* Russian goal for Copenhagen too weak -- environmentalists
* Permafrost melting in Russia's Yamal peninsula
* Some Russian scientists say global warming natural
* Arctic residents tell of hungry polar bears scavenging
By Amie Ferris-Rotman
MARRESALE, Russia, Oct 9 (Reuters) - The snows are late in coming on the Arctic Yamal peninsula where moist, dark permafrost entombed for 10,000 years crumbles into the sea at the top of the world.
Western scientists and environmentalists say collapsed river banks, rising tide waters and warmer winters in northwest Russia are clear signs of climate change, but they add Russia is in denial, ignoring a potentially disastrous "methane bomb".
At a state-run meteorological station at the Marresale port on the Kara Sea, around 500 km (311 miles) north of the Arctic Circle, its director said migrating geese arrived a month earlier than usual this year, in May, as temperatures rose.
Over the last six years that Alexander Chikmaryov has worked at the station, the sea coast has eroded by at least 2 metres (6.5 feet) and hungry polar bears seeking alternative food have clawed into tins of condensed milk in his wife's pantry.
The first snows usually fall by late September.
As a string of recent reports warn of dire consequences from global warming, the U.N. wants about 190 nations to agree a new climate pact in December in Copenhagen to succeed the Kyoto protocol.
But for Chikmaryov, global warming does not exist: "Whoever made that ridiculous idea up spends too much time at home," said the 58-year old, surveying an exposed strip of permafrost from a mud bank that has collapsed, giving way to streamlets littered with goose skeletons.
Geographer Fyodr Romanenko of Moscow State University agreed there is no proof human activity has damaged the environment. The up to 4 degree Celsius (7 Fahrenheit) rise felt across parts of the Arctic in the last 30 years could be part of millennia-old fluctuating weather patterns, he said. Other researchers disagree, saying the frozen, sparsely populated Yamal region 2,000 km (1,250 miles) northeast of Moscow holding a quarter of the world's known gas reserves and home to the Nenets tribespeople, is testament to climate change.
According to a paper in the scientific journal Global Change Biology published this week by Bruce Forbes of Finland's Arctic Centre, rising temperatures are making the Arctic tundra greener, adding significant growth of shrub willows over the last thirty years.
The world's largest country has a thick band of permafrost -- which contains organic matter whose microbes can emit the powerful greenhouse gas, methane -- stretching from Murmansk near Finland to the far eastern region of Chukotka near Alaska.
Environmentalists fear melting permafrost from rising temperatures will accelerate global warming.
"We are appealing to world leaders as this issue is overlooked in Russia... there is a carbon, or methane bomb embedded in our earth," Vladimir Chuprov, head of the Russian energy unit at environmental group Greenpeace, told Reuters.
He added that Russia -- which has permafrost covering 60 percent of its land -- most likely holds the world's biggest methane threat. By 2050, vast amounts of methane will "explode into the air" from Russia's melting permafrost, Chuprov said.
The United Nations panel of climate scientists says warming is happening faster in the Arctic than the global average. As reflective snow and ice retreats, it exposes darker ground and water that soaks up ever more heat.
"Methane emissions from tundra are likely to accelerate," it said in a 2007 report.
Ed Miliband, Britain's Secretary of State for Energy and Climate Change, said earlier this week in Moscow that it was in Russia's interest to reduce carbon emissions.
"Unchecked global warming will be bad for Russia," he told reporters. "There are 5,000 miles of rail track built on permafrost, which will crumble as a result of this melting".
So far, rich nations have offered emissions cuts averaging 11-15 percent below 1990 levels by 2020. Poor nations want cuts of at least 40 percent to avert the worst of climate change.
Russia, which along with the United States was accused by environmentalists of delaying Kyoto, has alarmed activists by saying it will release more greenhouse gases in 2020 than now under any new U.N. emissions treaty.
Russian President Dmitry Medvedev in June boasted his country would reduce emissions by 10-15 percent from 1990 levels by 2020. But in reality, this means a 30 percent rise from current levels since emissions tumbled after the collapse of the Soviet Union and its smokestack industries.
"We are so angry about this and completely oppose it," Greenpeace's Chuprov said. Almost all other industrialised nations are planning deep cuts from current levels.
To see a TABLE on rich nations' greenhouse gas emissions: [ID:nLN206032]
To see a FACTBOX on U.N. climate talks [ID:nLI190241]
(Reporting by Amie Ferris-Rotman, additional reporting by Robin Paxton in Moscow)