Science Technology Fact or Fiction? 7 Eco-Myths Debunked By Shea Gunther Writer University of New Hampshire Rochester Institute of Technology University of Southern Maine Shea Gunther is a writer, entrepreneur, and podcaster living in Portland, Maine. He covers topics such as renewable energy, climate change, and nature. our editorial process Shea Gunther Updated October 24, 2019 Share Twitter Pinterest Email Science Space Natural Science Technology Agriculture Energy Spreads like wildfire antipathique/Shutterstock. Mythology can be a powerful thing. Humans have been telling stories since the cave days, and as technology has advanced so has our ability to share our tales. In today's world, we're faced with a glut of information. Stories and narratives help us piece it all together. Sometimes the stories we share are factual, and sometimes they are outright wrong; more often, they fall somewhere in between. Here's the truth about seven green myths. (Text: Shea Gunther) Local food is always better Natalie Maynor/Flickr. "Buy local!" the stickers yell. The local shops in my town sport that message everywhere; your town probably does, too. The buy local movement is a strong current in the river of environmentalism, and for a good reason: It does make good sense to keep your money and shopping close to home ... but not always. Local food isn't always better. There are many things you have to consider when assessing the environmental impact of a food item. Besides just how far it traveled from field to market, consider how the food was harvested, processed, stored and transported. For example: New Zealand farmers use a lot of renewable energy and less fertilizers, so it's actually less CO2-intensive for U.K. citizens to import lamb than to buy the local variety. Local is important, but it's not everything. Do your homework. Small farms are good; big farms are evil Puncusvt/Flickr. The conventional green wisdom on farms is smaller is better. We've been told repeatedly by passionate activists and persuasive literature that smaller, independent farms are preferable to those owned by giant corporations, but is that sentiment always true? Not always. Occasionally big farms are better than the little guy. Freelance journalist Tracie McMillan found that some workers prefer the benefits and consistency of a larger operation. Big farms are also more likely to be visited by government inspectors, and there is something to be said for the efficiency gained from a large-scale operation. We certainly need to support small farms, but we shouldn't dismiss all big farms as evil. CFLs, incandescents and mercury Anton Fomkin/Flickr. Compact florescent lights or CFLs require mercury to operate. The mercury gas contained within the tube gets excited when electricity is passed through it and emits UV light which excites the coating of phosphor lining the tube, generating light. Though manufacturers have been making steady progress on the amount of mercury required for CFL bulbs, most on the market still contain the deadly toxin. Because of this, it might be easy to favor the incandescent bulb which contains no mercury. But consider this: the source of most of America's electricity, burning coal, releases lots of mercury into the atmosphere. The mercury generated from the extra electricity needed over the lifetime of an incandescent bulb is far more than the amount found in your average CFL bulb. All invasive species are bad SoftCore Studios/Flickr. We've talked about invasive species a lot on MNN, and most of the time the stories highlight the resulting problems. For example, rabbits, cane toads and camels introduced by early settlers are wreaking havoc on the ecology of Australia. The Great Lakes are under siege from zebra mussels. Florida wildlife officials are battling non-native Burmese pythons. Anytime an exotic animal is brought into a new environment, it frequently ends badly, but there are some places where that's not the case. In Hawaii, non-native birds are helping native shrubbery to survive. In the Southwestern U.S., typically invasive kudzu is helping a native bird dodge extinction. Rebecca Tuhus-Dubrow, a writer for Slate, uncovered many examples of foreign plants and animals being a good thing. The rain forest is a natural phenomenon Butch Osborne/Flickr. In 2003, writer Charles C. Mann wrote an article in The Atlantic (later to be turned into a book) that posited a startling idea — that the Amazon rain forest, far from being a natural phenomenon, was a purposefully engineered tree farm planted by humans thousands of years ago. Rogue archaeologists Clark Erickson and William Balée believe the North and South American continents were populated by large and advanced civilizations that pulled off enormous feats of geoengineering, and the rain forest is a result of hundreds of years of fruit and nut tree cultivation by farmers. If we planted it once, that would mean we could plant it again. The more trees, the better Lincolnian/Flickr. In the U.S., the last Friday of April is Arbor Day. The holiday is celebrated in 32 countries at different times of the year, and it's a great excuse to plant some new trees. Everyone loves trees. They're great for climbing, lounging under, swinging from. They provide shade, beautiful leaves in autumn, and they absorb CO2 and create oxygen. The more trees, the better, right? Not always. While trees provide many great benefits, some species require a lot of water to grow. The wrong kind of tree planted in the wrong place can trim the amount of water reaching the water table and increase its salinity. Diversity is also important. Monoculture forests are susceptible to disease than natural and mixed-species forests. A hybrid car is always the best choice Photo: By otomobil/Shutterstock "South Park" got a lot of laughs from hybrid car owners (and others) in an episode called "Smug Alert!" based on the smugness that seems to ooze from a newly minted hybrid owner. There's no dispute that hybrid cars use gas more efficiently, but is a hybrid the best choice for everyone (and the planet) every time? When you consider the amount of energy that goes into making a new car, it may make sense, financially and environmentally, to purchase a used conventionally powered car. Diesel engines have made big leaps in reliability, performance and economy, and can also be a better choice than a hybird for the pocketbook and Mother Nature. Ecologically smart car shoppers should study all their options before signing on the dotted line.