Can We Give Up Half The Earth To Nature? Kentuckians Already Have.

The renowned biologist E.O. Wilson has proposed that we address the biodiversity challenge by giving up half the Earth to the natural world. In his 2016 book Half Earth – Our Planet’s Fight For Life, Wilson made a powerful case that humanity could afford to give half the Earth over to nature, while still allowing humans to thrive.  Many have challenged his proposition by saying that with a growing population and rising expectations of people in developing countries, we can’t give up any more land or water bodies to the natural world. Who is right? If we use Kentucky as an example, it is easy to see that Wilson is entirely correct.

Before we get to that, we need to discuss biodiversity. (For some definitions and background, see this article by Stuart Pimm).  There is a huge amount of gloom and doom surrounding a perceived biodiversity crisis. Some are calling this period the sixth extinction. Others say that insect populations are collapsing all over the world. There is a surfeit of end-of-the world ideation. We have been through this before. I vividly recall the end-of-the-world cries about the population bomb, initially promulgated by Paul Ehrlich, who has a consistent record of being wrong. Before the Clean Air Act and the Clean Water Act, we had predictions of the collapse of civilization due to pollution.

Some of these things could have come true, but we decided to fix them and we did. We humans, when we put our minds to it, are very good at fixing daunting problems. Whether it is climate change or the biodiversity challenge, we have been held back from making progress for the last four years, but now we are beginning to make rapid progress.

In an outstanding assessment by Emma Marris in The Atlantic, we can see the true status of biodiversity in the world now. Yes, too many species are threatened and endangered, and too much habitat has been lost, but we are not in the middle of a mass extinction. 902 species tracked by the International Union for the Conservation of Nature have become extinct since 1500. That is too many, but it is less than 0.7% of the species that IUCN tracks. Many more species are making extraordinary comebacks. Consider the wolf, American bison, or any number of other species that we have brought back from the brink of extinction. A small number of plant and animal species have seen population collapses – ash trees, chestnut trees, frogs, and others. Many more have seen population increases.

This is not to minimize the threats to many species. In Kentucky, in my lifetime, American chestnut, white and green ash, American elm, and Eastern hemlock have seen dramatic declines in populations due to insects and diseases that we introduced through careless import of contaminated horticultural products and untreated wood products. Yet none of these are extinct, and each of these trees has a dedicated groups of scientists, practitioners, and enthusiastic amateurs working to make sure they don’t disappear. With continued hard work, all of these trees will be brought back from the brink and will restore our forests.

What we need now is not only restoration efforts to bring these species back, but a massive effort to prevent more non-native insects and diseases from doing further harm. Many of us worry about invasive species, but the really important ones, economically and ecologically, are imported pests and pathogens, not plants. The economic and ecological impact of bush honeysuckle, considered a nemesis by many,  is trivial compared with the cost of the loss of white ash. And that loss could easily have been prevented if we had established tighter restrictions on the import of living plants and untreated wood products. Despite some improvements, our ability to prevent the next chestnut blight or emerald ash borer is too limited. 

Now back to the Half-Earth idea. The amount of forest land in Kentucky has increased from 20% in 1920 to 50% now, as farmers abandoned marginal lands and we became more urban. Deer, elk, beaver, otter, turkeys, bears, and coyotes have all returned, the first four with help from the Kentucky Division of Fish and Wildlife, the last two on their own. During the pandemic shutdown, I saw a beautiful coyote a couple of blocks from my downtown Lexington church, and a bear was recently seen wandering through the University of Kentucky campus. Kentucky is rewilding itself and this is good.

This rewilding is not without problem, such as the loss of trees mentioned earlier, but overall, Kentucky is a great example of why Professor Wilson is right. We can indeed allow the natural world to take over half of our state, and if we can do it, other places can as well. This is not to suggest that we simply walk away from that land, or lock it up. We need to dramatically improve the management of our natural resources to ensure that they remain healthy and productive. This management provides jobs, and allows continued use of these wild lands for multiple purposes, the famous 4 Ws of resource management: Wood, Water, Wildlife, and Recreation (say it out loud).

I am a realist, and understand that we have tremendous challenges, especially the climate crisis. So far, climate change is benefitting Kentucky with increased rainfall and longer growing seasons, but this may not continue. And we can’t forget that climate change is wreaking havoc throughout the world. But for Kentuckians, the natural world around us continues to thrive and provide us with immense benefits. 

So, the next time you hear people bad-mouth the Half Earth idea, tell them “Yeah, we Kentuckians are already doing it.”  And remember this as well: “There is no point in being pessimistic, it doesn’t work anyway.”

Picture of E.O. Wilson

E.O. Wilson, the renowned biologist who proposed the Half Earth idea

A picture of the books Half Earth - Our Planet's Fight for Life by E.O. Wilson

Half Earth, the 2016 book by E.O. Wilson

Emergence hole of emerald ash borer in a white ash tree

The characteristic D-shaped exit hole of an adult emerald ash borer, Agrilus planipennis after emergence from a white ash, Fraxinus americana.

Eastern hemlock trees killed by hemlock woolly adelgid

Hemlock trees, Tsuga canadensis, killed by hemlock woolly adelgid, Adelges tsugae

A picture of Kentucky forests in early spring

Kentucky’s diverse forests in early spring



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