speciated over the last 2 million years, during which the planet was deep in an ice age more than 90% of the time. Physiologically, ecologically, and in many ways, behaviorally, we are an Ice Age species. This transition from a glacial to interglacial world is continuing today and we can see real-time evidence in the form of yearly shoreline retreat in places like Scandinavia, where the land is literally bouncing skyward in response to the unloading of glacial ice. Yet the modern natural changes are now overshadowed by much more rapid human-induced changes to the landscape as we enter a planetary greenhouse epoch. Once again, time is the big discriminator between natural and human- attributed impacts. The changes being wrought on Earth’s lands and seas today through human-induced climate change and resource utilization are occurring at rates that are 10 to a thousand times more rapid than what nature does on its own. Herein lies the existential nature of the crisis. As a species, we are inherently challenged to com- prehend natural planetary changes at timescales longer than a generation. How can we conceive of much more rapid changes in our greenhouse future — to the point where we share newfound, widespread, and shared motivations to change course? In my work, I publish scientific papers that use time to tell stories of sudden climate surprises and impacts that happened in the past, using geological and biological indicators. My work consists of journeys that overlap in time, some lasting decades; my portfolio reflects progres- sion towards increased understandings and discoveries of new complexities that can only come from repeated visits to the wilderness. Yet my work mainly reaches and influ- ences other scientists and some policy-makers. We desperately need to convey stories of nature, time, climate, and dynamic transitions through other media. I’ve had the pleasure of viewing most of Tony’s watercolor work, spanning his many Journeys. I was drawn to Tony’s art area through the lens of expeditionary and observational research wherein my field notebooks and digital data sets take the place of Tony’s watercolors. Whenever I start a new research journey to an untouched place, such as the deep sea, Antarctica, or an uninhabited coral atoll, or a coupled human-natural system in the Andes, Himalayas, or Africa, I ALWAYS start with questions of time. How did a place come to look the way it does? Where might we see it changing at this very moment? How long have people lived there and what is the balance of adaptation to place versus modification of and efforts to control nature? My geologic training lets me visualize centuries to millions of years of change and my ecological interests connect across many timescales to even the month-long lifespans of single-celled marine plants that produce half the oxygen we breathe. Any snapshot view of our planet today reflects the interplay of myriad physical, climatic, and biologic processes operating over vastly different timescales. Even small, often climatically-driven changes in any of these processes, including the residential biota, can trigger wholesale reconfigurations of ecosystems and habitats. For example, during the last Great Ice Age, ending only about 11,700 years ago, the big ice sheets and ice caps on Earth were 3 times larger than they are today and sea level was nearly 400 feet lower, extending conti- nental margins far out to sea. The ice sheets were so tall that they deflected the atmospheric jet streams that influence storm tracks, temperatures, and rainfall world- wide. The world was a very different place and the ride out of the glacial age to today’s climate was both rough and full of surprises. Deep canyons formed where rivers flowed across vast coastal plains, retreating glaciers left behind cirques, glacial lakes, and massive outwash plains and moraines, and the Sahara Desert shrank dramatically, allowing the return of Sahelian and subtropical vegetation. Although human societies evolved during this transition out of the Ice Age, as a species we evolved entirely during the planetary icehouse. Like the bluefin tuna, hominids BIOLOGICAL TIME Tony’s 19th Journey, Exploring Time: A Painter’s Perspective Rob Dunbar W.M. KECK PROFESSOR EARTH AND OCEAN SCIENCE SENIOR FELLOW AT THE WOODS INSTITUTE FOR THE ENVIRONMENT DOERR SCHOOL OF SUSTAINABILITY, STANFORD UNIVERSITY Like Tony, I’ve spent much of my career living and working in wilderness areas, at both poles and throughout Earth’s oceans. I’ve enjoyed many conversations with Tony over the past 20 years and am struck by how many times our paths have literally crossed, albeit asynchronously, in pristine mountain belts, canyon lands, forests, and coral reefs. I relate to Tony’s journeys through time and place because I think the same way about my own journeys of exploration into the ecologic, geologic, and climatic drivers that shape our planet and exert strong controls over how the human enterprise intersects with nature. My first real journey began more than 50 years ago on my first oceanographic expedition to the Gulf of Mexico, where I collected sediment samples from the seafloor to under- stand how storms were changing the Texas Barrier Islands. Strolling on these lovely beaches on a calm and warm day, with seabirds nesting amongst adjacent dune grasses, it is easy to view such scenes as stable and long-lived. Yet when read correctly, the accumulating sediments tell a different story, one of epic changes in the shape, volume, and location of Texas’s coastal islands, estuaries, and bays, all at timescales that are just beyond our societal grasp. I find these changes in landscapes and seascapes, their causes, their impacts on life, and how we perceive and adapt to them utterly fascinating. I’ve explored this rich subject 98
