Since the Industrial Revolution there has been a rise in the amount of carbon dioxide released into the atmosphere, which in turn causes global warming. One of the more obvious affects of global warming is climate change. In Chapter 5, Marris discusses the affect of climate change on various species in different ecosystems across North America. For example, she mentions how the “pika,” a small mammal that lives in the West, is slowly dying because according to an experiment conducted in the 1970’s these mammals are not able to survive in temperatures over seventy-eight degrees (Marris 73). With global warming, the temperature of the Earth is steadily increasing and a major concern for scientists is how to protect species like the “pika” from extinction. Over time the population of species who need to live in cooler conditions will decrease because given the cone shape of mountains, the higher up the species goes the less land they will be able to occupy. Consequently, scientists and conservationists introduced the idea of “assisted migration” as a way to “save biodiversity under threat from climate change…” (88).
However, this proposal is rather idealistic because there are many species that suffer from climate change and with “assisted migration” there is always the risk that the species might become invasive. Ecologist Hellmann has conducted a research experiment in British Columbia to determine whether or not the Garry oak will migrate further north in response to climate change (85). In conclusion, Hellmann was concerned about the extent to which assisted migration could protect biodiversity from climate change. She believes that people are only going to want to save the “important” species i.e. timber and wood, but other species like microbes or beetles will be left to fend for themselves. Ultimately, the determining factor behind what species to assist will be based on finance because there is a lack of funds for assisted migration. The only other way to get funds is through private corporations, which will most likely want to profit from the experiment.
Assisted migration for some species would be useful in an urban setting. More specifically, species such as trees or other small, harmless organisms would be valuable in cities. Given the large population of cities like New York City, if there are small and harmless organisms that need to be in a colder climate, it would be beneficial to move them to an urban area. Through educating communities about climate change and its affect on biodiversity, people will be more receptive towards those organisms. With the current green movement people in general would like to live closer to nature. However, one limitation of assisted migration in urban areas is the lack of space for organisms to live. If these organisms originally come from a wide, open area it would take time for it to adjust to the smaller space. Furthermore, as Marris pointed out in the chapter, there is also the possibility that this new species might become invasive and cause another species to go extinct as a result of its migration. In an urban setting there needs to be a specific plot of land set aside for the new species that closely resembles its previous ecosystem to make its transition easier. Then, slowly the species will be able to adapt to the new ecosystem and thrive there.
