By Tim Radford / <a href="climatenewsnetwork.net/human-impact-on-climate-is-100-years-old/">Climate News Network</a>
Source: Read full article at Truthdig
Our influence on the Earth’s environment has lasted for a century: the human impact on droughts and moisture patterns began at least 100 years ago, researchers now say.
US scientists used new analytic techniques and almost a thousand years of tree-ring data to build up a picture of drought and rainfall worldwide for the last century. And they report in the journal Nature that they have identified the human fingerprint upon climate variation as far back as the first days of the motor car and the infant aircraft industry.
The pattern of change, in which regions prone to drought such as the western US became more arid, grew visible between 1900 and 1949. The researchers saw the same pattern of drying in those decades in Australia, Europe, the Mediterranean, western Russia and southeast Asia.
At the same time more rain and snow fell in western China, much of central Asia, the Indian subcontinent, Indonesia and central Canada.
Clear signal apparent
Kate Marvel of the Nasa Goddard Institute for Space Studies, who led the research, said: “It’s mind-boggling. There really is a clear signal of the effects of greenhouse gases on the hydroclimate.”