Atlantic Cities posts an interesting report: The Clean Air Act Actually Caused More Rain to Fall on Atlanta
According to the piece, the Atlanta region experienced a decline in summer rainfall in the 1950s, 60s and early 70s due to an in crease in particulate matter emissions from cars and factories.
As a result of the 1970 Clean Air Act that regulated and reduced these emissions, “particulate matter in the region dropped by about 40 percent. And summer rainfall rapidly bounced back, primarily in the form of more days with heavy rain.”
The reduction in car emissions has been great for air quality. But as we hail improvements in automotive technology, with a future that promises alternative fuels and autonomous cars, it’s important to keep in mind that car-dependency (and the sprawl that it enables) causes damage to another part of our environment: groundwater.
According to americanrivers.org:
“Impervious surfaces” such as roads, parking lots, and roofs associated with sprawling urban development significantly change natural river flow patterns and the recharge of underground water supplies.
Rainfall cannot soak into the ground through these surfaces and thus does not replenish groundwater supplies. Impervious surfaces also increase the amount and speed of water entering rivers and other water bodies.
The result is an increase in the severity and frequency of floods, the displacement and destruction of habitat for fish and other water dependent species, and a decrease in base flows in our streams and water in our aquifers.
As long as we’re paving over so much land with roads, parking lots and other kinds of sprawling infrastructure and development, dependency on personal cars will continue to do harm.
That extra rain we’re getting is hitting asphalt all over the metro area, and suffering damage because of it.
Photo from Flickr user JesseJamesHamilton