Title: Efficiency of carbon sequestration by added reactive nitrogen in ocean fertilisation

Authors: Martin W. Lawrence

Addresses: School of Geosciences, University of Sydney, Sydney, NSW 2006, Australia

Abstract: Addition of limiting nutrients to the surface waters of the deep ocean will lead to increased photosynthesis and associated biological productivity. Some of carbon taken up by phytoplankton will sink to the deep ocean, providing sequestration of carbon in the deep ocean. This paper considers nitrogen as the added nutrient and determines the losses in this sequestration process, taking into account a number of mechanisms. Other factors that impact on carbon sequestration are also taken into account, such as production of other greenhouse gases, and manufacture and distribution of nutrient. The overall efficiency of the sequestration process is found to be approximately 75%, depending on the form of the nutrient. That is, up to 75% of the carbon processed by photosynthesis (on adding nitrogen) can be sequestered. This is well in excess of sequestration estimates using iron as the added nutrient.

Keywords: ocean fertilisation; carbon sequestration; nitrogen; global warming; added nutrients; surface waters; deep ocean; photosynthesis; biological productivity; greenhouse gases; GHG.

DOI: 10.1504/IJGW.2014.058754

International Journal of Global Warming, 2014 Vol.6 No.1, pp.15 - 33

Received: 11 Aug 2012
Accepted: 03 Mar 2013
Published online: 02 Jul 2014 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article