The news from researchers at the University of Copenhagen is grim enough. They’ve been modelling the consequences of the massive Greenland ice melts, and the model shows that the input of fresh water could shut down the AMOC. They say a tipping point is visible.
The AMOC manages heat and salinity. It moves 20 million cubic metres of water per second. It’s also a heat transporter, delivering more than 100 million gigawatts of heat, which happens to be 100 times the total energy consumption of humanity. If more fresh water enters the Atlantic, obviously it affects salinity levels. That means the basal water thermal profile has to change. It means the AMOC is out of synch because the thermal profile is changed by the added fresh water, which is much lighter than sea water.
(High school science; change the composition of a gas or a liquid and its thermal properties change accordingly. That’s the basis of global warming, and it’s been 100% right so far. It’s also why pumping billions of tons of carbon dioxide into the atmosphere is such a bad move. Predictions have if anything been behind the actual speed of change.)
Things are bad enough without the Atlantic going out of whack. The melting of the Arctic has knocked the jet streams into different circulation patterns. The jet stream was responsible for the Big Freeze earlier this month. Further disruption of the core weather drivers is likely to mean more ferocious weather, hot and cold.
This will impact the Gulf Stream, the current that keeps North America warm. The theory is that the reduction in AMOC will lead to a cooling of the North Atlantic, but testing only began in 2004, so there’s no certainty whether this is correct.
Another problem is that the AMOC may draw less CO2, and therefore less heat, from the atmosphere. That’s all-round more trouble for drought-plagued North America. The Great Plains and Midwest were on the wrong end of the last mega drought, and this could mean more of the same.
It’s not clear at what point the AMOC goes dormant. It has definitely been slowing down. If the effect hits the Gulf Stream, the result could be catastrophic.
Ahem…
Need I say that after 30+ years of constant warnings and constant inaction, this is a vindication that nobody wants. There’s nothing good about this scenario. The effect on North America alone could be devastating, let alone the rest of the world.
There was never really a climate debate. Denial is not debate; it’s delusional. There will be nothing left to argue about if the north Atlantic goes down. Fix this or take the consequences.
