MOSCOW (BLOOMBERG) - Russia is finally engaging with the global effort to fight climate change after years of denial.

That is an important step from one of the world's largest fossil-fuel producers, but the Kremlin's green conversion may complicate negotiations at next week's COP26 summit and beyond.

Officials from President Vladimir Putin down say they are seeking changes to what they describe as radical climate dogma that would unlock real-world cuts to harmful greenhouse gases, while avoiding energy supply crises of the kind currently shaking natural gas markets.

However sincere Russia's engagement turns out to be, some of its initiatives are stirring unease over a lack of detail.

Others, such as exempting green investments from economic sanctions and swiftly opening the politically controversial Nord Stream 2 natural gas pipeline between Russia and Germany, risk dragging wider geopolitical disputes into climate negotiations.

The kind of grand bargain those proposals require would be all but impossible to achieve, given the standoff between Russia and the West over Ukraine since the 2014 annexation of Crimea, according to one climate diplomat from a Group of 20 (G-20) nation, who asked not to be named as he was not authorised to speak with media.

"Something needs to be done," Mr Putin told the annual Valdai Discussion Club meeting of foreign policy experts on Oct 21 in Russia's Sochi, where he acknowledged the climate challenge.

Although he has opted not to travel to the COP26 talks in Glasgow, the Kremlin now sees climate issues as among the few areas of possible cooperation with the United States and Europe after years of worsening relations.

Yet Mr Putin also made clear that Russia would move cautiously, citing its brutal experience with Bolshevik radicalism in the 20th century.

"No revolution was worth the damage it did to the human potential," he said.

Among climate diplomats canvassed ahead of the summit, there is broad scepticism about the change of heart, despite Mr Putin's commitment this month to cut Russia's net carbon dioxide (CO2) emissions to zero by 2060.

Although most said they believed his interest is genuine, they questioned the credibility or feasibility of some Russian proposals, noting the lack of detail.

Some simply do not trust Russia.

One European diplomat pointed to the ongoing energy crisis and how Gazprom PJSC appeared to weaponise a commercial negotiation by pressing Moldova to delay its incorporation of European Union energy reforms to secure a lower gas price.

Other Russian proposals may find wider support.

One, made by Economy Minister Maxim Reshetnikov in a briefing this week, is for nations to adopt a technological neutrality principle that would declare any energy source clean if it produces no CO2 emissions.

In the case of nuclear energy, he may be pushing at an open door.

The European Commission is expected next month to announce a so-called taxonomy of energy sources that would accept nuclear power as green and natural gas as a transitional fuel.

Both decisions would have investment implications for energy companies and states, boosting Russia's green credentials in particular.

Russia wants hydroelectricity and so-called blue hydrogen - made using natural gas and with the resulting CO2 emissions captured - to be considered climate-friendly as well.

And it wants its vast Siberian forests to be treated as a source of carbon offset credits.

The potential value of such moves would be significant for the Russian gas industry and exporters that could soon face EU carbon border tariffs.

Yet, both are likely to face resistance, because technologies needed to capture carbon and measure the incremental CO2 absorption of Russian woodlands are not yet in place.

Forest credits will have to be negotiated bilaterally with the EU, a potentially complex process, said Mr Alexey Kokorin, head of the World Wildlife Fund's climate and energy programme in Russia.

A further goal, to get recognition of the longer growth cycle of Russia's cold-weather forests, would need more global agreement - a prerequisite for any feasible carbon absorption project in the region, he said.

"Even government slides and charts show that the government doesn't intend to start cutting CO2 emissions until after 2030," said Mr Kokorin.

"That isn't great for the environment, but at the same time at least they are being honest about what they're ready to do."

Russia plans to approve its national strategy for low-carbon development before the climate summit, according to Mr Reshetnikov.

The targeted scenario in the ministry's presentation assumes emissions cuts of 1.6 billion tonnes of CO2 equivalent by 2050.

The business-as-usual scenario is far less ambitious, with a reduction of only 460 million tonnes.

The nation of 144 million dumps 4.1 per cent of all carbon dioxide into the atmosphere each year, according to the World Resources Institute, a Washington-based climate think tank, making it one of the largest emitters.

Nearly 90 per cent of all energy Russia consumes comes from carbon-heavy sources, according to the International Energy Agency, above the global average of about 80 per cent.

Climate Action Tracker, a UK-based non-profit, rates Russia's roadmap for meeting climate targets under the 2015 Paris Agreement as "Highly Insufficient", up from rock-bottom "Critically Insufficient" before an update last November.

But Russian Deputy Prime Minister Alexander Novak argued last month that his country's power generation was "one of the most progressive" among major economies, because nuclear, hydroelectric and renewable energy sources contributed 41 per cent of electricity generation, while 46 per cent came from natural gas.

The truth may lie between. In terms of per capita CO2 emissions, Russia substantially underperforms compared with the EU and China, but beats the US, according to World Bank data from 2018, the latest available.

The international community will miss an opportunity if it fails to welcome Russia to the negotiating table and take its positions seriously, whatever Mr Putin's motivation, according to Dr Alina Averchenkova, a policy fellow specialising in governance and legislation at the London School of Economics Grantham Research Institute on Climate Change and the Environment.

Russia "has about 20 per cent of the world's forest cover", she said. "So you can't ignore that Russian forests are an important means to sequester carbon, or that it's important that carbon stored in the Russian permafrost stays there."