Earth is in danger. Whether you blame global warming on people, the undeniable fact is that rising sea levels, air pollution and deforestation are hurting the planet in irreversible way. The landscape is changing and the big adventures you are planning for the future may have to reflect that. Some national parks are shrinking, rainforests are drying out, and stunning islands are risking submersion. Hundreds of animal and plant species face extinction as they lose their natural habitat.