Study shows human activity accelerating climate change

Researchers at Environment Canada have proven for the first time that human activity has affected the amount of precipitation that falls on North America.The scientists, co-led by Francis Zwiers and Xuebin Zhang, studied global rainfall data from 1925 to 1999 and compared it to 14 complex climate models.The observed changes, reports Zwiers, were larger than estimated from model simulations, implying that human activity is accelerating the rate of change in the earths climate. Human activity is creating a stronger water cycle, moving more water vapour away from the warmest parts of the planet and pushing it towards the poles, essentially making wet areas wetter and dry areas dryer, Zwiers explained to the Globe and Mail.The current flooding in Britain is consistent with the predictions but no specific event can be definitively attributed to climate change, Zwiers told The Chronicle Herald.Human induced changes have not previously been detected in global studies of precipitation, partly because drying in some regions cancels moistening in others, reducing the global signal, an Environment Canada summary says.Here the scientists used the pattern of changes in different latitude bands instead of the global average, it added.These are pretty big changes over the better part of the century and what were able to say from our study is that a substantial part of that change is due to human influence, Zwiers told The Chronicle Herald.