. >> laura kate anderson, a field organizer for the environmental group says such extreme weather eventsre also getting bigger. >> scientific consensus is that global warming is contributing to the increased precipitation. >> head scientist of the national climatic data center says you can link global warming to the increased frequency of extreme precipitation. in fact, a federally funded study concluded the global temperature has increased over the past 50 years and that is due primarily to human induced emissions of heat trapping gases. >> not all extreme events are going to become more frequent. for example, cold waves are going to become lesser frequent. and we're seeing that already. >> environment virginia hopes the study will encourage the obama administration to pass legislation that has stricter fuel efficiency standards and reduces carbon pollution for a new power plant. in leesburg, virginia, anny hong, 9news now. >> any warrants that the data goes back 60 years. the data used for this report and that is what other experts say, we have to be careful about. in fact, those who c