When you think about threats to national parks, you can point to air pollution, water pollution, development on a park's boundaries, and genetic bottlenecks affecting a park's wildlife. But few people seem to think about climate change. Well, the National Parks Conservation Association wants you to start thinking about it.

For over 80 years, hikers and mule riders have enjoyed—or endured—trips up and down the South Kaibab Trail at Grand Canyon National Park. That's a lot of footprints, and the iconic route will receive a major, multi-year makeover starting in May 2009.

Can you hear me now? Verizon Wireless wants an affirmative answer to that question if you're in Sequoia and Kings Canyon national parks, and says it needs a cellphone tower possibly 80 feet tall in Kings Canyon to get it.

Floating face down in the Caribbean, with snorkel clenched in your mouth, lacks the structure, the regimentation, of observing the natural world in the way we’ve grown up to accept while walking through a forest, strolling through a meadow, or hiking up a mountain. Clouds of neon blue tangs drift by while black-and-yellow striped sergeant majors flit about, lacking the tangs’ regimented approach to life in the ocean.