The 1.5°C report was a key input used in negotiations at Katowice, Poland in 2018.
Countries relied on it to commit themselves to capping global temperature rise to 1.5°C by the end of the century.
The recent report updates scientific literature available since 2015.
2015 was when the IPCC released its comprehensive 5th Assessment Report.
The report summarises the disastrous impacts of global warming based on current projections of global greenhouse gas emissions.
What are the key highlights?
Over the 21st century, the ocean is projected to make transition to unprecedented conditions.
Increased temperatures, further ocean acidification, marine heatwaves and more frequent extreme El Nino and La Nina events are the key threats.
It is virtually certain that the global ocean has warmed unabated since 1970.
It has taken up more than 90% of the excess heat in the climate system.
Since 1993, the rate of ocean warming has more than doubled.
Marine heatwaves have very likely doubled in frequency since 1982 and are further increasing in intensity.
The Southern Ocean accounted for 35%–43% of the total heat gain in the upper 2,000 m global ocean between 1970 and 2017.
Its share increased to 45%–62% between 2005 and 2017.
Threats - Even under the most optimistic scenarios, human health, livelihoods, biodiversity and food systems face a serious threat from climate change.
Accelerated rates of loss of ice, particularly in Greenland, the Arctic and the Antarctic, will produce a destructive rise in sea levels.
Increases in tropical cyclone winds, rainfall and extreme waves, combined with relative sea level rise, will exacerbate catastrophic sea level events.
All this will deal a blow also to the health of fish stocks.
What is particularly significant for countries with a long coastline, including India, is the local sea level anomalies.
Such events that occurred once in a century may become annual events, due to the projected global mean sea level rise over the 21st century.
This is an alarming scenario for the 680 million residents of low-lying coastal areas and for those living in small islands.
Notably, population of low-lying coastal areas may go up to one billion by 2050.
A major impact is in the Hindu Kush Himalayan Regions.
Floods will become more frequent and severe in the mountainous and downstream areas of the Indus, Ganges and Brahmaputra river basins.
This would be because of an increase in extreme precipitation events.
The severity of flood events is expected to more than double towards the end of the century.
What does the report call for?
There is a yawning gap between planned emissions cuts, and what needs to be done by 2030 to contain global temperature rise at 1.5°C.
The IPCC report thus lends further urgency to the task before countries at the UN conference.
The member-nations of the UNFCCC are tasked to finalise measures under Article 6 of the Paris Agreement.
The objective is to commodify carbon emissions cuts, and to make it financially attractive to reduce emissions.
The IPCC assessment underscores the need for unprecedented and urgent action in all countries that have significant greenhouse gas emissions.
It strengthens the case for industrialised nations to provide liberal, transparent funding to developing countries under the Paris Agreement.
This would reinforce the principle of Common But Differentiated Responsibilities and Respective Capabilities.
It would also recognise that rich countries reduced the carbon space available to the poor.
Source: The Hindu
Quick Fact
Intergovernmental Panel on Climate Change
IPCC was established by the United Nations Environment Programme (UNEP) and the World Meteorological Organization (WMO) in 1988.
It is the leading international body for the assessment of climate change.
It is the apex referee for scientific evidence on the impact of global warming.
It provides a clear scientific view on the current state of knowledge in climate change and its potential environmental and socio-economic impacts.
