Assessing the biological response to changes in ocean chemistry from increased weathering

Lead Research Organisation: University of Oxford
Department Name: Earth Sciences

Abstract

er million-year timescales, weathering of silicate and carbonate rocks draws down atmospheric carbon dioxide to be stored within the oceans. This acts as a negative feedback on carbon emissions within the carbon cycle, and prevents "runaway" greenhouse climate effects.

This DPhil project has been funded as part of the NERC-led Greenhouse Gas Removal
Programme. The aim of the NERC-led programme is to establish whether natural weathering rates could be artificially accelerated to draw down atmospheric carbon dioxide on a timescale which could achieve negative emissions i.e. the intentional removal of carbon dioxide from the atmosphere. This could help mitigate the current and future impact of global warming.

However, assuming weathering rates could be artificially accelerated, storing carbon dioxide in the ocean may have significant as yet unconstrained and unquantified ramifications. Increased weathering would raise the alkalinity of the ocean. There are three main aims of this DPhil project:

1) Determine the calcification response of the main marine calcifiers (foraminifera and corals) through laboratory and field experiments. If calcification rates can keep pace with alkalinity addition, then the draw-down of atmospheric carbon dioxide could be reversed, rendering accelerated weathering an inadequate method to achieve negative emissions. Calcein and 135Ba will be used as novel tracers of new growth in calcification rate determination experiments. The results of these experiments will then be integrated into ocean circulation models.
2) Establish the response of phytoplankton groups e.g. diatoms, dinoflagellates, cyanobacteria, coccolithophores to alkalinity addition, again through laboratory and field experiments. This addresses how marine ecosystems may be altered because of raised ocean alkalinity.
3) Investigate how phytoplankton groups respond to contaminants associated with weathering of mine waste, again through laboratory and field experiments. Mining waste is a potential material which could be artificially weathered to achieve negative emissions due to its ready availability and large surface area. This material will inevitably contain heavy metals which could stimulate growth and carbon fixation in ocean biota, or act as a toxin.

The aim is to perform field experiments in controlled reef environments in both the Gulf of Eilat and the Great Barrier Reef, in collaboration with Professor Jonathan Erez at the Hebrew University of Jerusalem and Professor Ove Hoegh-Guldberg at the University of Queensland respectively.

Planned Impact

This project brings together a trans-disciplinary team to determine the efficacy of enhanced weathering and ocean alkalinity enhancement for greenhouse gas removal, as well as its technical and socio-economic feasibility, its wider governance, ethical and societal issues, and environmental impact. The project is expected to benefit a range of communities, in different ways and over different timescales:

1. Government policymakers: who are tasked to achieve the goal of keeping global temperatures to 1.5oC above preindustrial level. In support of this task, this project will provide a comprehensive assessment of the quantity of CO2 that could be removed due to enhanced weathering and ocean alkalinity enhancement, and over what timescale. The project will also provide predictions for CO2 uptake for a range of different technologies and technological approaches.

2. Industry, who are committed to reducing levels of greenhouse gas emissions and to developing techniques to manage atmospheric CO2. In this project we will work directly with the mining industry and provide a comprehensive assessment of how they could turn their 'waste' products into a commodity for CO2 reduction thereby reducing the carbon footprint of their activities. Managing levels of CO2 in this way will require industrial capabilities on a large scale that represents an opportunity to develop new income streams to the UK economy.

3. Intergovernmental Panel on Climate Change: Our research on the efficacy of enhanced weathering and ocean alkalinity enhancement is expected to feed in to the 6th IPCC Assessment Report which will have a strong focus on climate change mitigation strategies.

4. Civil Society: Global warming is a global issue that will significantly impact the lives of our children and grandchildren. Civil society is keenly interested in science that works to mitigate these impacts, but is rightly concerned that geoengineering approaches may have unintended consequences that do more harm than good. This project will undertake research to assess the potential costs and benefits of enhanced weathering and ocean alkalinity enhancement approaches. Communicating the results of this work, to both NGOs and the wider public, will be critical for driving this approach to full-scale deployment.

