Activists are asking Europe's top rights court to fault Russia for creating a "climate catastrophe", saying Moscow's war on Ukraine is contributing to a spike in its greenhouse gas emissions.

Russian environmental group Ecodefense and 18 individuals filed a case with the European Court of Human Rights (ECHR) last year, saying Moscow's actions were worsening the global climate crisis, in violation of human rights.

"Russia is killing the climate," Ecodefense co-chair Vladimir Slivyak told AFP in a recent interview in Geneva.

He highlighted that Russian President Vladimir Putin had signed the 2015 Paris Climate accord, which set the target of limiting warming to 1.5 degrees Celsius above pre-industrial levels.

But he charged that Russia was failing to limit greenhouse gas emissions or reduce the extraction of fossil fuels.

Instead, he said internal policy documents show that Russia is planning "only growing extraction of coal, oil and gas" for the next decade at least.

"In some scenarios it is up 50 percent."

Slivyak, who left Russia in 2021 amid a crackdown on civil society ahead of legislative elections, said Russia's growing emissions were closely linked to its war in Ukraine.

While official statistics are unavailable, he said "there must be a big increase in greenhouse gas emissions during the war", with additional production lines for tanks and weapons as well as emissions when the arms are used.

At the same time, "Russia can continue the war only if it sells enough" of its fossil fuels, he said, urging more sanctions.

"If the world right now stopped buying fossil fuel from Russia, that would likely lead to the end of this war this year."

The plaintiffs filed their case last August, after first attempting to take it to Russia's Supreme Court, which refused to hear the claim.

Read: Study details huge emissions resulting from Russia's invasion of Ukraine

"We want the court to decide that the Russian policy... is dangerous for climate and the world," Slivyak said.

The idea is not so far-fetched.

In a historic ruling in April, the Strasbourg-based ECHR deemed that Switzerland was not doing enough to tackle climate change.

And the situation with Russia is far worse, said Slivyak, a 2021 winner of the Swedish Right Livelihood Award, which is often characterised as an alternative Nobel Prize.

"It's not about not doing enough, but about actually killing the climate," he said, slamming Russia for "undermining the international efforts".

While other countries were investing in innovations and technologies, "there is the largest-by-territory country on Earth that thinks it can ignore everybody else".

Ecodefense had asked the court to fast-track the case, as it did with the Swiss case and two other climate-linked cases heard in parallel.

But the court rejected that request last week, meaning the process could take a long time.

Last time Ecodefense helped bring a case to the court was in 2013, when it was among organisations asking for a ruling against Russia's foreign agent law, which requires anyone receiving backing from abroad to be listed as a foreign agent.

The court took nearly a decade to issue its ruling, and while the 2022 decision was in the organisations' favour, Slivyak said "it was too late", pointing out that the groups had already fled the country.

An earlier verdict, back when Russia still appeared amenable to being swayed by international opinion, might have altered the course of history, he suggested.

He acknowledged it was trickier this time.

Russia was expelled from the pan-European rights body the Council of Europe, of which the ECHR is part, after it launched its full-scale invasion of Ukraine in February 2022.

But complaints concerning violations allegedly committed by Russia before its September 16, 2022 exclusion from the body remain admissible at the court.

While Russia is likely to dismiss any ECHR decision, Slivyak insisted that getting a ruling in the case could be useful for shaping policy when Russia's "fascist dictatorship" one day falls.

Internationally too, he said, it could set a "precedent", pushing governments to adopt more ambitious climate policies.

"It could change the whole field."