The Science of Climate Change

Summary: Michael Oppenheimer and Jesse Anttila-Hughes begin with a primer on how the greenhouse effect works, how we know that Earth is rapidly getting warmer, and how we know that the recent warming is caused by human activity. They explain the sources of scientific knowledge about climate change as well as the basis for the models scientists use to predict how the climate will behave in the future. Although they acknowledge the large degree of uncertainty that surrounds predictions of what will happen decades or even centuries in the future, they also emphasize the near certainty that climate change has the potential to be extremely harmful to children. Most children around the world will face hotter, more extreme temperatures more frequently. Higher temperatures will directly affect children’s health by increasing the rates of heatstroke, heat exhaustion, and heat-related mortality. Excessive heat is also likely to affect children indirectly by disrupting agricultural systems, driving up prices, and increasing food scarcity. Many of the world’s children may see local demand for water outstrip supply, as shifting precipitation patterns dry out some regions of the world, make other regions wetter, and increase the frequency of both unusually dry periods and unusually severe rains. Mountain glaciers will recede further, significantly reducing storage of winter snows and thus springtime runoff, which has traditionally been used to water fields and recharge reservoirs. Melting ice will also raise sea levels, triggering direct physical threats to children through flooding and erosion and indirect threats through migration and expensive adaptation. Climate change is also expected to make weather-based disasters more frequent and more damaging. This is particularly worrisome for children, not only because of the physical peril disasters pose but also because disasters can have debilitating long-term indirect effects on children. Damage to ecosystems from climate change may also harm children; for example, acidification the world’s oceans will reduce food supplies, and disease-carrying insects will invade new areas in response to changing rains and temperatures. In the face of such dire forecasts, Oppenheimer and Anttila-Hughes argue, climate change forces us to directly confront the value we put on future children’s wellbeing. Fortunately, we have reason for hope as well as for concern: “History,” they write, “has demonstrated time and again that humans can tackle uncertain threats in times of need.”