Wallace Broecker, prophet of climate change

Wallace Broecker, prophet of climate change

A global explorer of the oceans and the atmosphere. 1931-2019

Wallace Broecker, a geochemist who initiated key research on the Earth's climate history and human influence on it, died on February 18 in New York. He was 87 years old. The cause was congestive heart failure, said his family. His death was confirmed by Columbia University's Lamont-Doherty Earth Observatory, where he had a career spanning nearly 67 years.

One of the first scientists to predict an impending rise in Earth's temperature due to human production of carbon dioxide, Broecker was credited with introducing the phrase "global warming" into the scientific lexicon in the 1970s. Much of his work was about the oceans. His studies of marine chemistry included a map of global ocean circulation and its powerful effects on the climate. His studies have also helped lay the groundwork for many scientific works in various fields. Not content to do research, he befriends and extends his influence to influential figures in government and business.

Wallace Broecker, circa 2010 (Bruce Gilbert, courtesy Lamont-Doherty Earth Observatory)

Broecker – universally known as Wally – first made an unlikely scientist. Born November 29, 1931, second of five children, he grew up in Oak Park, a suburb of Chicago, Illinois. His father, also named Wallace, ran a gas station. His mother was the old Edith Smith. Both parents were evangelical Christians who rejected modern geological theory for the literal biblical interpretation that the Earth was a few thousand years old. They also banned drinking, dancing and watching movies. Broecker attended Christian Wheaton College, a fundamentalist in Illinois, and then the recent alma mater of preacher Billy Graham. While still a student, he married the old Grace Carder and talked about becoming an insurance actuary.

Broecker was dismissed after a former Wheaton student helped him organize a laboratory internship in the summer of 1952 in what was then called the Lamont Geological Observatory, in Palisades, NY The student was Paul Gast , who then directed NASA's Moon-Rock program. At Lamont, Broecker worked with J. Laurence Kulp, a pioneering geochemist in the field of radiocarbon dating, a revolutionary new method that allowed researchers to determine the age of materials 40 years ago. 000 years.

On his own, Broecker was having fun tinkering with the lab equipment, and he was excited about the grand new chance to make discoveries about nature using carbon dating. He was posted to Colombia this fall and continued to work with Kulp. This decision suggested that he had rejected at least some of his family's religious beliefs; However, other students laughed at his past and called him a "theo-chemist". While other students were sent on ocean research cruises, he stayed off the list for the first eight years. Nevertheless, he got a PhD. in geology in 1958 and stayed around, gradually rising to the forefront of prominence. In a memoir of 2016, he called Lamont "my garden of Eden".

"My greatest joy in life is discovering something," he told The New York Times in 1998. "I find something about every six months or so, I write to this topic and I encourage research, and that's the joy of my life. "

One of Broecker's first accomplishments was a series of articles describing the idea that tens of thousands of years were needed for water to circulate between the shallow and deepest regions of the world's oceans. His analyzes of the carbon isotopes collected by Lamont ships around the world have shown that water can make the transition in just a few centuries – a discovery has shown that the oceans are much more dynamic than expected. This in turn implied that the oceans could potentially affect the composition of the atmosphere, or vice versa.

With the help of chemical tracers and other data, Broecker painted a picture of the global ocean circulation and its consequences for the climate. (Courtesy Lamont-Doherty Earth Observatory)

From 1960, Broecker sailed on many oceans and seas of the world. In addition to sampling the water, he maintained the instruments, helped the winching seduce the sediment cores of the seabed and threw the dynamite overboard to produce explosions whose echoes were read to represent the bottom. In the 1970s, he co-directed a US-funded global program to use a wide variety of trace metals, nutrients and isotopes of radioactive elements to map the circulation. from the deep ocean, gas exchanges with the atmosphere and other sources. marine processes. This collective work provided the foundation for virtually all subsequent studies on marine chemistry and the relationship of oceans to climate. It's Broecker who commented on a documentary film about the project during a cruise from Tahiti to San Diego. He used related geochemical methods to study lake waters, sediments, and rocks in Canada and the western US, looking for clues about past climates, with a particular interest to them. ice ages.

