In a new report released on Monday, the Intergovernmental Panel on Climate Change (IPCC) warns that unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach.
The IPCC was established in 1988 by the United Nations Environment Programme and the World Meteorological Organization (WMO) to provide policymakers with regular scientific assessments on climate change, its implications and potential future risks, as well as to put forward adaptation and mitigation options.
The report, labelled Climate Change 2021: the Physical Science Basis, is a contribution to the IPCC’s Sixth Assessment Report and addresses the most updated physical understanding of the climate system and climate change, bringing together the latest advances in climate science. At the press conference on Monday, IPCC described the report as the most important report ever published.
It was approved last Friday by the 195 member governments of the IPCC, through a virtual approval session – the first in IPCCs history - that was held over two weeks starting on July 26. The whole approval process finished in time and was described as a success by IPCC. “We are making history,” the chair of the secretariat said.
In the past, the world listened but did not seem to hear the message and acted hesitantly, IPCC says, and hopes that this time a report will make a difference, especially in view of the many extreme weather events that have occurred this year. The recent changes in the climate are widespread, rapid and unprecedented in history.
The concentration of carbon dioxide in the atmosphere is the highest in at least 2 million years. Sea levels have risen at a faster rate than ever in the last 3,000 years. Extreme heat, heavy rainfall and wildfires have become more frequent and intense. Droughts are increasing in some regions. Arctic ice has decreased by 40% since 1979.
Today, about 56% of the CO2 emissions are stored in the oceans and on land (carbon sinks) but this percentage will decrease if more CO2 is emitted.
Some of these changes are irreversible but some can be slowed down or even stopped if greenhouse gas (GHG) emissions are reduced. “We must treat climate change as an immediate threat. Our generation can make things right.” There is no doubt in the report that human influence is the main driver of climate change.
The report is the outcome of a collective and collaborative effort involving reviews of 14,000 scientific studies and the contributions of 234 authors from 65 countries, the majority of which participated for the first time in IPCC’s work. A main innovative feature in the report is an interactive atlas. One third of the report focuses on the regional impact of climate change.
In a policy statement, UN Secretary-General António Guterres described the report as a “code red for humanity”.
“The alarm bells are deafening, and the evidence is irrefutable: greenhouse gas emissions from fossil fuel burning and deforestation are choking our planet and putting billions of people at immediate risk. Global heating is affecting every region on Earth, with many of the changes becoming irreversible.”
He underlined that the internationally-agreed threshold of 1.5°C is “perilously close”.
“We are already at 1.2 degrees and rising. We are at imminent risk of hitting 1.5 degrees in the near future. Every fraction of a degree counts. The only way to prevent exceeding this threshold is by urgently stepping up our efforts, and pursuing the most ambitious path. We must act decisively now to keep 1.5 alive.”
The report provides new estimates of the chances of crossing the global warming level of 1.5°C in the next decades. It shows that emissions of greenhouse gases from human activities are responsible for approximately 1.1°C of warming since 1850-1900, and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5°C of warming.
However, and this is the positive message, strong and sustained reductions in emissions of carbon dioxide (CO2) and other greenhouse gases (methane, CH4) could bring about climate neutrality by 2050 and would limit climate change.
While benefits for air quality would come quickly, it could take 20-30 years to see the increase in global temperatures stop and stabilize around 1.5 – 2°C, according to the report.
“This report is a reality check,” said IPCC Working Group I Co-Chair Valerie Masson-Delmotte. “It has been clear for decades that the Earth’s climate is changing, and the role of human influence on the climate system is undisputed. 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 lockdowns during the coronavirus crisis led to reduction in emissions by a few per cent on a global scale and improved air quality in cities but only temporarily, according to IPCC.
“The solutions are clear, the UN Secretary-General said and called on all nations, especially the G20 that account for 80 % of all GHG-emissions and bear a special responsibility to join the net zero emissions coalition and reinforce their commitments with credible, concrete and enhanced Nationally Determined Contributions and policies before the conference in Glasgow.
In particular, the report must sound “a death knell” for coal and fossil fuels, before they destroy the planet. “There must be no new coal plants built after 2021. OECD countries must phase out existing coal by 2030, with all others following suit by 2040. Countries should also end all new fossil fuel exploration and production, and shift fossil fuel subsidies into renewable energy.”
The Brussels Times