But this often made things worse, because the depreciation took the value of small coins below the point at which it paid to melt them down.

ECONOMIST: The lessons of sound money from 1,000 years' experience

Asked about glacial melt, which many observers point to as evidence of global warming, Lindzen said the way glaciers change and move are phenomena largely unexplained.

CNN: Global warming: A natural cycle or human result?

While earthquakes have often been blamed for rock failures and landslides on mountain slopes, scientists also point at global temperature rises for rapid thawing of snowfields and glacial melt that can disturb the flow of snow-fed rivers.

BBC: Nepal floods change river course and threaten tourism