Park Service in 1916 did not alter fire control policies. The Leopold Report, however, soon did transform fire policy in Kings Canyon. In fact, Dr. Leopold used the sequoia groves in Kings Canyon as evidence of the need for proscribed burning and improved management practices. The 1964 Wilderness Act confirmed the findings of the Leopold Report and mandated controlled burning in the national parks and national forests, including Kings Canyon. As such, the National Park Service reintroduced fire into the grove as a natural process to prevent brush build up. By 1972, Kings Canyon had implemented a proscribed burn plan that spanned the entire park, including General Grant Grove. Controlled burns today remain a vital part of the National Park Service's efforts to manage Kings Canyon and General Grant Grove. Ozone pollution, climate change and the groves' future Another issue of growing importance to the Grove is anthropogenic air pollution. National Park Service employees fear that greenhouse gas emissions have increased temperatures, and that the increased temperatures have already negatively altered the habitats of the national parks and that ozone affects sequoia seedling growth. Research has indicated that climate change has already affected Kings Canyon. Rising temperatures have pushed the snow line higher into the mountains. The higher snow line will likely lessen water storage, change species' habitats, and make fires more severe. Because the sequoias of General Grant Grove thrive under a distinct set of conditions, the impact of climate change could result in habitat loss for the trees, as fewer areas within the park will retain the conditions necessary for the sequoias' survival. Specifically, an increase in the temperature could lead to failure in sequoia regeneration and increased mortality from long droughts. Current restoration plans aim to slow the effects of climate change through reducing air pollution within the parks and the greater San Joaquin Valley. Kings Canyon is among the leading parks in this effort. But since climate change occurs as a result of human activity mainly outside the park, the larger problems of air quality will continue to pose a challenge to the survival of the ancient trees despite efforts by the National Park Service to remedy the impacts. The park today General Grant Grove consists of a number of sequoia trees situated around a half-mile loop. Visitors have access to a number of trails, including Big Stump Trail, Redwood Canyon Trail, and the Big Baldy