People always ask Hope Jahren why she doesn’t study the ocean, since she lives in Hawaii. She responds that the ocean is a lonely place, while land is much more lively: the lifespan of the average ocean plant is 20 days, while the average plant on land has a lifespan of over 100 years. There are 200 trees to every person, and once Jahren discovered this, plant life is all she can see.
In this memoir, Hope Jahren interweaves her personal story with the story of plant life, which is her passion and line of work. She wants to share that passion with her readers, just as she does with the students she teaches, and she begins by illustrating how prevalent plant life is on the planet.
Jahren then asks readers to look out their windows, asking them what they see. Most people first focus on things that people make, like buildings and vehicles. Look again, she urges—look for something green, something that people did not make: plants began to populate the earth over 400 million years ago, well before humans. Now, Jahren continues, focus on a single leaf. A leaf is something that humans do not know how to create, but they sure know how to destroy. Jahren points out that every 10 years, humans have cut down forest areas approximately the size of France, over and over, throughout history. No one seems to care about this, but everyone should care, she argues, because these are unnecessary deaths.
Jahren moves on to the topic of conservation, because while plant life is abundant on Earth, human activity and heavy industry are decimating it, which is of serious concern to her as a plant biologist. She personifies plants throughout the memoir for two reasons: first of all, because she feels a personal and emotional connection to them, and secondly, because she knows that if her readers think about plants as similar to humans, they will care more about their destruction and possibly take action.
Jahren looks at a lot of leaves, and asks a lot of questions about them. She analyzes color, shape, size, texture, relationship between the leaf and the stem, and many other variables. She then urges readers to look at their leaf and ask some of the same questions. And with that, she pronounces, “you are now a scientist.” Jahren disagrees with those who demand that people must know math, physics, or chemistry to consider themselves scientists. To her, that is like making knitting a requirement to be a housewife, or knowledge of Latin for biblical study. Math, physics, and chemistry are helpful, but the foundation of science is observation and asking questions. And now that the readers are scientists, Jahren prepares to tell her story, “one scientist to another.”
Jahren is also focused on making sure that her readers, and the public in general, do not fall prey to the myth that scientists are a group of superhuman beings or that the work she does is out of reach. Not only does she promote the image of women in science, she suggests to her readers—male and female—that they can consider themselves scientists based on their activities, like asking questions about the things they see around them. While she notes that formal study is “helpful,” she defines a scientist by his or her ability to express curiosity about the world.