< or not we lay global warming at man’s feet, there is no doubt that humans have wrought widespread changes on Earth and the species that inhabit it. From agriculture and animal domestication to deforestation and the introduction of invasive species, we have both knowingly and unwittingly created, modified, and destroyed plants, animals, and habitats.
A recent survey of the site near BP’s formerly leaky oil well revealed a new casualty of human activity: deep-water coral is dying from exposure to toxins. Although the oil from the well, which drifted seven miles from the well to the site of the coral, may not be the culprit, biologists are leaning towards that explanation. The severity and scale of the coral death points not to the relatively small volume of oil that seeps naturally through the seafloor of the Gulf, but rather to the large amounts of oil that leaked from BP’s man-made well in April.
The discovery of dying coral in the Gulf supports experts’ assertions that the marine life in the Gulf still needs to be monitored if we are to comprehend the full extent of the leaking well’s damage. And this is another thing we humans do—we acknowledge that we affect other species’ survival. Just look at the endangered species list.
In fact, determining the status of species on that list can be contentious. While the public generally doesn’t worry about the status of endangered tropical bugs, bigger animals get bigger press, and polar bears are pretty big. During George W. Bush’s presidency, the Department of the Interior labeled polar bears as “threatened,” a step below endangered on the in-danger-of-extinction scale. With this status, polar bears don’t reap many benefits, but U.S. District Judge Emmet Sullivan has asked the Department of the Interior to specify whether the bears qualify as endangered. If the bears were upgraded to endangered status, the government would have a legal obligation to take steps to protect the bears.
Unfortunately for the bears’ welfare (and that of walruses, which are nearing endangered status themselves due to the effect of global warming on their habitats), this opens up a political can of worms. Under the Endangered Species Act, protecting endangered species means preserving their natural habitat—in the case of polar bears, protecting Arctic ice. Because warming is accelerating the ice’s melting and putting polar bears’ survival in danger, this would require legislation to prevent planetary warming, namely, cutting down on greenhouse gas emissions. Due to the fierce debate over global warming and emissions standards, the government’s eagerness to avoid this requirement may keep polar bears off the “endangered” list, even if they belong on it.
Interestingly, humans may be affecting polar bears, but they are also changing the status of a different species. Rather than go hungry or swim excessive distances to find their prey, the bears are turning to snow goose eggs for meals, which in turn threatens snow geese’s survival. If the bears wipe out the geese, then both species would suffer—the geese would die out, and the bears would have to find another supplemental food source. Luckily for both, the time during which polar bears come ashore and the period when goose eggs are laid do not always coincide; some years the baby geese are born before the bears have a chance to eat the eggs. These non-overlap years will allow the snow goose population to rebound.
Polar bears aren’t the only species that affect others. A recent study found that fruit flies’ mating preferences may be determined by the bacteria species that live in flies. Previous experiments have shown that due to evolution, when a group of fruit flies is split in two and each half is allowed to reproduce in separate environments, each populations will develop a preference for mates raised in the same environment. However, when researchers created food environments, feeding one population of fruit flies on sugar and another on starch, a fly would begin choosing mates who ate from its own food source within the second generation, far too soon for evolution to have had an effect. The culprit was a starch-eating bacteria called Lactobacillus plantarum, which lives in flies’ cuticles. Because the cuticle is the site from which flies produce the pheromones that attract a mate, the presence of L. plantarum can alter the chemical signal that flies emit so that it attracts only a mate raised on starches.
But although non-humans can also affect the populations of other species, only humans have the urge to undo their influence. The reason there’s an endangered species list for polar bears and walruses to be on in the first place is that humans would like to preserve species near extinction. This well-meaning urge to save species extends to preserving the planet itself, which is one of the reasons scientists advocate action against global warming (another reason is that broad global weather changes threaten our species personally).
Some see the answer to global warming in geoengineering, altering the planet itself, to reduce its temperature. For example, the ash spewed into the air by a volcanic explosion reflects sunlight away from the Earth, measurably reducing global temperatures. Some advocates of geoengineering suggest that humans recreate similar alterations to the atmosphere to increase its reflectivity and thus cause global cooling. However, without a great deal more planning and research, geoengineering could be more harmful than helpful. It would be dangerous for us to try to reverse the damage done by global warming without reflecting on the potential complications of our well-intentioned meddling.
Before we contemplate drastic changes to the planet, it’s important that we take a step back and realize it’s not all about us humans. The world isn’t our playground, as modern environmentalism has urged us to acknowledge, but this doesn’t mean we should shoulder the egocentric burden of planetary protectors—after all, life on Earth has survived without us for thousands of years, as some species died off while new ones evolved. When its population dwindled, T. rex didn’t get to be on an endangered species list. Maybe it would have survived if humans had been around to put it on one, but the world may not have been better off.
Does this mean that we should abandon our quests to protect endangered species and reverse global warming? Not necessarily. I just think it’s important to bear in mind that we are not the supreme guardians of the planet, and this consciousness should pervade the choices we make, particularly those about drastically altering Earth through methods like geoengineering—no matter how positive our intentions.
-Sophie Bushwick is a Carletonian columnist.