Ancient wood points to arctic greenhouse
By Sid Perkins
Chemical analyses of wood that grew in an ancient arctic forest suggest that the air there once was about twice as humid as it is now.
About 45 million years ago, forests of redwoods grew on what is now Axel Heiberg Island, a Maryland-size landmass off the northern coast of Canada. At some sites, wood from those trees is exquisitely preserved, apparently changed only by desiccation and slight compression by surrounding sediments. “It’s like driftwood,” says A. Hope Jahren, a geochemist at Johns Hopkins University in Baltimore.