Global importance of methane emissions from drainage ditches and canals



Peacock, M ORCID: 0000-0002-3086-2854, Audet, J, Bastviken, D, Futter, MN, Gauci, V, Grinham, A, Harrison, JA, Kent, MS, Kosten, S, Lovelock, CE
et al (show 2 more authors) (2021) Global importance of methane emissions from drainage ditches and canals. ENVIRONMENTAL RESEARCH LETTERS, 16 (4). 044010-044010.

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Abstract

<jats:title>Abstract</jats:title> <jats:p>Globally, there are millions of kilometres of drainage ditches which have the potential to emit the powerful greenhouse gas methane (CH<jats:sub>4</jats:sub>), but these emissions are not reported in budgets of inland waters or drained lands. Here, we synthesise data to show that ditches spanning a global latitudinal gradient and across different land uses emit large quantities of CH<jats:sub>4</jats:sub> to the atmosphere. Area-specific emissions are comparable to those from lakes, streams, reservoirs, and wetlands. While it is generally assumed that drainage negates terrestrial CH<jats:sub>4</jats:sub> emissions, we find that CH<jats:sub>4</jats:sub> emissions from ditches can, on average, offset ∼10% of this reduction. Using global areas of drained land we show that ditches contribute 3.5 Tg CH<jats:sub>4</jats:sub> yr<jats:sup>−1</jats:sup> (0.6–10.5 Tg CH<jats:sub>4</jats:sub> yr<jats:sup>−1</jats:sup>); equivalent to 0.2%–3% of global anthropogenic CH<jats:sub>4</jats:sub> emissions. A positive relationship between CH<jats:sub>4</jats:sub> emissions and temperature was found, and emissions were highest from eutrophic ditches. We advocate the inclusion of ditch emissions in national GHG inventories, as neglecting them can lead to incorrect conclusions concerning the impact of drainage-based land management on CH<jats:sub>4</jats:sub> budgets.</jats:p>

Item Type: Article
Uncontrolled Keywords: methane, ditch, greenhouse gas, drainage, land use
Divisions: Faculty of Science and Engineering > School of Environmental Sciences
Depositing User: Symplectic Admin
Date Deposited: 01 Aug 2022 15:19
Last Modified: 18 Jan 2023 20:54
DOI: 10.1088/1748-9326/abeb36
Open Access URL: https://iopscience.iop.org/article/10.1088/1748-93...
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3160088