So, in effect, to pin down the role of human influence on climate in the winter that has just ended, we need to roll the weather dice again thousands of times. (climateprediction.net)
But I wouldn't look for fresh findings there to up - end the basic picture of a growing human influence on the climate system. (dotearth.blogs.nytimes.com)
As The Right Climate Stuff team points out, we can not possibly model or distinguish human influences on climate change, without first understanding and modeling natural factors. (townhall.com)