Isaac Held (Ulm, Germany; 1948) graduated in Physics from the State University of New York at Stony Brook. He then moved on to Princeton where he obtained his PhD in atmospheric and oceanic sciences in 1976. After being Research Fellow in Harvard University (1976-78), in 1978 he joined the Geophysical Fluid Dynamic Laboratory at NOAA , where he remains to this day, combining his research work with the teaching of classes at Princeton University.
He is Fellow of the National Academy of Sciences, the American Geophysical Union and the American Meteorological Society. He was awarded the Meisinger Award (1987) and the Rossby Medal (2008) by this institution. He has also received the Rosenstiel Award by the University of Miami (1994) and the NOAA Presidential Rank Award (2005).
In over three decades of research, he had published 130 widely cited papers on atmospheric dynamics and climate change. As well as contributing substantially to the Fourth Assessment Report of the IPCC (Intergovernmental Panel on Climate Change), he has served on the World Meteorological Organization Expert Team on Hurricanes and Climate.
Speech
Climate Change, 4th edition
Earth’s surface has warmed by almost one degree in less than a century, due to increased greenhouse gas emissions from the burning of fossil fuels. What consequences will this have for our planet? How will it alter the map of climate zones and with what effects on their inhabitants? The research done by Isaac Meyer Held, an American physicist of German origin employed at the Geophysical Fluid Dynamics Laboratory of the United States National Oceanic and Atmospheric Administration (NOAA), can guide us some way to the answers. Held has earned the BBVA Foundation Frontiers of Knowledge Award in the Climate Change category for uncovering many of the processes that dictate the existence of climate zones, and predicting how they will change in future.
Isaac Meyer Held has opened up new avenues of interest that examine the essential role of water, both by studying its movement in the atmosphere and by investigating how water vapor influences the green-house effect. The jury’s citation mentioned in particular “his fundamental and pioneering contributions to our understanding of the structure of atmospheric circulation systems and the role of water vapor – the most important greenhouse gas – in climate change.”
As Held explains it, “the amount of water in the atmosphere is what makes some zones wetter than others. Trying to understand how water moves in the atmosphere and how climate change may alter those patterns is one of the things I have focused on in my research.
“The amount of water in the atmosphere is what makes some zones wetter than others. Trying to understand how water moves in the atmosphere and how climate change may alter those patterns is one of the things I have focused on in my research.
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I have tried to improve our projections for how rainfall patterns, tropical cyclones, and other complex atmospheric phenomena will change as our planet warms.”
As temperature rises, so too will the quantity of water vapor in the atmosphere, and this gas, in turn, will drive further warming. The result is a positive feedback that will have to be factored into estimates of future climate. Among Held’s own predictions – one that is borne out by available data – is that “wet areas will get wetter, and dry areas will get drier.”
Held’s research holds out a particular warning for the Mediterranean region: “We expect a gradual reduction in rainfall across the area as the climate warms. We are talking about a reduction of roughly 5%, or perhaps even 10%, for every one degree of warming. Our confidence in this projection has increased over time with our improved understanding of the underlying mechanisms, thanks to climate models.”
While recognizing “the importance of this subject for the lives of many people in the future,” which undoubtedly gives it a political dimension, Held admits to a degree of personal discomfort with the public attention garnered by his work: “Researching in climate change is a bit like living in a fishbowl.” As a scientist more concerned about basic research than activism, he feels “it is important for some of us to stay focused on the foundations.”
Isaac Meyer Held was born in a refugee camp in Ulm (Germany). At the age of four, he moved to the United States with his brother, his mother – an Auschwitz survivor – and his father, who died in 1956. The young Isaac was keen on physics and mathematics. As a student, his first choice was theoretical physics, but these were the years of the anti-Vietnam war protests, when, as Held puts it, “it wasn’t that easy to concentrate on one’s studies.”
His watershed moment came in 1972 on reading Man’s Impact on the Climate, one of the first scientific assessments of the effects of rising greenhouse gases in the Earth’s atmosphere. By the time he had finished Held was clear that “this was a challenging problem of real importance to society.”
After graduating in physics from the State University of New York at Stony Brook, he moved on to Princeton where he obtained his PhD in Atmospheric and Oceanic Sciences in 1976. Two years later, he joined the NOAA Geophysical Fluid Dynamics Laboratory, where he remains to this day, combining his research work with teaching class at Princeton University.
One of his first achievements, in the 1980s, was to elucidate the workings of the atmospheric Hadley cell, which governs climate in the planet’s tropical and subtropical belts. Held then went on to investigate how climate change-induced alterations of air circulation in these regions affect the formation of storms and hurricanes. Held is also widely esteemed for his work on testing the reliability of climate change prediction models. His accomplishments “have been pivotal in understanding tropical circulations and climate patterns and in assessing the robustness and limitations of complex models used to predict climate change,” in the opinion of the prize jury.
On this point, Held is generally optimistic: “Computer power has increased dramatically, which allows us to simulate the climate while making fewer assumptions and to try out more ideas.” This should help deliver progressively better models, though much work remains to be done. One of the big challenges, for instance, is “to simulate the Earth’s clouds and how they might change with increasing carbon dioxide.”
In over three decades of research, he had published 130 highly regarded papers on atmospheric dynamics and climate change. As well as contributing substantially to the Fourth Assessment Report of the IPCC (Intergovernmental Panel on Climate Change), he has served on the World Meteorological Organization Expert Team on Hurricanes and Climate.
