A New Dark Age Looms

William B. Gail in the New York Times: “Imagine a future in which humanity’s accumulated wisdom about Earth — our vast experience with weather trends, fish spawning and migration patterns, plant pollination and much more — turns increasingly obsolete. As each decade passes, knowledge of Earth’s past becomes progressively less effective as a guide to the future. Civilization enters a dark age in its practical understanding of our planet.

To comprehend how this could occur, picture yourself in our grandchildren’s time, a century hence. Significant global warming has occurred, as scientists predicted. Nature’s longstanding, repeatable patterns — relied on for millenniums by humanity to plan everything from infrastructure to agriculture — are no longer so reliable. Cycles that have been largely unwavering during modern human history are disrupted by substantial changes in temperature and precipitation….

Our foundation of Earth knowledge, largely derived from historically observed patterns, has been central to society’s progress. Early cultures kept track of nature’s ebb and flow, passing improved knowledge about hunting and agriculture to each new generation. Science has accelerated this learning process through advanced observation methods and pattern discovery techniques. These allow us to anticipate the future with a consistency unimaginable to our ancestors.

But as Earth warms, our historical understanding will turn obsolete faster than we can replace it with new knowledge. Some patterns will change significantly; others will be largely unaffected, though it will be difficult to say what will change, by how much, and when.

The list of possible disruptions is long and alarming. We could see changes to the prevalence of crop and human pests, like locust plagues set off by drought conditions; forest fire frequency; the dynamics of the predator-prey food chain; the identification and productivity of reliably arable land, and the predictability of agriculture output.

Historians of the next century will grasp the importance of this decline in our ability to predict the future. They may mark the coming decades of this century as the period during which humanity, despite rapid technological and scientific advances, achieved “peak knowledge” about the planet it occupies. They will note that many decades may pass before society again attains the same level.

One exception to this pattern-based knowledge is the weather, whose underlying physics governs how the atmosphere moves and adjusts. Because we understand the physics, we can replicate the atmosphere with computer models. Monitoring by weather stations and satellites provides the starting point for the models, which compute a forecast for how the weather will evolve. Today, forecast accuracy based on such models is generally good out to a week, sometimes even two.

But farmers need to think a season or more ahead. So do infrastructure planners as they design new energy and water systems. It may be feasible to develop the science and make the observations necessary to forecast weather a month or even a season in advance. We are also coming to understand enough of the physics to make useful global and regional climate projections a decade or more ahead.

The intermediate time period is our big challenge. Without substantial scientific breakthroughs, we will remain reliant on pattern-based methods for time periods between a month and a decade. … Our best knowledge is built on what we have seen in the past, like how fish populations respond to El Niño’s cycle. Climate change will further undermine our already limited ability to make these predictions. Anticipating ocean resources from one year to the next will become harder.

Civilization’s understanding of Earth has expanded enormously in recent decades, making humanity safer and more prosperous. As the patterns that we have come to expect are disrupted by warming temperatures, we will face huge challenges feeding a growing population and prospering within our planet’s finite resources. New developments in science offer our best hope for keeping up, but this is by no means guaranteed….(More)”