Re: [HPAC] Simulated Climate and Carbon Cycle Response to Arctic Ocean Albedo Modification

[John Nissen]

Thanks, Chris.

This paper shows that refreezing the Arctic would have a significant benefit both to the carbon cycle, by preventing the release of permafrost carbon, and on ocean acidification.  The other impacts are relatively small.

They don't mention radiative forcing or the permafrost methane in the abstract, but then they are just talking about carbon.  A release of methane at the gigaton level would boost global warming to such an extent that the planet could become a "hot-house Earth".  This makes talk of "delaying 4°C Arctic warming" irrelevant.   Their simulation results obviously do not take into account positive feedback and tipping points.

BTW, there are estimates that Arctic permafrost has locked up around 1700 gigatonnes of carbon, i.e. 1700 PgC.  As a proportion, the 22 PgC mentioned in the abstract seems very conservative.  

Cheers, John

On Mon, Oct 20, 2025 at 12:37 PM 'Chris Vivian' via Healthy Planet Action Coalition (HPAC) <healthy-planet-...@googlegroups.com> wrote:

All,

 

This paper is of interest - https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2025EF006212.

The abstract is:

 

Arctic Ocean albedo modification (AOAM) has been proposed as a potential means to mitigate some adverse climate impacts of amplified warming over the Arctic. Here we use an Earth system model to examine the response of physical climate and carbon cycle to a hypothetical AOAM implementation in which open seawater albedo in Arctic is set to the albedo of sea ice. Simulation results show that by the end of this century, relative to SSP5-8.5, AOAM would reduce Arctic mean warming by 1.6°C and delay the occurrence of 4°C Arctic warming by more than 20 years. Meanwhile, AOAM would prevent about 16% Arctic sea ice from melting. Although AOAM directly targets the Arctic Ocean, it has much larger impacts on the land carbon sink than that of the ocean. By 2100, AOAM would reduce 6% Arctic permafrost from thawing and prevent the release of permafrost carbon by 22 PgC compared to that of SSP5-8.5. On the other hand, AOAM would only decrease ocean carbon storage by 1 PgC. Regarding ocean acidification, AOAM would significantly postpone the onset of sea surface aragonite undersaturation over some Arctic Ocean areas by more than 10 years. Simulations show that a sudden termination of AOAM would cause rapid changes of climate and carbon cycle with a rate much larger than that under SSPs scenarios. Our study demonstrates the potential of AOAM to mitigate some impacts of Arctic warming, and illustrates modest effects of AOAM on the Arctic carbon cycle.

 

Chris.

 

--
You received this message because you are subscribed to the Google Groups "Healthy Planet Action Coalition (HPAC)" group.
To unsubscribe from this group and stop receiving emails from it, send an email to healthy-planet-action...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/healthy-planet-action-coalition/0d2a01dc41b5%24db055cc0%2491101640%24%40btinternet.com.