Currently in the Twin Cities — July 26, 2023: Another hot afternoon

The weather, currently.

We continue to get a little lucky with storms popping on occasion along the edge of the ‘cap’ or warmest air aloft to our south and west that prevents storm development. The next chance of thunder comes Tuesday night as storms develop in the Dakotas and track east. Those should clear early Wednesday making for another hot afternoon.

Highs will be in the mid 90s Wednesday and in the upper 90s Thursday. The heat index will be right around 100°F Thursday afternoon. Another chance of isolated thunder is possible late Thursday and a better chance of spotty storms Friday as slightly cooler air moves in. Highs should be in ‘just’ the 80s this weekend.

— Sven Sundgaard

What you can do, currently.

The climate emergency doesn’t take the summer off. In fact — as we’ve been reporting — we’re heading into an El Niño that could challenge historical records and is already supercharging weather and climate impacts around the world.

When people understand the weather they are experiencing is caused by climate change it creates a more compelling call to action to do something about it.

If these emails mean something important to you — and more importantly, if the idea of being part of a community that’s building a weather service for the climate emergency means something important to you — please chip in just $5 a month to continue making this service possible.

Thank you!!

What you need to know, currently.

A new study, out Tuesday in the prestigious journal Nature Communications, has found that a key ocean current in the Atlantic is now expected to collapse by 2050, and as early as 2025.

The Atlantic Meridional Overturning Circulation (AMOC), the collapse of which was famously exaggerated in the movie The Day After Tomorrow, has collapsed many times in the past, most recently 12,000 years ago towards the end of the last ice age. Scientists think excessive meltwater coming from Greenland could be already pushing it toward another collapse, with the current now at its weakest in 1,600 years.

The most recent IPCC assessment concluded that a AMOC collapse is unlikely this century, and that global warming in excess of 8°C may be needed. A study published just seven years ago suggested just a 44% of a collapse by the year 2300, assuming Paris emissions reductions targets are met.

The new study uses a new method to estimate the effect of current and future emissions on the strength of the current and estimates a collapse by 2050, with a 95% confidence interval of 2025–2095. According to one of the researchers who helped collect some of the study’s data back in 2005, “it is mind boggling that almost 20 years later we are seriously looking at a collapse scenario in our lifetimes.”

German oceanographer Stefan Rahmstorf, whose past work has included study of the AMOC, has an extremely helpful 10 point overview of the study and how it has changed is view of what’s possible, including the possible likelihood of a near-term collapse.

The effects of a near-term collapse of the AMOC cannot be understated. The northward current provides warmth to the Gulf Stream that, if halted significantly, would sharply cool Northern Europe and worsen its shift towards drought while most of the rest of the world continues to warm. With the ocean no longer able to as effectively transfer heat between the Caribbean and Europe, Atlantic storms could greatly intensify in frequency and severity — according to research conducted by super scientist James Hansen.

Such consequences would be so dire that, according to the researchers, they should be “avoided at all costs”. In my person opinion — if there was ever a study that justifies world leaders declaring a climate emergency and winding down fossil fuels, it’s this one.

—Eric Holthaus