Manabe and Hasselmann share half the Prize “for the physical modelling of Earth’s climate, quantifying variability and reliably predicting global warming,” while the other half went to Parisi “for the discovery of the interplay of disorder and fluctuations in physical systems from atomic to planetary scales.”
In more simple terms, what the new Laureates are being honored for is developing methods to understand complicated physical systems. And winning this award reaffirms what should be accepted science: The phenomena driving climate change is well known. It’s basic physics, albeit playing out in the ever-changing atmosphere.
Big picture, the conversation should no longer be on debating the science itself, but rather on deciding what society should do about it.
Complex systems involve the interplay of lots of variables, where the individual variables can affect one another. An example might be how the amount of incoming sunlight affects the temperature measured at the Earth’s surface. More sunlight will make the air hotter, which will increase evaporation from lakes and ponds. This process will produce clouds, which will reflect away sunlight, thus reducing the temperature. In this example, the sunlight, humidity, availability of surface water, and air temperature all dance to an intertwined and tumultuous tune.
Manabe’s work in the 1960s led to the development of early climate models, which have been refined and improved over the past half-century. He studied the crucial relationship between the amount of carbon dioxide in the atmosphere and the Earth’s temperature, showing that it was carbon dioxide levels — and not sunlight — that more dominantly affect the Earth’s average temperature.
Hasselmann’s work was published a decade later and modeled the differences between climate and weather. Weather is chaotic and variable and can change day to day, while climate is slow and gradual and predictable. Hasselmann’s models distinguish between man-made perturbations on the climate and natural ones. His methodology also very clearly points toward the effect humans have on the Earth’s temperature.
Parisi’s work, on the other hand, was motivated by very different questions. He was interested in finding patterns among the chaos. He developed techniques that he then used in the study of metal alloys with unusual magnetic properties. The techniques were then generalized to a variety of other fields, ranging from biological systems to very complicated materials, and yes, to modeling climate change.
One application of his work is to understand patterns in how the Earth’s climate changes over time, oscillating from warm periods to ice ages. Over the last 2.6 million years, the climate has swung from hot to cold like a chaotic pendulum. Parisi’s mathematical modeling is ideal for investigating what variation is mere chaos and what has larger causes.
Just because these three men have won a Nobel doesn’t mean that scientists won’t continue to discuss the finer points of atmospheric science. They will. But the broad strokes are very clear — and this means we should no longer be having conversations about whether climate change is real.
Instead, the conversation should be on what to do about it. And there the answers are thornier. While scientists can very clearly demonstrate what is going on, theirs should not be the only voices contributing to this conversation. Experts of all backgrounds should be heard, from industrialists to politicians to environmentalists.
Should we invest in green energy? Nuclear power? Should politicians offer tax credits aimed at encouraging conservation? How do we balance the striking economic disparity that exists between developed countries and those that are still developing? What about carbon mitigation strategies, including technologies that draw carbon dioxide out of the atmosphere and sequester it deep underground?
Each approach to these questions has costs and benefits. Some are more effective than others, while others appear attractive but will not have a big impact on the problem. Personally, I favor a tax structure on carbon fuels that reflects the costs of a warming planet.
If governments will help rebuild communities devastated by more violent hurricanes, prolonged droughts, rising sea levels and famine in parts of the world, mitigating these events will all cost an enormous amount of money. Rather than a general increase in taxation or public debt, attach those costs to the cause. When the price of fossil fuels reflects the true cost to societies around the world, I trust the free market to develop solutions to our energy needs that don’t have such expensive consequences.
On the other hand, I’m a research scientist, not an economist, nor someone with real responsibility for the livelihoods of citizens of the world. I’m not claiming that my proposal will solve all problems. It may even be a very bad idea for very valid reasons.
But the conversation on climate change should proceed in this direction and not pursue the already resolved question of whether the science is real. Experts have long understood the strength of the scientific case, and it is high time that the Swedish Academy recognized these three gifted thinkers for their contributions to understanding it all.
Congratulations new Laureates!