It confirms that humans have irreversibly altered the planet and locked in many changes, and the opportunity to reverse course, while very slim, is scientifically still possible if urgent and strong action to reduce carbon dioxide emissions and protect and restore nature is taken immediately.

The report by the Working Group I of the UN’s Intergovernmental Panel on Climate Change (IPCC), Climate Change 2021: The Physical Science, provides the most up-to-date understanding of the physical climate system, bringing together the latest advances in climate science. It is the first of four contributions to the IPCC’s Sixth Assessment Report (AR6).

The report brings together multiple lines of evidence showing that the window of opportunity to limit global temperature rise to 1.5°C above pre-industrial levels - the most ambitious target of  the Paris Agreement - is rapidly closing.

With global warming reaching 1.1°C, the world is already seeing devastating consequences of delayed climate action clearer than ever: from wildfires in Turkey to floods in Europe and China, heatwaves in North America to devastating drought in Madagascar. Advances in science now make it possible to directly link the increased frequency and intensity of extreme weather events to climate change.

Dr Stephen Cornelius, Chief Adviser: Climate Change and WWF global lead on the IPCC said, “This is a stark assessment of the frightening future that awaits us if we fail to act. With the world on the brink of irreversible harm, every fraction of a degree of warming matters to limit the dangers of climate change. It is clear that keeping global warming to 1.5°C is hugely challenging and can only be done if urgent action is taken globally to reduce greenhouse gas emissions and protect and restore nature.

“The UK government, as host of the most important climate conference since the Paris Agreement in 2015, must step up its efforts and show climate leadership. This must start at home, with a credible strategy to deliver the promised net-zero emissions and a fiscal test to ensure all government spending is compatible with climate targets. We won’t forget the promises that have been made, nor will future generations.” 

Manuel Pulgar-Vidal, WWF Global Climate & Energy Lead, said. “The report is an important moment in the lead-up to COP26 because it is all about certainty - certainty of the scale of the climate crisis and humankind’s role in driving extreme weather events, certainty of how much we have changed the planet, and certainty that things will continue to get worse unless we immediately change course.

“That’s why world leaders must use every opportunity, especially the upcoming G20 Summit and COP26, to deliver climate action that responds to the ambition needed to ensure the 1.5˚C goal of the Paris Agreement does not slip out of reach. 

“Agreement by leaders on a pathway for international cooperation and implementation, that is just and fair to developing countries, will be crucial. We cannot afford the future of billions of people to be hijacked by stubborn self-interest. Leaders must heed the science because we are fast running out of time.”

Rebecca Shaw, WWF Chief Scientist, said: “ This report is truly a game changer because it allows scientists to pinpoint humankind’s role in driving extreme weather events with more accuracy and certainty than ever before. It is clear that fires, floods, storms and heat waves are more extreme due to climate change.

“Scientists are certain that emissions from human activity have caused dangerous and permanent damage to the planet. Our window to reduce emissions and limit temperatures to 1.5°C is still possible, but it’s closing rapidly.

“Conserving and restoring nature is a powerful tool to remove carbon from our atmosphere, but it is not enough unless we also dramatically reduce our emissions.”

Notes for Editors:
The IPCC is the UN body for assessing the science related to climate change.

The IPCC publishes comprehensive scientific Assessment Reports every 6 to 7 years. These reports are an authoritative source of information on climate change, and underpin the international community’s understanding of climate change and related issues. The last assessment, the Fifth Assessment Report, was completed in 2013-2014 and provided the main scientific input to the Paris Agreement.

This Working Group I report - Climate Change 2021: The Physical Science, is the first of four contributions to the Sixth Assessment Report. The others are  Working Group III (Mitigation of Climate Change), Working Group II (Impacts, Adaptation and Vulnerability), and the Synthesis Report (integrates the findings of the three Working Groups) - all of which will be up for approval in 2022. 

For more information, contact: Mandy Jean Woods - mwoods@wwfint.org