For Russia, there are two types of fires raging across Siberia: the kind the authorities are fighting and the others they are allowing to burn.

That’s because Siberia is so vast that huge fires can burn without threatening any major settlements, transportation systems or infrastructure — but are still part of a swath of infernos that together are larger than all the other blazes around the world.On one level, the Siberian fires are part of an annual cycle. But many climate experts see the staggering scope of this year’s fires as another sign of greater fire risks on a warming planet that is potentially being made even hotter by huge carbon emissions from the blazes.

Russia is fighting more than 170 forest fires in Siberia that have closed airports and roads, forced widespread evacuations and sent a pall of smoke across the North Pole. But it has abandoned dozens more fires covering thousands of square miles, with no effort to fight them.

As Russia faces one of its worst fire seasons, environmentalists say there is little urgency about an event that officials play down every year.

“For years, officials and opinion leaders have been saying that fires are normal, that the taiga is always burning, and there is no need to make an issue out of this. People are used to it,” said Alexei Yaroshenko, a forestry expert with Greenpeace Russia. The taiga is a belt of coniferous forest around the planet at between 50 and 60 degrees north of the equator.

As Russia increasingly confronts extreme weather associated with climate change, the rapid spread of fires in Yukutia — a vast forested Siberian region around the size of Argentina — came with drought, some of the hottest weather on record and strong winds.

The fires raging in Siberia are bigger than fires in Greece, Turkey, Italy, the United States and Canada combined, with analysts warning that this year could surpass Russia’s worst fire year, 2012, according to Yaroshenko.