Depleted ecosystems, dwindling forests, contaminated drinking water, and toxic soil. All due to what Canada’s Environment Minister John Roberts called in 1980 “the most serious environmental threat to face the North American continent.”
The cause? Acid rain. But flash forward to today, and the presence of sulfuric and nitric acids in precipitation throughout the continent has decreased tremendously, thanks to reductions in the emissions that cause them. Since 1990, carbon monoxide in the air has reduced by 74%, nitrogen dioxide by 57%, and sulfur dioxide by 89%, according to the latest data from the Environmental Protection Agency.
The researchers attributed the growth of acid rain — now defined by the EPA as any form of precipitation containing acidic components — to emissions from power plants and heavy industry precipitating into bodies of water and said it was likely to have increased around the mid-1950s. They called for proposals of new energy sources and the development of air quality emission standards.
Dr. Michael Rennie, a freshwater ecology professor at Lakehead University in Canada, said the story of acid rain across the continent serves as a lesson in moving other environmental issues forward.
“When you enact legislative change, you can impact the environment in the way that you want to, and we’ve seen that,” he said. “It took more than 20 years, but we’re starting to see biological recovery in a lot of these systems. We’re starting to see chemical recovery. So it’ll happen.”
Source: CBS News