Wilderness or wildlands (usually in the plural) are natural environments on Earth that have not been significantly modified by human activity or any nonurbanized land not under extensive agricultural cultivation. The term has traditionally referred to terrestrial environments, though growing attention is being placed on marine wilderness. Recent maps of wilderness suggest it covers roughly one quarter of Earth's terrestrial surface, but is being rapidly degraded by human activity. Even less wilderness remains in the ocean, with only 13.2% free from intense human activity.
Early conservationists advocated the creation of a legal mechanism by which boundaries could be set on human activities in order to preserve natural and unique lands for the enjoyment and use of future generations. This profound shift in wilderness thought reached a pinnacle in the US with the passage of the Wilderness Act of 1964, which allowed for parts of U.S. National Forests to be designated as "wilderness preserves". Similar acts, such as the 1975 Eastern Wilderness Act, followed.
The U.S. concept of national parks soon caught on in Canada, which created Banff National Park in 1885, at the same time as the transcontinental Canadian Pacific Railway was being built. The creation of this and other parks showed a growing appreciation of wild nature, but also an economic reality. The railways wanted to entice people to travel west. Parks such as Banff and Yellowstone gained favor as the railroads advertised travel to "the great wild spaces" of North America. When outdoorsman Teddy Roosevelt became president of the United States, he began to enlarge the U.S. National Parks system, and established the National Forest system.
Forty-eight countries have wilderness areas established via legislative designation as IUCN protected area management Category 1b sites that do not overlap with any other IUCN designation. They are: Australia, Austria, Bahamas, Bangladesh, Bermuda, Bosnia and Herzegovina, Botswana, Canada, Cayman Islands, Costa Rica, Croatia, Cuba, Czech Republic, Democratic Republic of Congo, Denmark, Dominican Republic, Equatorial Guinea, Estonia, Finland, French Guyana, Greenland, Iceland, India, Indonesia, Japan, Latvia, Liechtenstein, Luxembourg, Malta, Marshall Islands, Mexico, Mongolia, Nepal, New Zealand, Norway, Northern Mariana Islands, Portugal, Seychelles, Serbia, Singapore, Slovakia, Slovenia, Spain, Sri Lanka, Sweden, Tanzania, United States of America, and Zimbabwe. At publication, there are 2,992 marine and terrestrial wilderness areas registered with the IUCN as solely Category 1b sites.
In Western Australia, a Wilderness Area is an area that has a wilderness quality rating of 12 or greater and meets a minimum size threshold of 8,000 hectares in temperate areas or 20,000 hectares in arid and tropical areas. A wilderness area is gazetted under section 62(1)(a) of the Conservation and Land Management Act 1984 by the Minister on any land that is vested in the Conservation Commission of Western Australia.
The percentage of land area designated "wilderness" does not necessarily reflect a measure of its biodiversity. Of the last natural wilderness areas, the taiga┤which is mostly wilderness┤represents 11% of the total land mass in the Northern Hemisphere. Tropical rainforest represent a further 7% of the world's land base. Estimates of the Earth's remaining wilderness underscore the rate at which these lands are being developed, with dramatic declines in biodiversity as a consequence.