Words on how to remove Carbon Dioxide from sources that pollute the air.   The two biggest items which can destroy the atmosphere is smokestacks & tailpipes of cars & trucks.

Some of the puzzles that people list for the public get indexed by the search engines (like Google). Some people find those puzzles and cannot figure out how to make a puzzle of their own. So this page now has the navigation sidebar.

There are now buttons on the puzzle so that you can get a clean page, in either HTML or PDF, that you can use your browser's print button to print. The PDF format allows the web site to know how large a printer page is, and the fonts are scaled to fill the page. The PDF takes awhile to generate. Don't panic!