The latest Intergovernmental Panel on Climate Change (IPCC) Report provides new estimates of the chances of crossing the global warming level of 1.5°C in the next decades and finds that unless there are immediate, rapid and large-scale reductions in greenhouse gas (GHG) emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach.
“Today’s IPCC Working Group 1 Report is a code red for humanity,” warned UN Secretary-General, António Guterres. “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,” said the Secretary-General adding that global heating is affecting every region on Earth, with many of the changes becoming irreversible.
The IPCC report confirms that it is indisputable that human influence has warmed the climate system. The report also shows that global surface temperature will continue to increase until at least the mid-century under all emissions scenarios considered and global warming of 1.5°C and 2°C will be exceeded during the 21st century unless deep reductions in carbon dioxide (CO2) and other greenhouse gas emissions occur in the coming decades.
Every region face increasing changes
“Climate change is already affecting every region on Earth, in multiple ways,” said IPCC Working Group I Co-Chair Panmao Zhai, adding that the changes we experience will increase with additional warming.
The report projects that in the coming decades climate changes will increase in all regions. For 1.5°C of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health, the report shows.
But it is not just about temperature. Climate change is bringing multiple different changes in different regions – which will all increase with further warming. These include changes to wetness and dryness, to winds, snow and ice, coastal areas and oceans.
For instance, climate change is intensifying the water cycle, bringing more intense rainfall and associated flooding, as well as more intense drought in many regions.
Coastal areas will see continued sea-level rise throughout the 21st century, contributing to more frequent and severe coastal flooding in low-lying areas and coastal erosion. Extreme sea-level events that previously occurred once in 100 years could happen every year by the end of this century.
Changes to the ocean, including warming, more frequent marine heatwaves, ocean acidification, and reduced oxygen levels have been clearly linked to human influence. These changes affect both ocean ecosystems and the people that rely on them, and they will continue throughout at least the rest of this century.
For cities, some aspects of climate change may be amplified, including heat (since urban areas are usually warmer than their surroundings), flooding from heavy precipitation events and sea-level rise in coastal cities.
Human-induced climate change is already affecting many weather and climate extremes in every region across the globe. Evidence of observed changes in extremes such as heatwaves, heavy precipitation, droughts, and tropical cyclones, and, in particular, their attribution to human influence, has strengthened since the IPCC’s last report.
A wake-up call for urgent action
“This report is a reality check,” said IPCC Working Group I Co-Chair Valérie Masson-Delmotte. “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.”
Many of the changes observed in the climate are unprecedented in thousands, if not hundreds of thousands of years, and some of the changes already set in motion—such as continued sea-level rise—are irreversible over hundreds to thousands of years. However, strong and sustained reductions in emissions of CO2 and other greenhouse gases would limit climate change. While benefits for air quality would come quickly, it could take 20-30 years to see global temperatures stabilize.
The report also shows that human actions still have the potential to determine the future course of climate. The evidence is clear that CO2 is the main driver of climate change, even as other greenhouse gases and air pollutants also affect the climate.
“Stabilising the climate will require strong, rapid, and sustained reductions in greenhouse gas emissions, and reaching net-zero CO2 emissions,” underlined Panmao Zhai.
The IPCC has produced climate reports for over 30 years and the warnings have been more alarming each time. 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. Yet the new report also reflects major advances in the science of attribution – understanding the role of climate change in intensifying specific weather and climate events such as extreme heat waves and heavy rainfall events.
“This report reflects extraordinary efforts under exceptional circumstances,” said Panmao Zhai. “The innovations in this report, and advances in climate science that it reflects, provide an invaluable input into climate negotiations and decision-making.”
For the first time, the report provides a more detailed regional assessment of climate change, including a focus on useful information that can inform risk assessment, adaptation, and other decision-making, and a new framework that helps translate physical changes in the climate – heat, cold, rain, drought, snow, wind, coastal flooding and more – into what they mean for society and ecosystems.
Sound policy and action must follow suit
Ahead of COP26 this November, UN Climate Change (UNFCCC) hopes that the IPCC’s report will encourage countries to rise to the challenge of increasing ambition and increase their climate goals as the only way forward.
2021 marks a crucial year as nations submit their new or updated Nationally Determined Contributions (NDCs), embodying the efforts and actions of each country to respond to climate change and reduce emissions.
An initial synthesis of submitted new or updated NDCs early in 2021 showed that collective efforts fall far short of what is required by science to limit global temperature increases by the end of the century to 2°C, let alone the desired objective of less than 1.5°C.
The IPCC’s Summary for Policy Makers underscores, limiting warming to 1.5°C can only be achieved through immediate and significantly scaled-up reductions. The only way to reach this goal is through the rapid implementation of more ambitious NDCs.
However, at present, only slightly more than half of all Parties to the Paris Agreement have submitted new or updated NDCs.
The UNFCCC warned that pursuing efforts towards 1.5ºC through the implementation of ambitious NDCs is essential for our future and for future generations’ well-being.