Which factor posed the greatest challenge to developing natural resources in siberia?

The most important factor that posed the greatest challenge to developing natural resources in Siberia was the climate. It poses a big problem because of the big layer of ice through out most of the year, in summer there's forming of wast marshlands, the ground becomes very unstable, there's big deposits of trapped methane which lately creates craters when released, in the winter temperatures know to drop to -50 or more...