An unfortunate and dangerous commonality persists among conversations concerning human-driven climate change. Often, the consequences of climate change are spoken of as something that will take place in the future, something that is decades from now. Naively, many even talk as if it is something that is still preventable if only we could convince people to take on a "green" lifestyle, industry to clean up its act, and policy makers to face overwhelming evidence. While those are worthy pursuits, that naiveté is dangerous.
Climate change is happening now. It is affecting ecosystems around the globe and causing drastic decreases in biodiversity. Organisms across land and sea are being forced to migrate, acclimate, adapt, or face extinction. As a Ph.D. student, I am researching such responses to increase our understanding of how some animals may respond to climate change through acclimation or adaptation (acclimation occurs when an individual exhibits some change in its behavior, morphology, or physiology in response to changes in its immediate environment; adaptation is an evolutionary process that occurs over generations as environmental pressures lead to certain heritable traits occurring more or less frequently among all the individuals in a population).
My current work investigates whether lizards can alter their nesting behavior to survive climate change. Climate warming is raising temperatures at nest sites used by many lizards to the point that they are becoming harmful and even lethal to developing embryos. It would be beneficial if lizards could choose shadier, cooler places to nest, which would buffer their offspring from effects of climate change. Recent research and some of my preliminary data suggest, though, that some lizards may be limited in their nesting behavior by a phenomenon known as philopatry—the tendency to return to one’s place of birth to breed (sea turtles are perhaps the most well-known example). If lizards are driven to return to the same nest sites year after year, they may not be able to adjust their nesting behavior and are therefore facing a dire fate under climate warming.
The idea of philopatry and its consequences for the lizards I study illustrate a link between the impacts of anthropogenic climate change on the natural world around us and why that concerns humanity. Like reptiles returning to their natal origins, we humans tend to have close ties to concepts of “home.” As a social species, we congregate amongst families and friends, neighbors and colleagues, businesses and patrons, governances and citizens. And much like the animals studied by my fellow scientists and me, the human response to rapid climate change is presently determining our fate.
People around the world are already facing consequences of climate change. Families are losing their homes and entire communities are being forced to relocate due to direct effects of human-driven climate change, such as rising sea levels, ocean acidification, toxically polluted water and air, and increased extreme weather events that cause flooding, heat waves, drought, and more. In places such as the Marshall Islands in the Pacific and Isle de Jean Charles in Louisiana, USA, some of the first “climate refugees” are facing displacement from the places their families have called home for generations.
The United Nations University Institute for Environment and Human Security estimates that 50 to 200 million of the world’s most vulnerable people could be displaced by 2050 due to climate change. And those numbers will increase dramatically by the end of the century. The greatest flood of climate refugees is likely to come from the Middle East and North Africa, which experts predict will begin happening in the next couple of decades. By the end of the century, those regions will be inhospitable, with choking dust storms and long-lasting heat waves increasing average daily temperatures to 50°C (~122°F). That means that by the end of the century, over 500 million people from those regions will be forced to seek refuge in other parts of the world or face extreme hardship and death in their homelands.
The numbers of climate refugees are increasing every day, and it is up to the rest of the developed world to determine our response. In the face of extreme consequences of human-driven climate change, we must prepare for the challenges that will come. The imminent collapse of communities and even whole societies in some parts of the world will lead to new domestic and economic pressures in those places that the displaced will seek refuge. This is not a potential scenario, and it is not preventable. This is a reality. And the better prepared we are for it, the better world we can create under climate change. The corporate and governmental systems in the less vulnerable parts of the world need to be prepared to handle this issue to prevent damage to their own communities while enabling support for climate refugees.
Some burgeoning programs, such as the US federal grants and corporate support for relocation of the residents of Isle de Jean Charles, are a good example of the type of action that will need to be taken. But even that is reactive, and we must act now to be proactive. I know that I am speaking passionately, and I am somewhat of an idealist. The reality of the situation is that the problem is extremely complex. There is no simple or easy way to plan the resettlement of entire populations. The global scale of this issue is honestly frightening. Yet, it must be done. And it will largely be up to our corporate and political bodies to lead the way because they are the only ones with the resources, the reach, and the power to handle such a large scale issue.
If you would like to discuss these ideas with me further, come find me on Twitter (@MikeACarlo), or you can explore my current project page at experiment.com/lizardnesting.