Publications

10 25 50

Studentship Projects

Project Reference Relationship Related To Start End Student Name
NE/P01982X/1 30/06/2017 30/03/2022
1940087 Studentship NE/P01982X/1 30/09/2017 29/09/2021 Sophie Gill
 
Description Greenhouse Gas Removal by Enhanced Weathering (GGREW) consortium 
Organisation Cardiff University
Country United Kingdom 
Sector Academic/University 
PI Contribution Quantifying the biological response of elevated alkalinity through enhanced weathering, particularly on major plankton groups in the ocean.
Collaborator Contribution - University of Southampton are characterising the chemistry of the mine waste material intended for enhanced weathering - Heriott-Watt University are focussing on the logistics and physical processes of optimising enhanced weathering - Cardiff University are also working on characterising alkaline waste material and some work on biological response of macroalgae to enhanced alkalinity.
Impact -
Start Year 2017
 
Description Greenhouse Gas Removal by Enhanced Weathering (GGREW) consortium 
Organisation Heriot-Watt University
Department School of Engineering & Physical Sciences
Country United Kingdom 
Sector Academic/University 
PI Contribution Quantifying the biological response of elevated alkalinity through enhanced weathering, particularly on major plankton groups in the ocean.
Collaborator Contribution - University of Southampton are characterising the chemistry of the mine waste material intended for enhanced weathering - Heriott-Watt University are focussing on the logistics and physical processes of optimising enhanced weathering - Cardiff University are also working on characterising alkaline waste material and some work on biological response of macroalgae to enhanced alkalinity.
Impact -
Start Year 2017
 
Description Greenhouse Gas Removal by Enhanced Weathering (GGREW) consortium 
Organisation University of Southampton
Department Ocean and Earth Science
Country United Kingdom 
Sector Academic/University 
PI Contribution Quantifying the biological response of elevated alkalinity through enhanced weathering, particularly on major plankton groups in the ocean.
Collaborator Contribution - University of Southampton are characterising the chemistry of the mine waste material intended for enhanced weathering - Heriott-Watt University are focussing on the logistics and physical processes of optimising enhanced weathering - Cardiff University are also working on characterising alkaline waste material and some work on biological response of macroalgae to enhanced alkalinity.
Impact -
Start Year 2017
 
Description Response of planktonic foraminifera to enhanced alkalinity for carbon dioxide removal. 
Organisation Interuniversity Institute for Marine Science at Eilat
Country Israel 
Sector Academic/University 
PI Contribution Conducting field and lab work in the foraminifera-specific laboratory facilities at the Inter-University Institute of Marine Sciences, and currently writing up a manuscript on the results.
Collaborator Contribution Providing the lab facilities to complete this work, and guidance on data analysis and manuscript write-up.
Impact -
Start Year 2017
 
Description I'm a scientist get me out of here 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Q&A sessions with students (primary and secondary) online throughout the month of January 2021 in the "Planet Earth Zone"
Year(s) Of Engagement Activity 2021
URL https://imascientist.org.uk/
 
Description Interview for national news 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Invited for 5-minute interview on BBC about the role of the ocean in climate change, and the role of Carbon Dioxide Removal in meeting climate targets, on the day of the "State of the Planet" speech by Antonio Gueterres, the UN secretary general.
Year(s) Of Engagement Activity 2020
 
Description LIVE with Scientists 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Q&A about CDR technologies and plankton - intended audience of people who would not necessarily normally engage with science
Year(s) Of Engagement Activity 2020
URL https://www.youtube.com/watch?v=IimXZO4ScOw
 
Description Podcast with CRC and ANEC - Carbon Matters 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Invited to take part in a podcast on carbon removal with the Applied Negative Emissions Centre (ANEC) and Carbon Removal Centre (CRC) - called Carbon Matters.
Year(s) Of Engagement Activity 2020