From the beginning, Broecker is interested in how the oceans absorb carbon dioxide from the air and its effects on the climate. The history and behavior of atmospheric carbon dioxide were poorly known in its infancy, but by the early 1970s, other researchers had analyzed the ice cores of Greenland ice and had shown that they had not been able to control the environment. they could track atmospheric CO2 levels during a long time ago. Work by others has suggested that higher CO2 levels could be correlated with periods of warming. And scientists had speculated since the 19thth century, the increase in the production of CO2 of human origin could potentially warm the planet; Some of Broecker's contemporaries, including Charles Keeling of the Scripps Institution of Oceanography, were already tracking CO2 levels in real time and considering the effects.

In August 1975, Broecker synthesized his research and that of other researchers in the newspaper Science in an article entitled "Climate change: are we on the brink of pronounced global warming?" It was later said that it was the first time this phrase was used in a scientific article. He explained that humans change the climate by emitting CO2; it was not yet obvious, because the world was living what it believed was a 40-year natural cooling cycle that masked the effects. He predicted that the cycle would reverse soon and that man-made warming would become dramatically visible. It eventually turned out that he had misinterpreted some of the data relating to ice cores, but that he had a good picture overall. Since 1976, temperatures have started to rise and since then have been on Broecker's path.

Bill Clinton, President, receives the National Medal for Science, 1996 (courtesy Lamont-Doherty Earth Observatory)

The world of science has quickly adopted "global warming," including in the first large-scale report on the subject, published in 1979 by the National Academy of Sciences of the United States. Decades later, when a few credited Broecker with inventing this sentence, he slapped it as a "stupid luck". He warned that he would turn around in his grave if someone put a "global warming" on his tombstone. Once, he offered $ 200 to any student who could find a quote earlier for this sentence. (A postdoctoral medical student found it in an editorial in the Indiana Hammond Times in 1958. He was apparently not retained at that time.)

Broecker and a handful of other scientists began briefing government leaders on climate change in the 1980s. He testified at the first congressional hearings on the subject, conducted in 1984 by Tennessee representative Al Gore . Over the years, as science progressed, Gore and other politicians met and consulted Broecker many times to get it explained.

In the mid-1980s, Broecker synthesized a large picture of the global ocean circulation from his studies and those of other authors. He nicknamed it the "conveyor of the great ocean". In simple terms, it is a vast river of shallow warm waters from the South Pacific to the Indian Ocean, circling Africa and then heading north across the Atlantic. Once it reaches Arctic cold water, this water cools and flows near northern Europe. From there, it crosses the chasm to warm up, get up and start the cycle again. According to Broecker, the flow is so important that it must contribute to the regulation of the global climate by circulating large amounts of heat from one place to another. This idea quickly became a general consensus.

Diploma of College Studies (courtesy Columbia University)

Broecker then came up with the idea that the conveyor could suddenly switch on and off, causing profound climate change – not millennia, as many thought, but perhaps over decades. He referred to an apparently rapid cooling around 12,000 years ago, which plunged Europe and other regions into a temporary freeze. Paradoxically, he explained, the cause could be global warming and the collapse of the northern ice sheets, which resulted in a fresh water impulse that pushed the conveyor back. He warned that "the uncontrolled experience" of modern man-made warming could lead to similar rapid changes. He liked to say, "The climate system is an angry beast, and we prick it with sticks."

Climatologists are still debating whether and how rapid climate change could occur today. Despite this, Broecker's ideas were taken up and exaggerated in the 2004 film Two days later, which caused a tsunami caused by climate change, engulfing Manhattan, then turning into a layer of ice – the same day. This is perhaps the only pop song on physical oceanography, "Uncle Wally's Tale", singer Tom Chapin, which explains their credibility. (Chapin was Broecker's brother-in-law, married to Broecker's younger sister, Bonnie.)

In the 1990s, Broecker was chief scientific advisor for Biosphere 2, an experimental desert environment in Arizona, designed to mimic the workings of land, oceans, and air on a small scale. Columbia had just taken over the scientific management, and the private sector was temporarily entrusted to a consultant named Steve Bannon, future adviser to US President Donald Trump, and a great enemy of the US efforts to fight against change climate. "An intense guy. In fact, I liked him, "said Broecker at New republic in 2017. After the 2016 elections, Broecker was alarmed by the fact that Bannon may have forgotten science or not, and tried to contact him to restore it. He has never heard of return.

