A highly anticipated report by the U.N.’s climate panel warns that limiting global warming to close to 1.5 degrees Celsius or even 2 degrees Celsius above pre-industrial levels “will be beyond reach” in the next two decades without immediate, rapid and large-scale reductions in greenhouse gas emissions.

To be sure, the 1.5 degrees Celsius threshold is a crucial global target because beyond this level, so-called tipping points become more likely. Tipping points refer to an irreversible change in the climate system, locking in further global heating.

U.N. 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,” Guterres said.

The Intergovernmental Panel on Climate Change’s latest findings, approved by 195 member states on Friday, deals with the physical science basis of climate change and outline how humans are altering the planet. It is the first installment of four reports released under the IPCC’s current assessment cycle, with subsequent reports scheduled to be published next year.

The first part of the IPCC’s Sixth Assessment Report provides world leaders with a gold standard summation of modern climate science ahead of U.N. climate talks, known as COP26, in early November.

Swedish climate activist Greta Thunberg said the report contained no real surprises. “We can still avoid the worst consequences, but not if we continue like today, and not without treating the crisis like a crisis.”

Climate scientists said it is “unequivocal” that human influence has warmed the global climate system, with observed changes already impacting every region on the planet.

Some of the changes researchers observed in the climate were described as “unprecedented,” while others — such as continued sea level rise — were projected to be “irreversible over hundreds to thousands of years.”

The report shows that emissions of greenhouse gases from human activities are responsible for roughly 1.1 degrees Celsius of warming since 1850-1900, and finds that averaged over the next 20 years, global temperature is expected to reach or exceed 1.5 degrees Celsius of warming.

The IPCC report makes clear that it is not just about temperature. It says climate change is bringing different changes in different regions — and all will increase with further global heating.

These changes include more intense rainfall and associated flooding, more intense drought in many regions, coastal areas to see continued sea level rise throughout the 21st century, the amplification of permafrost thawing, ocean acidification, among many others.

Policymakers are under immense pressure to deliver on promises made as part of the Paris Agreement ahead of COP26. Yet, even as global leaders publicly acknowledge the necessity of transitioning to a low-carbon society, the world’s dependency on fossil fuels is expected to get even worse.

Almost 200 countries ratified the Paris climate accord at COP21 in 2015, agreeing to limit the planet’s temperature increase to well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C.

It remains a key focus ahead of COP26, although some climate scientists now believe that hitting this latter target is already “virtually impossible.”

It has underscored the point that limiting global warming to 1.5 degrees Celsius “could go hand in hand with ensuring a more sustainable and equitable society,” with clear benefits to both humans and natural ecosystems.

However, a U.N. analysis published earlier year found that pledges made by countries around the world to curb greenhouse gas emissions were still “very far” from the profound measures required to avoid the most devastating impacts of climate breakdown….