Methane emissions from Arctic landscapes during 2000–2015: an analysis with land and lake biogeochemistry models
<p>Wetlands and freshwater bodies (mainly lakes) are the largest natural sources of the greenhouse gas CH<span class="inline-formula"><sub>4</sub></span> to the atmosphere. Great efforts have been made to quantify these source emissions and their uncertainties...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-03-01
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| Series: | Biogeosciences |
| Online Access: | https://bg.copernicus.org/articles/20/1181/2023/bg-20-1181-2023.pdf |
| Summary: | <p>Wetlands and freshwater bodies (mainly lakes) are the largest
natural sources of the greenhouse gas CH<span class="inline-formula"><sub>4</sub></span> to the atmosphere. Great efforts
have been made to quantify these source emissions and their uncertainties.
Previous research suggests that there might be significant uncertainties
coming from “double accounting” emissions from freshwater bodies and
wetlands. Here we quantify the methane emissions from both land and
freshwater bodies in the pan-Arctic with two process-based biogeochemistry
models by minimizing the double accounting at the landscape scale. Two
non-overlapping dynamic areal change datasets are used to drive the models.
We estimate that the total methane emissions from the pan-Arctic are 36.46 <span class="inline-formula">±</span> 1.02 Tg CH<span class="inline-formula"><sub>4</sub></span> yr<span class="inline-formula"><sup>−1</sup></span> during 2000–2015, of which wetlands and
freshwater bodies are 21.69 <span class="inline-formula">±</span> 0.59 Tg CH<span class="inline-formula"><sub>4</sub></span> yr<span class="inline-formula"><sup>−1</sup></span> and 14.76 <span class="inline-formula">±</span> 0.44 Tg CH<span class="inline-formula"><sub>4</sub></span> yr<span class="inline-formula"><sup>−1</sup></span>, respectively. Our estimation narrows the
difference between previous bottom-up (53.9 Tg CH<span class="inline-formula"><sub>4</sub></span> yr<span class="inline-formula"><sup>−1</sup></span>) and
top-down (29 Tg CH<span class="inline-formula"><sub>4</sub></span> yr<span class="inline-formula"><sup>−1</sup></span>) estimates. Our correlation analysis
shows that air temperature is the most important driver for methane emissions
of inland water systems. Wetland emissions are also significantly affected by
vapor pressure, while lake emissions are more influenced by precipitation and
landscape areal changes. Sensitivity tests indicate that pan-Arctic lake
CH<span class="inline-formula"><sub>4</sub></span> emissions were highly influenced by air temperature but less by
lake sediment carbon increase.</p> |
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| ISSN: | 1726-4170 1726-4189 |