INTRODUCTION Ecological Thinking and You Whitney: There we were, exploring a place we''ll call Redwood Adventure Park, a nature attraction in Northern California. It was 2003, and my parents and teenage brother and sister were visiting during my first year of college. We''d decided to drive along the coast and visit every Highway 101 pit stop we could find. Road sign after road sign pointed us to this particular adventure, so five twenty-dollar tickets later, we were in weird redwood heaven. Wooden placards gave background stories on all the trees, and there were carved stumps--of woodland creatures, loggers, and Bigfoot--everywhere. A few months earlier, I''d given myself a buzz cut and dyed my naturally blondish hair black for "I''ll show you, world" reasons. It had grown out into an unruly mullet and was flopping around mop-like as I scampered among the living and carved-up trees, giggling at what could only be described as forest clickbait. After wandering the park''s crisscrossing trails, we decided to head over to the forest ridge lookout for a bird''s-eye view of the canopy.

At the top of a seemingly endless flight of stairs, a worker wearing head-to-toe pink camouflage ushered us onto the viewing platform, gestured around dramatically, and told us in a hushed voice that on one side we''d see the ocean and on the other, "the Awesomeness," which I think just meant more trees. But before we could climb to the top, my sister needed to finish drinking her hot chocolate. "''Kay, ready," she said when she was finished. She handed her empty cup to my mom, who held it for a moment. Then, looking right at my sister, my mom threw the cup smack on the ground. We all paused. Gasped! Why would she do such a thing? And then my mom started laughing. She bent down to pick up the cup.

"The look on your faces!" she said, still laughing. We all started laughing too, and then, of course, as soon as we saw a trash can, she threw the cup away. This was funny because, for one thing, it was so unexpected. I''d never seen my mom litter in my whole life. It was also funny because it was exactly what you''re not supposed to do at a park. If you did, you''d have to walk around in your own mess. Other people would have to walk around in it too, and some of them might get the idea that hey, fun, it''s fine to throw trash here , making it more likely that more people would throw their trash wherever. From there, it could end up in a river or be swallowed by a goose.

The moral of the story, said in my best judgmental Bigfoot voice, is that throwing your trash on the ground when you''re at a park doesn''t just impact you. It impacts others as well, Mom. RYAN: Trash, or at least stuff you don''t want to have to walk through, is a theme in this book. But instead of actual dirty cups on the ground, we''re focused on information pollution. Here''s an example from one of my communication classes. I live in Charleston, South Carolina, and we get a lot of hurricanes. That means a lot of rain. After Hurricane Matthew flooded parts of the city in 2016, one of my students brought in a picture of a shark swimming around in someone''s front yard.

He was showing it to other students before class, telling us all to watch out for sharks if we were walking through flooded streets. As the old-man media professor and multiple-hurricane survivor in the room, I had the sad duty of telling my student that his shark picture was an obvious fake; I''d seen it passed around the internet for years . The real reason not to splash around in urban floodwater, I explained, is that it comes up from the sewer. And sewer water is treacherous enough without sharks sloshing through it. My student glared at me and then at his phone and then sat down. "But my friend sent this to me," he insisted. And maybe his friend was just trying to be helpful. That still does not a yard shark make.

WHITNEY: Here''s another example a student shared in one of my media literacy classes. This student had a close girlfriend group, and they were constantly posting photos to Instagram of parties and other college whatnot. One friend only posted photos where she looked good, even if the other friends in the pictures were sneezing or seemed constipated, which the rest of the group noticed and giggled about among themselves but never mentioned to their friend. One day, the friend posted a group photo to Instagram that she''d photoshopped to make herself look thinner. The whole image--and her friends'' bodies--had been distorted as a result, making her edit and her motives, let''s say, obvious. My student had been in that picture and admitted to downloading it and sending it to her other girlfriends over group chat. They thought it was hilarious. So hilarious, in fact, that someone in the chat also downloaded the image and posted it to another chat, which made that group laugh too, until eventually the image circulated back to the friend who''d posted it.

She was horrified to find out that everyone had been laughing at her behind her back, and her friends were horrified to realize how upset she was. Even though they didn''t mean any harm, the entire friend group had to deal with the fallout. RYAN: Both stories are examples of information pollution, which can take the form of polluted information and polluting information. In the yard-shark story, the information is polluted. This is the more obvious type of information pollution, and you may have heard it described as misinformation (false or misleading information spread by accident) or disinformation (false or misleading information spread on purpose). When talking about mis- and disinformation, a person''s motives for sharing matter; you need to know why someone shared something to accurately describe it. Polluted information, on the other hand, doesn''t need you to know whether something was spread on purpose or by accident. It all ends up in the same goose.