Use scientific evidence to counter the argument by climate-change skeptics that global warming might have positive effects.
How to Change Minds About Our Changing Climate (The Experiment, 2014), by Seth B. Darling and Douglas L. Sisterson, provides arguments backed by scientific evidence to use against climate-change skeptics who believe that climate change isn’t real or think that we can do nothing about it. In the following excerpt from Chapter 3, “Who says climate change is such a bad thing?,” Darling and Sisterson show how an increase in greenhouse gases would be unequivocally bad for the planet, despite claims from climate-change skeptics that global warming would actually be good.
You may know a Brad (or two or three). He’s that neighbor/brother-in-law/coworker/politician/TV personality/blogger who thinks this whole climate change thing is a bunch of malarkey, and he’s got arguments—and even some data—to back up his claims. He is a climate-change skeptic, and if you’re a member of the majority of folks who accept that climate change is happening and that it’s caused by human activity, he can be an exasperating thorn in your side. Brad may have ideological motives, or maybe he’s just fallen victim to the very same faulty arguments that he’s parroting to you.
While the claims of skeptics like Brad can seem outlandish, paranoid, and maybe even deceitful at times, perhaps no skeptic misconception is as dangerous as this one. Brace yourself . . . Brad is going to start with a premise that you wouldn’t expect here. He grants you that the planet is warming up and (gasp) that humans are likely the dominant reason for it. After you’ve picked yourself up off the floor, you realize that he’s got a zinger for you. There is a school of thought in the skeptic community that climate change is, overall, actually a good thing. All those tree-hugger stories about looming global calamities? Just scare tactics. Now, we’ll grant you that there are folks out there who take things a bit far, sometimes for dramatic effect. Watching Dennis Quaid and Jake Gyllenhaal in The Day After Tomorrow run for their lives from a climatic change that’s moving faster than Usain Bolt may make for a good movie (or not), but that scenario takes more than a little artistic license. Believe it or not, there are indeed some positive effects that are expected thanks to global warming. We’ll go over these in this chapter, but we’ll also cover lots of the negative consequences—and these dwarf the handful of helpful ones. As you’ll see, there is no question that, in the grand scheme of things, climate change is unequivocally bad for humankind. Really bad.
Before we delve into the sorts of things that will happen (or in many cases are already happening) as a result of anthropogenic climate disruption, there are a few general concepts to go over. A key thing to keep in mind when it comes to effects of climate change is that they will all be proportionate to the amount of warming. Each additional degree of warming beyond the baseline global temperature will not only introduce new effects, but it will also make each effect more severe. It may seem that one single, lowly degree shouldn’t even make a difference. Who among us can really tell the difference between, say, seventy-four and seventy-five degrees Fahrenheit? (No doubt some of you are now turning to argue with a significant other or roommate about that thermostat setting in your home.) Surprisingly enough, that one degree really does have a colossal impact on the planet and its inhabitants. This is why it’s so important to limit our impact on the climate as much as possible. We are already at a point where we’ve begun to screw with the system, but that doesn’t mean we’re all doomed. Every bit that we can lessen our greenhouse-gas emissions will make the effects less severe.
Before we send you cowering under your covers and buying emergency kits, let’s be fair to Brad and spend a little time talking about the handful of positive effects anticipated to result from a warming planet. The positive outcome that probably receives the most attention is the fact that the Arctic Ocean’s Northwest Passage will eventually be free of sea ice (at least in the summer months), thereby opening up a shortcut for marine shipping between the Atlantic and Pacific Oceans. Assuming that the passage was safely navigable (a big “if,” since iceberg threats will remain), it would represent a substantial boon for the shipping industry. A related opportunity would be the ability to lay fiber-optic cables under the Arctic Ocean, which could significantly increase global communication speed. Also, there are probably undiscovered natural gas and oil that will become accessible, though of course that’s the stuff that got us into this situation in the first place.
Another consequence of maintaining a relatively cooler climate is pretty straightforward: winter kills. Segments of the population that are especially vulnerable, such as the elderly, can succumb to extreme cold weather; every year there are many thousands of deaths worldwide that are attributed to this phenomenon. If the planet warms, you’d expect to have fewer such deaths.
Beyond these effects, there is only one other major outcome purported to be a good thing to come from climate change. The argument is that global warming is good for agriculture and plants in general. For one thing, some regions will likely have longer growing seasons due to shorter winters (though in many cases, these regions receive little sunlight during the extended season anyway because they’re at high latitude, so the benefits would be minimal). Another aspect related to plants is that plants absorb carbon dioxide. In effect, it is plant food, so more carbon dioxide in the air means plants have more to eat. Sounds like a good thing, right? Well, it isn’t as simple as that.
