We ……… Are ……… F%$#ed

The Gulf Stream has slowed down by 4% over the past 4 decades with a 99% certainty.

That is a 25th of total flow, not a minuscule amount.

The Gulf Stream transport of water through the Florida Straits has slowed by 4% over the past four decades, with 99% certainty that this weakening is more than expected from random chance, according to a new study.

The Gulf Stream—which is a major ocean current off the U.S. East Coast and a part of the North Atlantic Ocean circulation—plays an important role in weather and climate, and a weakening could have significant implications.

"We conclude with a high degree of confidence that Gulf Stream transport has indeed slowed by about 4% in the past 40 years, the first conclusive, unambiguous observational evidence that this ocean current has undergone significant change in the recent past," states the journal article, "Robust weakening of the Gulf Stream during the past four decades observed in the Florida Straits," published in Geophysical Research Letters.

The from the article abstract:

We find with virtual certainty (probability P > 99%) that Gulf Stream volume transport through the Florida Straits declined by 1.2 ± 1.0 Sv [Sv stands for Sverdrup, 1 million m3/second] in the past 40 years (95% credible interval). This significant trend has emerged from the data set only over the past ten years, the first unequivocal evidence for a recent multidecadal decline in this climate-relevant component of ocean circulation.

Even assuming the low end, and assuming a 2°C temperature drop (my WAG, probably low) and a 0.2 Sv flow, the energy contained is 200,000,000 kg/second of water x 2°C x 4182 J/kg°C. = 1,672,800,000,000 J/s or 1,672,800 MW of heat not heading north.

By comparison, the US generated 4,243 terawatt-hours of electricity in 2022, and 8760 hours in a year, so the average power output of the United States is 484,361 MW, so the heat not being carried is almost 4 times that of total US power generation.

That is a f%$# tonne of heat, and that is still likely a gross understatement of the ΔQ.