By Evan Bush, Seattle Times

Noah Berger/Associate Press

In the Pacific Northwest, shrinking glaciers, extreme heat waves, worsening droughts and acidifying oceans are all symptoms of climate change, which is affecting every corner of the globe and intensifying as emissions rise.

That’s according to a blunt assessment of our warming world, which says that it is “unequivocal” that humans are heating up the planet and doing so at a rate not seen in at least 2,000 years.

Many of the stark takeaways in this report — the sixth time researchers have assessed the physical science of climate change for the United Nations’ Intergovernmental Panel on Climate Change — are now familiar.

But the numbers are more specific, the scientists are more confident, and the warnings are even more direct.

The last decade’s global temperatures were likely the hottest it’s been on Earth in 125,000 years. Carbon dioxide emissions were higher in 2019 than at any time in at least 2 million years, the report says.

“Climate change is really widespread and intensifying and many of the changes are unprecedented in thousands of years,” said Kyle Armour, an associate professor and climate scientist at the University of Washington, who served as a lead author on the report. Armour added that climate change was affecting every region on Earth.

“Humans are responsible for all the warming we’ve seen in the last 100 years,” he said.

Some of climate change’s impacts — such as ocean acidification and surface temperatures — could be blunted or gradually reversed if humanity removes carbon from the atmosphere, the report says, but others, such as rising sea levels, will continue for centuries even if we draw net greenhouse-gas emissions down to zero, the report says.

“There’s so much we are committing to over centuries and millenia that can’t simply be undone and that’s the grim reality,” said Kim Cobb, the director of the global change program at Georgia Tech and a lead author of the report.

The world already has warmed by more than a degree Celsius since the 19th century. In each of the emissions scenarios the scientists considered, global temperatures reached at least 1.5 degrees Celsius higher than preindustrial times, with some projections sending them far higher.

The report is broad and generalized with little analysis specifically tailored to the Pacific Northwest. Still, the report’s implications for the Pacific Northwest are myriad, and they foretell a landscape and ecology forever shifted.

Karin Bumbaco, the assistant state climatologist for Washington, said it was “sobering” to read that heat waves once expected every 50 years were projected to be 14 times more likely if the world warms by 2 degrees Celsius over preindustrial times.

At least 129 Washingtonians suffered heat-related deaths this summer, most of them in the wake of a record-breaking heat wave in late June.

“Heat is still on my mind,” said Bumbaco, who was not part of the IPCC report process.

Bumbaco noted also that the IPCC report authors — with high confidence — projected that marine heat waves, such as the 2015 “blob” that upended marine ecosystems and killed millions of marine animals, would become more frequent.