In 2023 the five largest Western oil and gas companies spent a combined total of approximately two hundred and fifty million dollars on lobbying in the United States alone. This figure, drawn from federal disclosure requirements that capture only a portion of the industry's total political expenditure, does not include campaign contributions through political action committees, expenditure on think tanks and research organisations that produce analysis favourable to the industry's positions, advertising campaigns designed to shape public opinion on energy policy, or the enormous value of the revolving door through which former regulators, legislators and senior officials move into industry positions where their relationships and institutional knowledge are commercially deployed. The total cost of the oil industry's political operations, measured across all these channels and across all the jurisdictions in which it operates, is a multiple of the disclosed lobbying figure and would constitute, if it could be fully accounted for, one of the most significant items of expenditure in the global political economy.

The purpose of this expenditure is straightforward. The oil industry operates in a regulatory environment that is deeply consequential to its profitability. Environmental regulations determine what it costs to operate legally. Tax policy determines what share of its revenues it retains. Trade policy affects the markets it can access. Energy policy determines the competitive position of fossil fuels relative to alternatives. Subsidy policy may provide it with direct financial support or withdraw it. Permitting requirements determine how quickly and at what cost it can develop new projects. Each of these policy dimensions represents a potential source of additional cost or additional profit, and the industry has concluded, correctly, that investing in the political process that determines these outcomes is one of the highest-return activities available to it.

The United States is the most important single jurisdiction for oil industry lobbying both because of the size of the American energy market and because American regulatory and foreign policy decisions have global consequences that extend far beyond the domestic industry. The American Petroleum Institute, the industry's principal trade association, has operated a sophisticated lobbying operation in Washington for over a century. Its membership includes the largest American and international oil companies, and it coordinates their advocacy positions on regulatory, tax and energy policy issues while maintaining the plausible deniability that comes from speaking as an industry body rather than as any individual company.

Individual company lobbying complements the trade association effort. ExxonMobil, Chevron, ConocoPhillips, Shell and BP each maintain substantial Washington offices staffed by former government officials, congressional staffers and regulatory agency veterans whose value lies not only in their understanding of the legislative and regulatory process but in their personal relationships with current officeholders and their staff. These relationships are the currency of Washington influence, and the oil industry has invested heavily in accumulating them over many decades.

The documented outcomes of this investment include the defeat of climate legislation on multiple occasions when it appeared to have sufficient political momentum to pass, the preservation of the percentage depletion allowance and intangible drilling cost deduction in the federal tax code despite periodic efforts to eliminate what critics describe as unjustified subsidies to a profitable industry, the relaxation of environmental impact assessment requirements for drilling on federal lands, and the repeated delays and weakening of methane emission regulations that the industry opposed on cost grounds. Whether each of these outcomes was the correct policy decision is a legitimate matter of political debate. That they reflected the industry's preferences and were achieved in part through the industry's lobbying investment is not seriously disputed.

The European Union represents a different but equally important lobbying battleground for the oil industry. European energy and climate policy has become increasingly ambitious over the past decade, with the European Green Deal, the Fit for 55 package and the REPowerEU programme collectively representing the most significant regulatory challenge to fossil fuel interests in the history of the European project. The oil industry's response has been to significantly expand its lobbying presence in Brussels, to cultivate relationships with member state governments whose economic interests are more aligned with the fossil fuel sector than those of the Commission, and to engage actively in the technical processes through which EU regulations are drafted and refined.

Transparency International and a range of civil society organisations have documented the scale of fossil fuel industry lobbying in Brussels. The number of oil and gas company representatives accredited to lobby EU institutions runs to several hundred, and the total lobbying expenditure reported to the EU's transparency register, which underestimates the true figure due to incomplete disclosure requirements, runs to tens of millions of euros per year. The industry's lobbying targets include the energy directorate, the climate directorate, the economic affairs directorate and the European Parliament's committees on environment, energy and industry, each of which plays a role in shaping the regulatory framework within which European oil companies operate.

The specific objectives of European oil industry lobbying have evolved with the policy environment. In the earlier years of EU climate policy, the industry sought to slow the pace of emissions regulation and to preserve the free allocation of emissions permits under the EU Emissions Trading System that effectively subsidised its operations. More recently, as the energy transition has gathered momentum, the focus has shifted to securing favourable treatment for natural gas as a transition fuel, opposing the acceleration of the phase-out of internal combustion engine vehicles, and shaping the definitions of sustainable activities under the EU taxonomy in ways that preserve access to green financing for fossil fuel projects.

