Ecologists and environmental advocates on Thursday called for swift action to reintroduce species into the wild as scientists at the University of Cambridge in England found that 97% of the planet\u0026#039;s land area no longer qualifies as ecologically intact.\u0022Conservation is simply not enough anymore,\u0022 said financier and activist Ben Goldsmith. \u0022We need restoration.\u0022Just 3% of world’s ecosystems\u0026nbsp;now remain intact. Conservation is simply not enough anymore. We need\u0026nbsp;restoration. https://t.co/iWcLxAoLWn— Ben Goldsmith (@BenGoldsmith) April\u0026nbsp;15, 2021The authors of the study, published in the journal\u0026nbsp;Frontiers in Forests and Global Change, expressed alarm at their findings, which showed that\u0026nbsp;of the 3% of fully intact land, much lies in northern areas which weren\u0026#039;t rich in biodiversity to begin with, such as boreal forests in Canada or tundra in Greenland.\u0026nbsp;The amount of ecologically intact land \u0022was much lower than we were expecting,\u0022 Dr. Andrew Plumptre, head of the Key Biodiversity Areas Secretariat at Cambridge and lead author of the study, told Science News.\u0026nbsp;\u0022Going in, I\u0026#039;d guessed that it would be 8 to 10%,\u0022 he added. \u0022It just shows how huge an impact we\u0026#039;ve had.\u0022The researchers examined whether natural habitats had retained the number of species which were present in the year 1500—the standard used by the International Union for the Conservation of Nature to assess species\u0026#039; extinction.Earlier research using satellite imagery led to estimates that 20 to 40% of the planet had retained its natural biodiversity. But areas including dense forests, which can appear intact from above, were found to be missing numerous species.\u0026nbsp;The researchers linked the loss of unscathed land to hunting and other destructive human activities, disease, and the impact of invasive species. According to The Guardian, the study may underestimate the intact regions because it does not\u0026nbsp;\u0022take account of the impacts of the climate crisis, which is changing the ranges of species.\u0022Only 11% of the land still considered intact was found to be in officially protected areas, but much of the intact regions \u0022coincide with territories managed by indigenous communities, who have played a vital role in maintaining the ecological integrity of these areas,\u0022 the researchers wrote.In light of the study, advocates including author George Monbiot and ecologist Alan Watson Featherstone called for \u0022rewilding,\u0022 or species reintroduction in affected areas.Rewilding isn\u0026#039;t a luxury. It\u0026#039;s essential to protect the world\u0026#039;s living systems. https://t.co/WbqrTU3VTR— George Monbiot (@GeorgeMonbiot) April 15, 2021If anyone wonders why we have a UN Decade on Ecosystem Restoration \u0026amp; rewilding has to become a major focus for humanity this report provides the answer: just 3% of ecosystems remain in a healthy fully functioning state with all their constituent species. https://t.co/lvGnS6QiOA— Alan Watson Featherstone (@AlanWatsonFeat1) April 15, 2021The reintroduction of up to five species could help restore 20% of the planet to previous levels of biodiversity, the study found.\u0026nbsp;\u0022Examples would include reintroducing forest elephants in areas of the Congo Basin where they have been extirpated, or reintroducing some of the large ungulates that have been lost from much of Africa\u0026#039;s woodlands and savannas because of overhunting (e.g., buffalo, giraffe, zebras etc.), as long as overhunting has ceased,\u0022 the researchers wrote.Previously, the rewilding of gray wolves in Yellowstone National Park in the U.S. led to a resurgence in the park\u0026#039;s ecosystem.