Mark Serreze: The Value of Climate Science

 

Modern climate science is based on facts, physics and testable hypotheses. There is ample room for debate about what to do about climate change, but the underlying science is rock solid.

Modern climate science builds on a long track record of scientific inquiry on environmental and health issues that has benefited society. Through scientific analysis, it was discovered that DDT, widely used as a pesticide, was becoming concentrated in the food chain. As a result, laws were passed to curb its use. Tetraethyl lead was once added to gasoline to reduce engine knock. Through science, we learned that lead in the environment poses severe health hazards, so the use of lead in gasoline was consequently phased out. It was through science that we learned how CFCs were destroying stratosphere ozone. In turn, through many decades of research, we have developed a strong understanding of how the climate system works, how humans are affecting climate, and what is in store if society continues to follow its current path without taking corrective action.

Until the middle off the 20th century, climate science was pretty much a backwater. Climatologists, by and large, were bookkeepers, compiling records of temperature, precipitation and other variables. From these records, much effort was spent classifying climate types around the world, ranging from tropical rain forests to monsoons to semiarid steppes to deserts. Climate data certainly had value to farmers and the home gardener, civil and structural engineers and the military planning. But the focus was largely on statistics, with relatively little emphasis on climate dynamics – the processes that control the climate system and how it may evolve. There were notable exceptions, such as Svante Arrhenius, who, in the late 19th century, speculated on how rising concentrations of carbon dioxide would lead to warming, but for the most part, climatology was a largely descriptive and rather boring field of science.

The shift from simple bookkeeping to a more physically-based view of how the climate system works paralleled developments in meteorology—the science of weather prediction. The rapid advances in meteorology following the Second World War, in turn, largely paralleled the development of numerical computers. With computers, it became possible to translate the physical processes controlling weather systems into computer code. It was readily understood that the physics controlling weather were part of the broader set of physics that control climate, which led to the development of global climate models, or GCMs for short. GCMs were quickly seen as powerful tools to understand not just how the global climate system works, but how climate could change in response to things like brightening the sun or altering the level of greenhouse gases in the atmosphere.

Using early generation GCMs developed in the 1970, pioneers like Jim Hansen of NASA, and Suki Manabe of the Geophysical Fluid Dynamics Laboratory in Princeton confidently predicted that our planet was going to warm up, and that the Arctic would warm up the most, something that we now call Arctic amplification. But the more mundane chore of compiling climate records never stopped, and indeed, its value grew, for it was only with ever-lengthening climate records that it could be determined if things were actually changing. And as these records grew, it slowly became clear that the planet was indeed warming. From numerous GCM experiments, it also became clear that this warming, and all the things that go with it, such as the Arctic’s shrinking sea ice cover and Artic amplification, could only be explained as a response to rising levels of carbon dioxide in the atmosphere.

Climate scientists of today need to know:

  • The processes that can change how the earth absorbs and emits energy
  • How the atmosphere and weather systems work
  • How the atmosphere interacts with the oceans
  • How the atmosphere interacts with the land surface
  • And how the land interactions with the ocean.

But whatever our area of specialty, we all try and make contributions to our understanding, but those contributions are, to the best of our ability, based on facts, physics, and sound methodology. In science, there is no room for wishful thinking. As a society, need to get past partisan bickering, step back, and listen to what climate science is telling us: the climate is changing, we know why, and the implications must not be ignored. This is the value of climate science.

Mark C. Serreze is director of the National Snow and Ice Data Center, professor of geography, and a fellow of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado at Boulder. He is the coauthor of The Arctic Climate System. He lives in Boulder, Colorado.

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