Currently in Philadelphia — September 28 2023: Return of the clouds

The weather, currently.

With these cold mornings and warm afternoons, I’ve been having to make some tough decisions about whether or not to wear pants to work. Yesterday was weirdly gorgeous, but things will be mostly cloudy again beginning this morning. Look out for a bit of rain this afternoon (20% after 2pm), with more likely tonight and into Friday. With a high around 67F, today will be a little hotter than yesterday, just enough to make it a shorts day for me.

— Abe Musselman

What you need to know, currently.

James Hansen, the climate scientist whose 1988 testimony to Congress first made global warming an issue of national concern, has a new warning: Global warming is accelerating.

We’ve all seen the scary charts and maps of this summer of climate extremes. According to data from the first three weeks of September, it’s on track to be the most anomalously warm month we’ve ever measured as a species.

No climate scientist can honestly say they predicted this much warming this quickly, which is why all of us have been reduced to jaw-agape tweeting and comparing notes to figure out what’s happening.

Hansen believes he has narrowed it down to a change in the reflectiveness of clouds, one of the least-known parts of the climate system. Clouds are affected by all sorts of things, including particulate matter and aerosols from the burning of fossil fuels. What’s clear is that the Earth’s Energy Imbalance (EEI) is increasing. The Earth system has little choice but to warm at a faster rate.

“We predict at least a 50 percent increase of the post-2010 global warming rate, compared to the 1970-2010 rate of 0.18°C/decade. This is a partial payment in return for the Faustian bargain that humanity made when it chose to build its economies on fossil fuel energy.”

According to Hansen’s calculations, he concludes "it is now almost certain that the 12-month running mean temperature will exceed 1.5°C by May 2024 or earlier."

We are in a climate emergency.

— Eric Holthaus

What you can do, currently.

Currently Sponsorships are short messages we co-write with you to plug your org, event, or climate-friendly business with Currently subscribers. It’s a chance to boost your visibility with Currently — one of the world’s largest daily climate newsletters — and support independent climate journalism, all at the same time. Starting at just $105.

One of my favorite organizations, Mutual Aid Disaster Relief, serves as a hub of mutual aid efforts focused on climate action in emergencies — like hurricane season. Find mutual aid network near you and join, or donate to support existing networks: