UCL climate law expert shows importance of UK Government’s new test for oil and gas projects
20 June 2025
Dr Fergus Green has published a constructive proposal for assessing the 'significance' of fossil fuel extraction projects’ climate impacts in a legally appropriate manner.

Yesterday the UK Government issued new guidance to offshore oil and gas producers that requires them to account for the emissions from oil and gas projects that will occur when the fuels they produce are burned.
The guidance is important because oil and gas producers like to hide the climate impacts of using the fuels they produce, preferring to count only the emissions from extracting the oil and gas. An important UK Supreme Court ruling in June 2024 found that producers also have to account for the emissions from burning the fuels they produce (“combustion emissions”), which can be up to 20 times higher than the emissions from the extraction process. The new government guidance provides more detail about the Government’s expectations as to how producers will explain how those combustion emissions will affect the climate.
In the UK, there is a two-stage process for the full development of a new oil and gas field. Companies first receive an award of a license that gives them the right to explore for oil and gas in an area. Upon the discovery of a field, the company can then apply for a ‘development and production consent’ to begin to extract oil and gas from the field. At this second stage, producers must conduct an environmental impact assessment (EIA) of the proposed extraction project, which is made available for public comment. It is this EIA process that must now assess the effect of combustion emissions on the climate.
Specifically, the EIA process must assess the “significance” of a project’s climate impacts. The new Government guidance clarifies that the significance of the combustion emissions from the project must be understood in light of cumulative global emissions, and with reference to the goals of the Paris Agreement. Cumulative emissions, moreover, includes not only historical global emissions, but also “other existing and planned future projects, in a global context”, according to the guidance.
Research by Dr Green and two UCL colleagues, published earlier this month, shows that cumulative emissions from existing and planned fossil fuel extraction projects dwarf the remaining “carbon budget” for limiting climate warming to within the goal set by the Paris Agreement, i.e. “Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels”.
New research by Dr Green, published in working paper form today, puts those findings into the legal context of the EIA process. Dr Green, an expert in climate law and policy, proposes a method for assessing the ‘significance’ of such projects’ impacts. The method essentially involves adding the emissions (including the combustion emissions) from the proposed project to emissions from existing or planned projects globally, and compares the size of these emissions with the remaining global carbon budget (or a range thereof) consistent with the above-mentioned goal of the Paris Agreement. The method, which Dr Green advised the Government to pursue in his submission to its public consultation on the new guidelines (which closed in January 2025), is consistent with the new guidance.
Because emissions from existing and planned fossil fuel extraction projects dwarf the remaining carbon budget for limiting climate warming to within the Paris Agreement’s temperature goal, applying Dr Green’s method leads to the conclusion that the climate impact of any new oil and gas extraction projects will be highly significant. In contrast to the oft-made claim that the emissions from any single fossil fuel project are just a “drop in the bucket” of the climate problem, Dr Green argues that the more appropriate metaphor is that of an overflowing bucket: new fossil fuel projects add ‘water’ to this already overflowing bucket.
This conclusion does not necessarily mean that new oil and gas extraction projects in the UK, such as the controversial Rosebank field that lies west of the Shetland Islands, will be rejected: the Secretary of State for Energy Security and Net Zero must decide whether to agree to grant a development and production consent by weighing the environmental effects of the project against the economic and social benefits of the project. Effectively, rather, what the new guidance does is make the environmental impacts of oil and gas projects weigh much more heavily on these metaphorical scales, meaning the economic and social benefits from the project would need to be extremely high to justify agreeing to their approval. All else equal, the new guidance makes it less likely than was previously the case that fields such as Rosebank will be approved.
Dr Green said: “An important function of the EIA process is to inform the public about the environmental impacts of large projects, including new offshore oil and gas projects. What my proposed method does is show, using a simple ratio and a vivid metaphor, that new oil and gas projects add significant new emissions to a global problem that is already out of control: there are more fossil fuels being produced already than can safely be burned in line with the goals of the Paris Agreement”.
Additional material
Dr Fergus Green's academic profile
UCL Department of Political Science
UCL Social & Historical Sciences