Among Sequoia and Kings Canyon National Parks' rich diversity of plants and animals are other elements that are not as obvious but equally important. An air flow eddy circles around the neighboring San Joaquin Valley and carries air pollution from human activity and industry into the parks. This affects visibility, the health of people and natural resources in the parks. Air quality monitoring in the parks is making a difference by providing important data to notify the public of health hazards on "bad air" days and to help both state and federal agencies in their efforts to improve air quality. In the past the landscapes of these parks were regularly shaped by fire. The positive results benefited both plants and animals, such as encouraging the regeneration of plants, which in turn can benefit wildlife. After decades of fire suppression the landscape has severely changed, but efforts have been made to once again allow fire to return to its place as part of the natural cycle in the Sierra Nevada. As the population of the state continues to increase and urban areas grow, so does the use of outdoor lighting. This has an environmental impact on dark skies. Where once dark skies provided the perfect backdrop to distant stars and planets, they now glow more from the lights of urban areas. By recording these changes and providing education, park staff can increase appreciation of the night skies and suggest ways that we all can take a more active role returning a natural glow to our night skies.