PInc-PanTher estimates of Arctic permafrost soil carbon under the GeoMIP G6solar and G6sulfur experiments
<p>Circum-Arctic permafrost stores large amounts of frozen carbon that must be maintained to avoid catastrophic climate change. Solar geoengineering has the potential to cool the Arctic surface by increasing planetary albedo but could also reduce tundra productivity. Here, we improve the data-...
Main Authors: | , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2023-01-01
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Series: | Earth System Dynamics |
Online Access: | https://esd.copernicus.org/articles/14/39/2023/esd-14-39-2023.pdf |
Summary: | <p>Circum-Arctic permafrost stores large amounts of frozen carbon that must be maintained to avoid catastrophic climate change. Solar geoengineering
has the potential to cool the Arctic surface by increasing planetary albedo but could also reduce tundra productivity. Here, we improve the
data-constrained PInc-PanTher model of permafrost carbon storage by including estimates of plant productivity and rhizosphere priming on soil
carbon. Six earth system models are used to drive the model, running G6solar (solar dimming) and G6sulfur (stratospheric sulfate aerosols)
experiments, which reduce radiative forcing from SSP5-8.5 (no mitigation) to SSP2-4.5 (substantive mitigation) levels. By 2100, simulations indicate
a loss of 9.2 <span class="inline-formula">±</span> 0.4 <span class="inline-formula">million km<sup>2</sup></span> (mean <span class="inline-formula">±</span> standard error) of permafrost area and 81 <span class="inline-formula">±</span> 8 <span class="inline-formula">Pg</span> of soil carbon under the
SSP5-8.5 scenario. In comparison, under SSP2-4.5, G6solar, and G6sulfur, permafrost area loss would be mitigated by approximately 39 %, 37 %,
and 34 % and soil carbon loss by 42 %, 54 %, and 47 %, respectively, relative to SSP5-8.5. Uncertainties in permafrost soil
<span class="inline-formula">C</span> loss estimates arise mainly from changes in vegetation productivity. Increased carbon flux from vegetation to soil raises soil
<span class="inline-formula">C</span> storage, while the priming effects of root exudates lowers it, with a net mitigating effect on soil <span class="inline-formula">C</span> loss. Despite model
differences, the protective effects of G6solar and G6sulfur on permafrost area and soil <span class="inline-formula">C</span> storage are consistent and significant for all
ESMs. G6 experiments mitigate <span class="inline-formula">∼</span> <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M11" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">1</mn><mo>/</mo><mn mathvariant="normal">3</mn></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="20pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="24cd820928a87a23fd3890478006b780"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="esd-14-39-2023-ie00001.svg" width="20pt" height="14pt" src="esd-14-39-2023-ie00001.png"/></svg:svg></span></span> of permafrost area loss and halve carbon loss for SSP5-8.5, averting USD 0–70 trillion (mean of USD 20 trillion) in
economic losses through reduced permafrost emissions.</p> |
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ISSN: | 2190-4979 2190-4987 |