The man hailed as a modern-day Darwin has a stark message for the future of planet earth - act now and go big on fighting climate change and protecting species - or else things will only get worse. Much worse.“If we fail to do it and a large portion of the biological diversity of the world is allowed to be exterminated, the generations, all the generations to come, that carelessness will be regarded as one of humanity's greatest failures."Alongside Sir David Attenborough, Edward O. Wilson is considered the world's leading authority on natural history and conservation.The 92-year old Harvard University naturalist has called for setting aside half the planet as a nature preserve..And in an interview in Boston with Reuters, he said that despite our differences, humankind is not too polarized to save the planet."We have... if we just take a little bit of care and measure what we will achieve by, in saving the rest of Earth's biology, and by setting aside more space than we have in the past, it will, it'll be one of our humanity's proudest achievements. “Today, species are going extinct at a rate not seen in 10 million years, with around 1 million currently on the brink. To limit the loss, the United Nations has urged countries to commit to conserving 30% of their land and water – almost double the area currently under some form of protection - by 2030.The so-called "30 by 30" target is in part inspired by Wilson's Half-Earth Project. First outlined in 2016, it calls for protecting half the planet's land and sea so there are enough diverse and well-connected ecosystems to reverse the course of species extinction.Now living in a retirement community… Wilson - who continues to write and is working on a book about ecosystems - is still optimistic humankind will do the right thing.If we don't, he says, the slope of human history will always be downward.Saving the planet from falling into the kind of downward spiral Wilson warned about will be the aim of COP26, the U.N. climate talks starting in Scotland on Sunday.