Singapore. Environmental groups are urging Singapore to reveal details of carbon tax concessions granted to major oil companies, warning that the opaque policy could undermine efforts to transition toward cleaner energy.

The city-state, home to about 6 million people, remains the only Southeast Asian nation to impose a carbon tax. While Indonesia, Malaysia, and Thailand plan to introduce similar levies next year, and Vietnam and Brunei are considering them, Singapore’s concessions for large emitters have raised transparency concerns.

Conservationists want the government to disclose which companies have received tax “allowances” from the National Climate Change Secretariat (NCCS) and how much they have saved. The government says the discounts are not “a free pass” to pollute, but it has resisted releasing details, citing corporate confidentiality.

“Singapore is being watched and seen as a leader,” said Vinod Thomas, senior fellow at the ISEAS–Yusof Ishak Institute. “What others do will matter, because the atmosphere only cares about the total.”

Carbon Tax Policy Under Scrutiny
Singapore introduced its carbon tax in 2019, initially set at S$5 ($3.70) per ton of emissions and gradually rising to S$25 ($19) last year. The rate will increase to S$45 ($34.70) in 2026, and between S$50 and S$80 ($40–$60) by 2030.

Authorities say the gradual hike allows emissions-heavy industries time to invest in cleaner technologies. The NCCS said concessions are granted only to facilities with credible net-zero transition plans and are meant to prevent “carbon leakage,” when companies relocate to countries with looser climate rules.

However, the NCCS has not disclosed how much the carbon tax has reduced emissions, saying it is “difficult to isolate” its impact. Local groups argue this secrecy prevents the public from assessing whether the policy is working.

“We can’t even conclude if the carbon tax is effective because we don’t have the data,” said Rachel Cheang, co-founder of Energy CoLab, a youth-led climate group.

Oil Majors Among Top Emitters
The tax affects around 70 percent of Singapore’s emissions, falling heavily on global energy giants such as ExxonMobil, which operates the country’s largest refinery on Jurong Island; Shell, which runs the oldest refinery on Pulau Bukom; and Chevron, which owns half of the Singapore Refining Company.

None of the companies provided comment on the issue. Environmental group LepakInSG said disclosing corporate emission data would improve accountability.

“Such information would help the public hold them responsible,” said co-founder Ho Xiang Tian.

Households may also feel the impact. LepakInSG estimated that a S$50 carbon tax could add about S$8 ($6.20) per month to the electricity bill of a typical four-room public apartment. Ho said this increase is manageable but called for safeguards to protect low-income families.

Global Context
The call for transparency comes as international climate policy faces headwinds. Earlier this month, US President Donald Trump derailed a global effort to introduce the world’s first carbon tax on shipping emissions.

“As long as the US remains committed to fossil fuels, there’s going to be a big block on global carbon taxes,” said Shi-Ling Hsu, professor at Florida State University and author of The Case for a Carbon Tax.

Cheang said that makes Singapore’s example even more important. “We have a responsibility to uphold integrity in how we design and implement climate policies,” she said.