Simulated Climate and Carbon Cycle Response to Arctic Ocean Albedo Modification

[Geoengineering News]

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2025EF006212

Authors: Jiu Jiang, Long Cao, Han Zhang

First published: 16 October 2025

https://doi.org/10.1029/2025EF006212

Abstract

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.

Plain Language Summary

Arctic warming is accelerating partly because melting sea ice exposes darker ocean surface, and absorbs more solar radiation. Increasing the Arctic Ocean surface albedo to reflect more incoming sunlight has been proposed as a potential means to counteract the accelerated Arctic warming. Here we analyze how the increase in Arctic Ocean surface albedo could affect Arctic climate and carbon cycle under high atmospheric CO2 emission scenarios. Our analysis shows that the ocean surface albedo enhancement over the Arctic can help slow down Arctic temperature increase and reduce sea ice loss induced by global warming. It would also help preserve Arctic permafrost, suppressing carbon release from thawing soil. In addition, ocean albedo enhancement would delay ocean acidification in parts of the Arctic Ocean, potentially allowing marine ecosystems more time to adapt. However, a sudden termination of such albedo modification could cause rapid climate change that are much faster than those caused by high CO2 emissions.

Key Points

We examine climate and carbon cycle response to Arctic Ocean albedo modification (AOAM)

AOAM would help to delay Arctic warming and prevent part of sea ice loss

AOAM would prevent a fraction of permafrost from thawing and suppress loss of permafrost carbon

Source: AGU