Human-caused climate change is indeed responsible for increasing incidents of extreme heat waves and rainfall over the past decade, a new, detailed scientific analysis shows.

The woman leading a front-running party in Alberta's provincial election has cast doubt on the widely-accepted scientific theory that human activity is a leading cause of global warming.

More people may have been infected by the virus that causes bird flu than previously thought, and the number of deaths from H5N1 infection may have been "overestimated," according to a study in the journal Science.