The revolving door between the oil industry and the regulatory and legislative bodies that govern it is one of the most structurally significant features of the political landscape in which the industry operates. The movement of senior officials from government into industry positions, and of industry executives into government roles, creates a web of personal relationships, shared assumptions and mutual professional obligations that shapes regulatory outcomes in ways that formal lobbying expenditure does not fully capture.

The pattern is well documented in the United States. Senior officials from the Environmental Protection Agency, the Interior Department, the Energy Department and the relevant congressional committees regularly move into positions with oil companies, industry trade associations or lobbying firms representing the industry upon leaving government. In the opposite direction, executives and lobbyists from the oil industry have moved into senior regulatory and advisory positions in multiple administrations. The career of Andrew Wheeler, who served as administrator of the Environmental Protection Agency under President Trump after a career as a lobbyist for the coal and oil industries, is a frequently cited example, but it is representative of a pattern that crosses party lines and extends across multiple administrations.

In Europe the revolving door operates through different institutional channels but produces similar effects. Former energy commissioners, senior officials from national energy ministries and former members of the European Parliament's energy committees regularly appear in advisory or board roles at oil and gas companies, at industry associations or at consulting firms whose clients include the fossil fuel sector. The knowledge these individuals bring to their private sector roles, their understanding of how regulatory decisions are made and their personal relationships with current officials, is precisely what makes them valuable to their new employers and precisely what makes the revolving door a structural advantage for the industries that can afford to hire them.

Beyond direct lobbying and the revolving door, the oil industry has invested heavily in the production and distribution of ideas that support its commercial interests. This investment takes several forms. Funding of academic research and university energy centres creates a pipeline of analysis sympathetic to the industry's positions and relationships with academic institutions that lend credibility to those positions. Support for think tanks and policy institutes provides a platform for the publication and dissemination of arguments favourable to fossil fuels and against regulatory intervention. Sponsorship of conferences, journals and media organisations creates opportunities to shape the framing of energy policy debates in ways that favour the industry's preferred outcomes.

The most consequential documented example of this strategy is the campaign by several major oil companies, most extensively documented in the case of ExxonMobil, to fund organisations that challenged the scientific consensus on climate change during the period between the late 1980s and the 2000s. Internal documents obtained through litigation and investigative journalism established that ExxonMobil's own scientists had concluded in the 1970s and 1980s that the burning of fossil fuels was warming the planet and that this warming would have serious consequences. The company's subsequent public position, which involved funding organisations that disputed this conclusion and promoting narratives of scientific uncertainty, has been the subject of litigation in multiple American states and investigations by state attorneys general.

The broader lesson of this episode is not that the oil industry is uniquely dishonest but that any industry with sufficient financial resources and sufficient stake in the outcome of a regulatory or policy debate has both the means and the incentive to invest in shaping the intellectual environment in which that debate takes place. The oil industry has done this more systematically and with greater resources than almost any other sector, and the consequences for the pace and ambition of climate policy over the past three decades have been significant and are now becoming measurable in the physical consequences of delayed action.

The focus of most analysis of oil industry lobbying is inevitably on the United States and Europe, where disclosure requirements make the activity at least partially visible. But the political operations of the oil industry extend to every jurisdiction in which it operates, and in many producing and importing countries the mechanisms are less regulated and the consequences more direct.

In producing countries across Africa, Latin America and Asia, the relationship between oil companies and the governments that grant them exploration licences and production sharing agreements has historically been managed through a combination of formal negotiation and informal influence that extends well beyond what would be recognised as legitimate lobbying in a Western context. The Glencore bribery prosecution documented a pattern of payments to officials in the Democratic Republic of Congo, Nigeria, Equatorial Guinea, Cameroon, Ivory Coast, Brazil and Venezuela that was sustained over many years and involved multiple levels of both the company and the governments concerned. This pattern is not unique to Glencore, as investigations in multiple jurisdictions have established, but the Glencore case provided an unusually detailed public account of how it operates.

For small oil-importing states like Mauritius, the lobbying operations of the oil majors and trading houses are less directly relevant because the industry does not have the same direct commercial relationship with the government that it has in producing states. But the policy environment that oil lobbying sustains in Washington, Brussels and the multilateral institutions influences the global energy transition in ways that affect every oil-importing economy. Delayed action on climate creates longer dependency on imported oil. Weakened fuel efficiency standards maintain demand for petroleum products. Subsidies to fossil fuels in consuming countries depress the market signal that would otherwise accelerate the transition to alternatives. The political investment of the oil industry is not geographically contained. It shapes the global energy system from which no economy, however small or however distant from the centres of lobbying power, can fully insulate itself.