The United Arab Emirates, which will run the crucial Cop28 UN climate summit in December, has failed to report its emissions of the powerful greenhouse gas methane to the UN for almost a decade, the Guardian can reveal.

Its state oil company, Adnoc, whose chief executive, Sultan Al Jaber, controversially will preside over the climate summit, has also set itself a methane leak target far higher than the level it claims it has already reached. Al Jaber recently urged countries and companies to be “brutally honest” about the inadequacy of global action to fight the climate crisis.

Al Jaber is tasked with leading countries at Cop28 to deliver the climate action desperately needed, with extreme weather damaging lives across the world. He has previously been backed by the US and EU but has also faced calls to step down.

Critics say the revelations, and the UAE’s huge planned expansion of oil and gas production against scientific advice, show the “opposite of leadership” and undermine Al Jaber’s credibility.

Methane is responsible for about a quarter of global heating, and leaks from fossil fuel exploitation are a key source. Cutting these emissions is a fast and low-cost way to slow the temperature rise.

The UN’s climate body has required countries to submit their methane emissions every two years since 2014. The UAE has not submitted any reports, unlike other Middle Eastern oil states including Saudi Arabia, Kuwait and Oman.

In July, Al Jaber called on countries to update another type of submission to the UN, climate action plans called nationally determined contributions.

Cutting methane emissions from oil and gas production is seen as a vital part of climate action, and Adnoc announced in October 2022 that it would aim by 2025 to limit leaks to less than 0.15% of the gas produced.

However, the company’s estimate of its level of emissions for 2022 was 0.07%, announced after an Adnoc board meeting chaired by the UAE crown prince, Khaled bin Mohamed bin Zayed.

The 0.15% methane target is also higher than the level achieved in 2019 by Qatar (0.06%) and Saudi Arabia (0.14%), according to a recently published satellite analysis by scientists at Harvard University in the US.

The study estimated the UAE’s methane leaks in 2019 at 3.3% and said “these high values [in UAE and other nations] reflect leaky infrastructure combined with deliberate venting or incomplete flaring of gas”.

Adnoc reported its total methane emissions from upstream oil and gas operations in 2021 as being 38,000 tonnes. This represents 3% of the UAE’s total methane emissions from such operations, according to data from the International Energy Agency. This appears to contrast with data showing that Adnoc is responsible for 62% of all upstream oil and gas in the UAE.

In July, Adnoc brought forward its overall “net zero” emissions target from 2050 to 2045. However, this includes only the emissions resulting from operating its exploration and production facilities, which are called scope 1 and 2 emissions, and not the far greater scope 3 emissions resulting from the burning of the oil and gas it sells.

A recent estimate found Adnoc’s operational emissions were just 7% of the total. Ten other oil companies have made net zero pledges that include all emissions, according to the energy consultancy Wood Mackenzie. Al Jaber said in July: “We need to attack all emissions, everywhere. [Scope] 1, 2 and 3.”

Kjell Kühne, a researcher with the Leave it in the Ground Initiative, said: “The UAE wishes to lead the world on climate this year, and methane is a litmus test. Building new fossil gas projects, setting incoherent targets and failing to properly report methane emissions are three ways Abu Dhabi is showing the opposite of leadership.

“The biggest leadership failure is on scope 3 emissions. Even the best PR in the world cannot hide the fact that we will not save the climate with more fossil fuels. Actions, not words are required from an aspiring leader at this point.”

Gareth Redmond-King, at the Energy and Climate Intelligence Unit in the UK, said: “Leadership is core to the difficult and demanding job of the Cop presidency. No one expects that to mean the host country is perfect, but leadership does require some credibility both in terms of ambition and delivery.

“So Dr Al Jaber’s leadership role – urging others to go further on their ambition and delivery – is not made any easier by the UAE not even having submitted reports on their own methane emissions for nearly a decade. It certainly does nothing to disprove accusations that his role as president of Cop28 is incompatible with his role as CEO of the state oil and gas company.”

A spokesperson for Adnoc said: “Our 2022 upstream [scope 1 and 2] emissions data confirmed Adnoc as one of the least carbon-intensive producers in the world. Collaboration and innovation will be key to addressing scope 3 emissions and we are working with our customers to help them transition to new energies. In Adnoc, we aim to achieve zero methane emissions by 2030.”

The company intends to deliver well below the target of 0.15% by 2025, he said. “A world-leading methane intensity target should not be confused with the actual (lower) intensity that we aim to deliver, as we are committed to reducing [it] to the lowest possible level.”

The media office for Cop28 did not respond to a request for comment. Al Jaber, who is also the chair of the UAE renewable energy group Masdar, told the Guardian in July: “Phasing down fossil fuels is inevitable and it is essential – it’s going to happen. [But] you can’t unplug the world from the current energy system before you build the new energy system.” He did not specify a timescale for the phasing down of fossil fuels.

Masdar has hired a new PR company, Politico reported recently, whose work will include seeking “politically influential individuals” to act “as independent, third-party endorsers and supporters of the UAE, Dr Al Jaber and Cop28”.

The UAE increased the ambition of its national climate pledges recently. However, the pledge would still allow UAE’s carbon emissions to increase up to 2030, and the independent Climate Action Tracker consortium rated the UAE’s plans as “insufficient”.

The Guardian revealed in June that Adnoc had been able to read emails to and from the Cop28 climate summit office.

The Guardian also reported on an army of fake social media accounts promoting and defending the UAE’s hosting of Cop28. In May, Al Jaber was accused of attempting to “greenwash” his image after members of his team edited Wikipedia pages.

David Tong, of Oil Change International, said: “It seems unlikely that an oil executive could persuade countries to phase down oil and gas when his own company is busy scaling up oil and gas production. The best way for the UAE to confront its crisis in credibility is to ensure that Cop28 adopts a comprehensive energy transformation package – which requires a full, fast, fair, fossil fuel phase out.”