As I write this, the disaster of Hurricane Harvey is still unfolding. Buckets of rain are still falling in Houston and the waters are still rising. The flood damage, biblical in proportion, is frightening to behold. Even as the rescue efforts continue, many are wondering, “Is this the new normal for our coastal cities?”
As Earth’s climate changes we can expect more destructive hurricanes. As sea level and surface temperatures rise, more solar energy is trapped in the atmosphere, revving up the hydrological cycle of evaporation and precipitation, and sometimes manifesting in terrifying storms. Add to this the rapid and sometimes careless development of our urban areas in patterns which are, shall we say, not always strictly motivated by long-term planning for runoff management and neighborhood safety.
In all these ways this disaster reflects changing circumstances in this new time of enhanced human influence which many are calling the Anthropocene—the geological age of humans. With this title we recognize that we have become a planetary-scale force.
Some developments of the Anthropocene are cause for celebration. Consider the fleet of Earth-observing satellites that we now take largely for granted. Scientists and historians have not agreed on a start date of the Anthropocene, but one candidate might be the moment in the late 1950s when Earth began launching small metallic pieces of itself back out into the void. The first successful weather satellite, TIROS-1, was launched in 1960 and returned the first television image of Earth from space. Since 1962, we’ve had continuous satellite coverage of Earth’s weather patterns. Our planet had entered a new phase—it had begun to self-monitor.
Before the 1960s, we had only a vague idea of what a hurricane looked like. Today, even the smallest tropical storm will be noticed and intensely scrutinized, modeled and forecast as soon as, or sometimes even before, it forms. Most of us experience hurricanes as immense magnificent swirls on the map that sweep across the ocean, their menacing arms swiping at our coastlines, their central eyes sometimes making landfall, to devastating effect. On the ground, those in the path experience them as fearsome torrents of wind and rain. Thanks to the quotidian experience of TV weather reports, in little over a generation we’ve internalized and integrated this bizarre Anthropocene abstraction, leaping mentally between grounded experience and orbital views of our weather systems.
Our planet has grown a new sensory organ, a diffuse and orbital mycelium of detectors, radio transmissions, and microprocessors. Instantaneous global views are available from anywhere and, together with models run on supercomputers, they give us unprecedented foresight into the immediate future. Our continuous record of seasonally changing landscapes and roiling weather patterns reveal previously hidden patterns that aid disaster response, and the global web of communication satellites insures that this information is available to a large and growing portion of Earth’s inhabitants.
Now we see storms coming. Governments have a chance to shore up resources and defenses, to warn or evacuate. Institutions have a chance to prepare and make contingency plans, and residents have more chance to leave, to stock up, or to fortify.
Hurricane Harvey is showing us both the benefits and the limits of our ability to predict storms and act on our foresight. A major rainfall event was predicted many days in advance but with cruel timing the storm strengthened just before making landfall and then stalled out, gushing colossal amounts of water over a heavily populated region with poor drainage. Decisions about evacuations will be analyzed and second-guessed for years. The city will sustain considerable damage. Yet imagine how vulnerable a modern city like Houston or New Orleans would be without our satellite eyes and computerized warning systems.
On September 8, 1900, a Category 4 hurricane slammed into the gulf coast of Texas. Back then, nobody saw it coming. (There were some warnings from Cuba, where the storm had passed through, but these were ignored.) The residents of Galveston were helpless, with no chance to evacuate or prepare. Something like 20 percent of the population was washed away. An estimated 8,000 people perished. It was the deadliest natural disaster in U.S. history. As long as we retain our capacity for vigilant satellite monitoring, we will never suffer that magnitude of loss from another storm. This illustrates an Anthropocene paradox: Our technological interventions both endanger us and come to our rescue. Even as our unwitting alterations to Earth’s carbon and hydrological cycles slowly make storms more damaging, our ability to monitor our planet from space and make reliable short-term forecasts have equipped us enormously to withstand them.
Humans are possessed, to some degree, with the power of foresight. Yet we so often learn things the hard way, through disaster. In addition to tracking storms, Earth observations also reveal to us a planet with warming temperatures, disappearing glaciers, and declining arctic sea ice.
As a child I was enthralled by the Apollo astronauts based in Houston, whose exploits inspired me to study climate change on Earth and other planets. Through space-based climate studies my colleagues and I have learned that a stable and comfortable climate is not something to take for granted. We know that we humans must rapidly change our energy supply, or suffer more and more devastating heat waves, droughts, floods and storms. If we take the slow road to our inevitable non-carbon energy future, these changes may also bring wars, famines, and displaced peoples. We need a rapid transformation in our energy systems and our urban-planning paradigms so that Hurricane Harvey does not become an emblematic 21st-century experience.