The global government income from oil and gas taxation fell  to a multi-year low in 2020 of around $560 billion as production and prices  shrunk. Before COVID-19, oil and gas taxes usually exceeded the trillion-dollar  mark. The accelerating energy transition will cause this source of state income  to shrink and never again exceed or meet $1 trillion, a Rystad Energy report projected.  
This year, 2021, will be the last year global oil and gas  taxes will approach the trillion-dollar mark, reaching about $975 billion, assisted  by high oil prices, according to Rystad Energy estimates. From 2022, taxes will  be limited to the low $800 billion range, ticking up in the early 2030s to  about $900 billion before starting their final and uninterrupted decline to as  low as $580 billion in 2040 and about $350 billion in 2050.
“As the energy transition ramps up, countries highly  dependent on tax revenue from the upstream industry may have no other option  than to diversify their economy to sustain state budgets. This is clearly the  rational course for them to follow, but there are inherent challenges in the  form of insufficient economic and legal institutions, infrastructure and human  capital,” said Espen Erlingsen, head of upstream research at Rystad Energy.
The earlier the energy transition risks are realized the  better they can be addressed. Structural changes will be crucial to stabilize  petroleum-reliant economies and avoid geopolitical instability as the global  energy systems shift onto a sustainable pathway, Erlingsen added.
Using Saudi Arabia as an example, about half of the  government take is at risk towards 2050, while total tax income from oil and  gas made up 27% of the country’s GDP in 2019.
Algeria, Iraq, Kuwait, and Libya—all of which are heavily  dependent on tax revenue from the upstream industry—garnered around 40% of GDP  in 2019 from oil and gas tax revenue. In these countries, about 50% of the  government take is at risk, meaning that this group is the most exposed to  revenue risk as a result of the energy transition.
“Our data and tools allow us to quantify energy transition  risk for the oil and gas upstream sector in different low-carbon scenarios. The  above estimates are produced by Rystad Energy’s base case scenario, called the  Mean scenario. To address the possibility of some deviation we also have a  low-case and a high-case scenario.”
However, the International Energy Agency’s (IEA) Sustainable  Development Scenario (SDS) model has perhaps become the most widely used  benchmark, calling for temperature increases well below 2 degrees Celsius. According  to Rystad Energy’s analysis, if the Scenario materializes, global government  income from oil and gas taxes will be much lower than its own Mean Case, with  petrostates losing a cumulative further $4.8 trillion from today until 2050.