Potential nitrous oxide (N₂O) emission from aquaculture in Nepal

ABSTRACT

Nitrous oxide has a greenhouse potential 310 times that of carbon dioxide (CO₂) over a 100-year lifespan. N₂O has been produced in the aquaculture system via nitrification and denitrification. This study mainly concerns estimation of the annual N₂O emission from aquaculture in Nepal and potential emission by the years 2020 and 2030. Theoretically, this study estimates emission of N₂O-N from aquaculture in Nepal in 2020 and 2030 to be 1.1 × 10⁸ g N₂O-N (±5.2%) and 2.24 × 10⁸ g of N₂O-N (±2.5%) of 95% confidence limit, respectively, with the emission factor 1.69 g of N₂O-N/kg of fish. In terms of carbon dioxide equivalent (CO₂eq), these values are 5.36 × 10¹⁰ g and 1.1 × 10¹¹ g, respectively, in 2020 and 2030, which accounts for 0.57% and 0.70% of Nepal’s CO₂ emission in 2020 and in 2030, respectively. This study also briefly deals with the parameters that stimulate N₂O emission and some potential technologies likely to reduce the N₂O emission in aquaculture. Greenhouse gas emission from aquaculture should be included by all countries in their estimation of global warming and climate change matters.

KEYWORDS:

• Aquaculture
• nitrous oxide emission
• nitrification
• denitrification

Acknowledgments

I would like to thank the Department of Civil Engineering for creating an environment conducive to writing this manuscript. All the authors have been self-motivated to develop this manuscript. The first author was solely responsible for expenses while preparing this manuscript. Moreover, we would like to thank the anonymous reviewers for critical and helpful comments.

Disclosure statement

No potential conflict of interest was reported by the authors.