LONDON - Three of Europe's busiest airports reopened Monday afternoon after a dense volcanic ash cloud from Iceland dissipated and a no-fly zone was lifted. Up to 1,000 flights in Europe were affected by the closures.

Will the park's 2 million tourists still come when the glaciers are gone? Is the nation willing to spend $200 million to repair the cliff-hugging Going-to-the-Sun Road? Will climate change destroy the habitat of grizzly bears, bighorn sheep and other iconic animals?