Image credit: Anthony Barnosky/Island Press
In 2006, a hunter discovered a "pizzly" in the Canadian Arctic. Half polar bear, half grizzly bear, the hybrid animal had never been documented by scientists. Some called it a fluke—a chance occurrence signaling the unpredictability of nature. Dr. Anthony Barnosky, however, believes the bear is a product of a changing world, and a sign of things to come.
His new book Heatstroke draws on his extensive research to paint a picture of a natural world that has been fundamentally altered by climate change—and offers new insights into how this grim future can be avoided.Recently, TreeHugger had the opportunity to talk to Dr. Barnosky about the book.
TreeHugger: Throughout history, ecosystems have expanded and collapsed, species have flourished and gone extinct. What is different about the changes in the natural world you are observing today?
Anthony Barnosky: There are three obvious differences. 1) People, and their impacts. More than 50% of terrestrial landscapes and much of the oceans now have an obvious human footprint. That means fragmentation of habitats that species formerly found continuous, invasive species, and ever-growing numbers of people consuming resources that formerly were available for other species. 2) The pace at which changes to the natural landscape is taking place today is far faster than species have evolved to adapt to. When species can't adapt fast enough, local or global extinction is the result. 3) Climate change. The warming of the globe is not only faster than most species alive today have ever witnessed, we are going into a new (hotter) climate state than they have ever experienced. Yes, global climate has been warmer in the past than we are predicting in the next century or two. But the key question is has it been warmer since most species on Earth that we want to save evolved? That answer is no.
TH: Species around the world are threatened by habitat degradation and poaching. Would you consider national parks and nature reserves the most potent tools available for protecting ecosystems and species? What would be more effective?
AB: Nature preserves and natural parks certainly are needed and a key piece of the conservation strategy of the future. We need to keep the ones we have, and also add more. But simply setting aside pieces of land and expecting the species that are there to survive well is not going to work given global warming. The reason is because as climate changes, we are pulling the climatic rug out from under species in the places we have set aside for them to flourish. If their climate isn't there, they can't be either. So we will need to augment our reserve system by establishing migration corridors of suitable habitat so that species can follow the climate they need as it shifts around the globe. In cases where that is not possible, we may have to move some species from places that they are dying out to places where they can flourish.
TH: In your book, you describe an ecological system that is increasingly stressed by a changing climate and unable to adapt due to confinement by human populations. Is the situation really this dire?
AB: Yes. When you put together what I call the 'Gang of Four'—habitat fragmentation, invasive species, human population growth, and global climate change—you create a situation that is far outside the bounds of what most species have experienced in their evolutionary history. It is certain that landscapes will change dramatically over the next century. What is uncertain is how many species will actually go extinct. It is likely the count will be high if we do nothing, but by taking conservation actions that recognize the unique position the Earth and its species are in, we can probably avert the worst.
TH: Ultimately, your book suggests, climate change could lead to the collapse of several ecosystems. What implications would this have for the planet's human populations?
AB: Ecosystems serve us. That's why ecologists have coined the term 'ecosystem services' to refer to the direct benefits we get from other species. Included are things like food, clean water, medicines, even the ability to do things like map the human genome. Virtually all of these services flow from having biodiversity at the levels we are accustomed to now. Collapse of ecosystems mainly means collapse of many species, that is massive reduction in biodiversity in a given ecosystem. The losses in purely economic terms would be staggering—in the billions of dollars annually. In my view even more staggering would be the losses of landscapes and species we love. We'd be passing to our grandchildren a black-and-white version of the technicolor world we live in.
TH: What can we do to prevent these worst-case scenarios?
AB: In the short run it's important to become more efficient in how we use fossil fuels. That's needed to buy us the time needed to switch over to an economy that emphasizes more carbon-neutral energy technologies. So yes, it really does make a huge difference to switch to those CFL lightbulbs, replace your car with a fuel-efficient model when you're ready to trade it in, and any number of other little things you can do that are listed at many websites (such as Cool Climate Network). Most of those energy savings also save you money so it's win-win. In the longer run, moving away from a fossil-fuel economy is going to take some legislative changes—things like trading in carbon credits, and making it feasible for alternative-energy startups to build, so another key way to help is to vote with those kinds of issues in mind, and hold leaders accountable.