The Yamal peninsula, a remote region of north-west Siberia, is under serious threat from climate change as Russia’s ancient permafrost melts. It is one of the world's last great wildernesses and home for the indigenous Nenets people where they have herded their reindeer for 1000 years. Traditionally the Nenets travel across the frozen Ob river in November and set up camp in the southern forests. These days this annual winter pilgrimage is delayed. Herders say that the peninsula's weather is increasingly unpredictable, with unseasonal snowstorms in May, and milder longer autumns. In winter temperatures used to go down to -50C, now they are typically -30C. The snow is melting sooner, quicker and faster than before. Scientists are extremely concerned that if the global temperatures continues to climb, millions of tonnes of methane locked in the permafrost will be released. A ticking time bomb, a tipping point that will accelerate climate change to irreversible levels.