects of human-induced climate change on the planet.
According to the latest report, past and ongoing emissions have already ensured that the temperature rise of 1.5° Celsius cannot be avoided and the temperature threshold is likely to be breached in just 20 years even if all countries move to net zero greenhouse emissions.
UN secretary-general Antonio Guterres called the report “a code red for humanity,” and said it must “sound a death knell for coal and fossil fuels before they destroy our planet”.
The IPCC is a group put together by the United Nations, comprising over 234 scientists from 66 nations. The team of scientists worked together to evaluate over 14,000 research papers over the past five years, culminating in AR6, which is the first of a three-part report.
AR6 is the sixth IPCC report since the body was set up in 1988.
IPCC reports form the scientific basis for the United Nations Framework Convention on Climate Change (UNFCCC) international environment treaty. The previous report, AR5, was released in 2013 and formed the basis of the UNFCCC Paris Agreement of 2015.
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How is AR6 different?
The latest findings have been made after methodologies used in climate science, modelling, and risk assessment evolved over the past few years. This includes updated and improved understanding of climate processes and the latest paleoclimate evidence of climate change responses.
The report implicates humans in a 1.1°C temperature rise since pre-industrial age, and states that extreme weather events being linked to human causes has strengthened since AR5.
Because of past and present emissions, the 1.5°C rise threshold is inevitably likely to be breached by 2040 in every one of the five emission scenarios, including the one with rapid decline of carbon dioxide emissions to net zero by the year 2050 globally, it says.
The report further states that in any scenario where emissions decline slowly, the temperature rise of 2°C — the limit set by the Paris Agreement — is likely to be breached by 2060. Under the very high emission scenario with little action, temperatures are likely to rise by up to 5.7°C by the year 2100.
The report goes on to say that land will continue to warm approximately 1.5 times more than the surface of the water, and that the Arctic will warm at twice the rate of global temperature rise.
As temperatures rise, the changes in regional mean temperature, precipitation, and soil moisture will get larger and larger. Extreme weather events would increase, including heatwaves and intense rainfall. Agricultural and economic droughts are also expected to follow globally, and rare events like an ice sheet collapse are now considered to be very likely to occur.
Rain will increase in the mid to long term along the coasts of Asia.
The report also offers hopeful suggestions that immediate actions towards net zero emissions globally could lower global temperature again by 0.1°C after crossing the 1.5°C threshold, before the end of the century, but would require unprecedented action by every nation.
Current climate pledges of 195 member countries of IPCC is expected to raise temperatures by 2.7°C by the end of the century.
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What is IPCC?
The precursor to IPCC was a consortium of international scientists called the Advisory Group on Greenhouse Gases that was set up in 1985, by the United Nations Environment Programme (UNEP), the International Council for Science (ICSU), and the World Meteorological Organization (WMO).
The body was formally upgraded to the IPCC in 1988 in the face of increasingly complex and interdisciplinary climate science.
The IPCC does not conduct its own research. Instead, it relies on peer-reviewed research from across the globe, analysing all the latest available data in climate science with excruciating detail and putting together a comprehensive assessment report on the state of climate change today.
The panel consists of representatives appointed by governments as well, but the reports are considered to be neutral with respect to policy.
The reports are guided by the organisation’s governing principles to produce assessment of the risk of human-induced or anthropogenic climate change, its impacts on various parts of the Earth, and solutions or options for mitigation of worst effects.
The IPCC has three working groups, each releasing assessments to do with the physical science basis of climate change, its impacts and vulnerabilities, and mitigation respectively.
Monday’s report was released by the Working Group 1, and is titled, AR6 Climate Change 2021: The Physical Science Basis.
Working Group 2’s report titled AR6 Climate Change 2022: Impacts, Adaptation and Vulnerability will be released in February 2022, while the third part titled Mitigation of Climate Change will be released a month later.
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