Broecker (center) aboard the Melville Research Vessel, in the Pacific Ocean, in 1973 or 1974. The barrel was used to bring seawater for analysis purposes. carbon isotopes. (Courtesy Lamont-Doherty Earth Observatory)

Broecker is the author or co-author of nearly 500 research articles and at least 17 books. Many of the books were self-published spiral-related issues, distributed free of charge to anyone interested. Most commercial included the 2008 Fixing climate (with science journalist Rob Kunzig), an autobiographical look at the evolution of modern climate science. He also collaborated with Harvard oceanographer Charles Langmuir on How to build a habitable planet, widely used text on the origin and evolution of the Earth, published for the first time in 1984 and developed in a 2012 edition. Broecker has mentored about 50 graduate students from Lamont, many of whom have pursued an eminent career.

There is no Nobel Prize in Earth Science, but Broecker has received honors and millions of dollars in awards from foundations, governments and scientific societies. He has received honorary degrees from Harvard, Cambridge and other universities. He was elected to the Royal Society of London and the National Academy of Sciences of the United States. In 1996, he received the National Science Medal from US President Bill Clinton. He has reinvested most of the cash rewards in research.

In the summer of 2001, billionaire Gary Comer, founder of the clothing company Lands' End, managed to get his big yacht into the Northwest Passage of Canada. Long impracticable because of the ice, it was suddenly opened because of global warming. Comer was intrigued by his own feat and looked for Broecker to find out more. Both became fast friends. Broecker, who then enters his 70s, credits the businessman with having "adopted" him and revived his career when he was considering retiring. Using a yacht and a private plane from Comer, they have made many expeditions together in the Far North. Under the influence of Broecker, Comer donated some $ 25 million to fund climate scientists around the world and to build a new large geochemical building in Lamont.

Broecker, who suffered from dyslexia, never learned to type or use a personal computer. He wrote with a pencil and a notebook and asked his associates to retype manuscripts and e-mails. He was known for his friendly behavior, but also for his brutality and his volcanic temperament; he has publicly pinned graduate students and top scientists for their botched work. "He alone has pushed more understanding than probably anyone in our field," said Richard Alley, a leading climatologist at Pennsylvania State University. "He is intellectually so huge in the functioning of the Earth system and in its history, that we all follow Wally in one way or another."

In recent years, Broecker has increasingly spoken of the dangers of climate change, but has confessed that many remain unknown. "It's disconcerting to study the Earth system because you realize that nature is really complicated," he told CBC television. He pleaded for a possible abandonment of fossil fuels, but saw little hope that it would happen soon. "I do not think we can target the poor of the planet to stay poor, just to avoid the accumulation of CO2 in the atmosphere," he said. "The charcoal is going to be burned and we can not do anything about it. [H]How are you going to prevent people from using it? As a workaround, he advocated emerging technologies to suck CO2 into the air and store it in the soil.

Grace Carder, Broecker's first wife, passed away in 2007; they had been married for 55 years. They had six children, five of whom survive him: Sandra Broecker of Dumont, N.J .; Cynthia Kennedy of Harrington Park, N.J .; Kathleen Wilson of Oxford, Miss .; Scott Broecker of Pacific Grove, California; and Cheryl Keyes of Morristown, New Jersey. A daughter, Suzanne Broecker, died earlier. In 2009, he married Elizabeth Clark, who had worked in his lab for many years and continued to work with him. she survives him. He is survived by his sisters Judith Redekop of Tucson, Arizona, and Bonnie Chapin of Piermont, New York, as well as seven grandchildren and seven great-grandchildren.

Broecker's last extended job was CO2: climatic engine of the Earth, hovering over the subject since the deepest hour, published in the fall of 2018. After that, his health began to deteriorate, but his colleagues claimed he had continued to discuss the latest research and ideas of new projects with death. During one of his last meetings with friends, he announced his intention to be cremated and asked another Lamont scientist, geochemist Sidney Hemming, to take his ashes at his next search campaign. Disperse them in the ocean, he tells him.

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