Only 40% of the world's forests are in good health

Many global environmental agendas, including halting biodiversity loss, reversing land degradation, and limiting climate change, depend upon retaining forests with high ecological integrity, yet the scale and degree of forest modification remains poorly quantified and mapped. By integrating data on direct and indirect forest pressures and lost forest connectivity, we generate the first globally-consistent, continuous index of forest condition as determined by degree of anthropogenic modification, which we term 9forest health9. Globally, only 17.4 million km2 of forest (40.5%) can be considered in high health (mostly found in Canada, Russia, the Amazon, Central Africa and New Guinea) and only 27% of this area is found in nationally-designated protected areas. Of all the world9s forests found within protected areas, only 56% can be considered in high health. Ambitious policies that prioritize the retention of forest health are now urgently needed alongside current efforts aimed at restoring the health of forests globally.