In the past century, humans have cut down an area of forest equivalent to the entire US and every year, another 10 million hectares are lost. These changes undermine vital ecosystem services we all depend on and the loss of nature threatens more than half of global GDP. Forest conservation and restoration are cost-effective and scalable methods to combat the loss of nature. UpLink and 1t.org are launching the Trillion Trees: Restoration at Scale Challenge which calls for ecopreneurial ideas that enhance carbon sequestration.