sort by best latest
Even better, we have a continent-sized filter, called forests and rainforests.
I like your thinking. For the filter to work, though, the city would have to be enclosed in a sealed dome, which might be a bit expensive.
You can help the HubPages community highlight top quality content by ranking this answer up or down.
Wouldn't it be cheaper and more effective to require every smokestack in the world to have scrubbing technology installed first?
Copyright © 2016 HubPages Inc. and respective owners.
Other product and company names shown may be trademarks of their respective owners.
HubPages® is a registered Service Mark of HubPages, Inc.
HubPages and Hubbers (authors) may earn revenue on this page based on affiliate relationships and advertisements with partners including Amazon, Google, and others.