Research and analysis

A scoping review of monitoring capabilities for Net Zero technologies: summary

Published 17 September 2026

Applies to England

1. Chief Scientist’s Group report summary

This study provides a high‑level scoping assessment of pollutant monitoring requirements associated with net zero technologies likely to be deployed in England over the next decade.

1.1 Background

The UK government has committed to reducing greenhouse gas emissions by 100%, against a 1990 baseline, by 2050. It means the UK will balance the amount of greenhouse gases it puts into the atmosphere with an equal amount removed. This is known as net zero. A net zero pathway is a step-by-step plan for achieving this goal by reducing emissions over time. Achieving net zero though all likely pathways requires the deployment of a range of new technologies, such as carbon capture and storage. Many of these technologies have the potential to emit pollutants. To effectively assess and manage any environmental or human health risks associated with these pollutants, it is necessary to monitor them.

1.2 Approach

The study undertook a rapid review of publicly available literature on net zero technologies, relevant regulatory guidance, and expert opinion from a project steering group. It aims to identify potential new or poorly characterised pollutants, assess the availability and maturity of monitoring methods, and highlight gaps to inform future regulation.

67 net zero technologies and activities were screened using criteria including commercial readiness, permitting likelihood and pollutant generation. These technologies primarily related to carbon capture (including solvent‑based, solid sorbent and novel approaches), thermal energy storage (mine water, aquifer/borehole and molten silicon), and carbon sequestration (biochar).

1.3 Results

The screening assessment produced a shortlist of 13 priority technologies and 2 cross‑technology pollutants (ammonia and hydrogen) which span multiple net zero pathways. 53 potential pollutants were identified, covering air, water and land pathways. Substances of concern include amines, nitrosamines and nitramines, fugitive ammonia, ambient hydrogen, N‑methyl‑2‑pyrrolidone (NMP), phenoxide salts, environmentally persistent free radicals, radon and radium, saline intrusion, and thermal plumes. Reviewing against existing Environment Agency monitoring guidance showed that established methods were available for some pollutants (for example, radon, radium, thermal plumes, NMP and ammonia in ambient air), while others had methods that are technically feasible but are insufficiently validated for regulatory application. 

The study highlighted important uncertainties and evidence gaps, notably the current lack of data on expected emission concentrations for emerging technologies, limited validation of methods across environmental media, and several pollutant classes that are poorly defined (for example, nanobiochar and some degradation products). No nationwide monitoring programmes currently cover all the emerging pollutants identified.

1.4 Conclusions

While monitoring is feasible for many net zero‑related pollutants, the study highlighted important uncertainties and evidence gaps such as characterising emissions, validating and standardising monitoring techniques, and supporting robust permitting and compliance for future net zero deployments. 

1.5 Publication details

This summary relates to information from project SC250028, reported in detail in the following output:

• Report: SC250028/R1
• Title: A scoping review of monitoring capabilities for Net Zero technologies
• Science Manager: Bob Barnes, Chief Scientist’s Group
• Research Contractor: WSP UK Ltd

This project was commissioned by the Environment Agency’s Chief Scientist’s Group, which provides scientific knowledge, tools and techniques to enable us to protect and manage the environment as effectively as possible.

Enquiries: research@environment-agency.gov.uk.

© Environment Agency