New study: AMOC, the Atlantic Meridional Overturning Circulation, could already start to collapse now (before or around 2025, 25% probability), even under current 'moderate' emission trajectories. For NW-Europe, this would mean much colder winters, stronger storms and less precipitation.
Paper here.
The news item focusses on the most probable year the collapse would begin (middle of the probability distribution), but also has the numbers for the 25th percentile; a very substantial risk. For the intermediate emission scenario (SSP2-4.5), which comes close to our current trajectory, that's 2026.
Quote from the paper: An analysis consisting of 25 different climate models shows that the AMOC could begin to collapse by 2063 (from 2026 to 2095, 25th to 57th percentiles) under an intermediate emission scenario (SSP2-4.5), or by 2055 (from 2023 to 2076, 25th to 75th percentiles) under a high-end emission scenario (SSP5-8.5). When the AMOC collapses, the Northwestern European climate changes drastically and this will likely induce severe societal impacts.
Important message: rapid global emission reduction reduces the probability of an AMOC collapse.
Because the AMOC is already slowing down, the study's main author, René van Westen of @utrechtuniversity said on Dutch TV news that winter temperatures here may already start to go down.
Prof. Caroline Katsman (TU Delft): "People sometimes joke that this will mean more ice skating. But we won't have time for that, because the entire food supply will break down."
Climate scientist Sybren Drijfhout (@unisouthampton ,
@utrechtuniversity ): "The weather will be colder, rougher, and drier here in NW-Europe. Extra sea level rise, more storm floods, 1/3 less agricultural production. For centuries."
Reminder: This bears big risks (25% is a lot) for our energy system: we may have to deal with much colder winters within the lifetime of investments in power systems, heating systems, and (insulation of) homes!
I started talking about this in the Netherlands in 2016, but it's only slowly sinking in.
Just to be sure: the 'tipping point' discussed here is the start of the collapse, which from that point in time is unavoidable, but takes a long time.
From the paper's Plain Language Summary:
"If the AMOC starts to collapse, it takes more than 100 years to reach a substantially weaker state. During that transition, the Northwestern European climate would change drastically and is expected to see colder winters, less rainfall, and more severe winter storms."
tl;dr
in reply to Ferda • • •