Brad points out that people have shown that pumping extra CO2 into a greenhouse leads to faster growth of the plants inside. True enough. But hidden in these studies is the fact that these plants have luxurious environments where they receive all the water and nutrients they need to sustain that faster growth, as well as protection from insects. Outside the protective walls of a greenhouse, plants do not necessarily have access to these resources, which means that they may not benefit from having additional food. Water, in particular, is an issue. As the world warms up, evaporation increases, pushing the water needs of plants up even higher. Many agricultural regions are already under water stress, and climate change will have a dramatic impact on not only the demand side but also the supply side of the equation. Even where you might think you’d catch a break, such as in the fact that rainfall is expected to increase in some areas because of stronger storms, in reality these heavy downpours cannot be fully absorbed by farmlands, and the runoff carries away both soil and fertilizer. Agriculture will be hit hard by other factors, too, but let’s get back to the plant-food myth for now.
As scientists have researched the topic of carbon dioxide’s effect on plants with greater rigor, the focus has shifted from greenhouse studies to so-called free-air CO2 enrichment (FACE) studies. In FACE studies, the experiments are conducted outdoors with a carefully controlled release of carbon dioxide, thereby providing a more realistic replication of how plants would react in a real-world setting with a particular concentration of CO2 in the air. The results from this more sophisticated research are far less promising than those from the greenhouse work. The reasons for the disappointing yields, despite the presence of increased food, range from carbon dioxide making the plants more vulnerable to insects, to changes in soil chemistry that render plants more susceptible to disease, to differences in the way roots develop in the two environments (greenhouse vs. outdoors). Another issue is that some staple crops, such as wheat, have less nutritional value when grown with excess CO2, suggesting that even if yields increase, the added nutritional value would be minimal.
OK, so there are in fact a few good things that might happen as a result of climate change, although not as many as claimed by Brad and friends. Now let’s turn our attention to the flip side. Many of the negative impacts revolve around what will happen to animals and plants as the planet heats up. Though it probably irks some of Brad’s like-minded brethren, some of whom, in all likelihood, are also evolution skeptics, he tells you that there’s no reason to fret about all those creatures and plants because they can simply adapt to the changing environment. It turns out that we humans are so adept at messing up ecosystems through centuries’ worth of carelessness (agriculture, mining, logging, overfishing, relocation of species, and so on) that it’s challenging to dissect which impacts can be traced specifically to anthropogenic climate change. Scientists who would be best qualified to figure that kind of thing out, like conservation biologists, are rightfully more focused on all those other shorter-term threats to ecosystems. That said, there have been some important studies looking at the effects of global warming on various species. The upshot is that the pace of climate change spurred by human activity is so fast (and accelerating!) that species are not well equipped to adapt in time.
We are poised to compress an amount of global warming that historically has occurred over the course of thousands of years into a single century. The most optimistic scenarios project about two degrees Celsius of warming this century, which would put us at a temperature last seen during the Pliocene Epoch, about three million years ago. A more realistic number seems to be around four degrees Celsius. While four degrees doesn’t seem like much, you’d have to look back thirty-five million years to find the last time Earth witnessed such a temperature average. That was the Eocene Epoch, and creatures like Campanile giganteum—a sea snail about two feet long—and Gigantophis—a snake more than thirty feet long—were moseying about the planet. Yikes. Those species, like most that were around back then, are gone now (we’ll pause while you sigh in relief). Species generally only stick around for a few million years, though there are plenty of exceptions. The point is that the climate changes that we are in the midst of have never been encountered by most of the species alive on Earth today. Moreover, the stresses caused by climate change are just one part of a collection of stresses caused by human activity, meaning that the buffer for adaptation is basically exhausted already. Will plants and animals be able to adapt, as Brad claims? Perhaps a bit here and there, but in the big picture, the answer is a very unfortunate no. Scientists anticipate extinctions on a frightening scale, with each successive degree of warming adding considerably to the roster of species lost forever. Polar bears are the poster child for this phenomenon, but they are essentially canaries in the coal mine. The effects of climate change are often strongest in polar regions, so the effects there are harbingers of what’s to come for the rest of the planet.
Edited excerpt from How to Change Minds About Our Changing Climate: Let Science Do the Talking Next Time Someone Tries to Tell You the Climate Isn't Changing, Global Warming Is Actually a Good Thing, Climate Change Is Natural, Not Man-Made and Other Arguments It's Time to End for Good, Copyright © Seth B. Darling and Douglas L. Sisterson, 2014. Reprinted by permission of the publisher, The Experiment. Available wherever books are sold.