PBS Terra explains 'This Is How the World Ends According to Science'

I promised a more involved post yesterday and Weathered on PBS Terra helped deliver it by explaining This Is How the World Ends According to Science.

There’s an 18% chance that global warming exceeds four degrees by 2100 and that’s not a small risk when the stakes are civilization-ending.

In this episode of Weathered, host Maiya May talks with civilization collapse researcher Luke Kemp and strategic climate risk expert Laurie Laybourn about why high-end warming scenarios are often dismissed as “doomerism,” even though worst-case planning is standard in most fields. We break down how uncertainty in climate sensitivity and political derailment could push warming higher than expected and how climate shocks can trigger cascading failures across food systems, financial markets, and geopolitics. Understanding the climate endgame isn’t pessimism. It’s risk management.

Before I address the science, I'm making a meta comment about what I've seen on PBS YouTube channels and PBS and NPR websites since the Corporation for Public Broadcasting was defunded; public media has become more opposed, even antagnostic, to Donald "Hoover Harding Cleveland" Trump's policies since. If the authors of Project 2025 thought public media was biting the hand that fed them, they might be surprised at how much their hands are being bitten now that they're not feeding public media!

As for the science, I've mentioned multiple times that current temperatures are the same as 125,000 years ago and CO₂ levels are the same as 3.6 million years ago. That was just before the Mid-Piacenzian Warm Period or Pliocene Thermal Maximum. The worst case scenario by 2100 has temperatures reaching those of the Middle Miocene Climatic Optimum or Middle Miocene Thermal Maximum, about 15 million years ago. Here are two highlights from Wikipedia.

The Arctic was ice free and warm enough to host permanent forest cover across much of its extent. Iceland had a humid and subtropical climate...Dense, humid rainforests covered much of France, Switzerland, and northern Germany, while southern and central Spain were arid and contained open environments.

That's a very different world from today.

Speaking of today's world, the L.A. fires serve as an example where climate change is already causing disasters, which the current administration denies. Looking forward to the future, a possible collapse of the AMOC would be catastrophic and magnified by our economic system. Yikes!

All this ties into last year's most read post, 'Weathered' explains 'This Is EXACTLY How Much Poorer Climate Change Will Make Every Person on Earth'. Maiya May didn't directly address this, but maybe she'll revisit climate change's effects on individual pocketbooks in the promised part two. Stay tuned.