James J. McCarthy, Harvard oceanographer who focused attention on climate change, dies 75

In addition to his field work, Dr. McCarthy had served as director of Harvard’s Museum of Comparative Zoology.
In addition to his field work, Dr. McCarthy had served as director of Harvard’s Museum of Comparative Zoology.Suzanne Kreiter/Globe staff /file 2008

Based partly on the observations of Harvard University oceanographer James J. McCarthy, the first paragraph of an August 2000 New York Times story was brief and blunt: “The North Pole is melting.”

He was a lecturer on a natural history tour of the Arctic that summer and was surprised by what he saw — and more importantly, what he didn’t see — when the ship reached the North Pole. The typical thick, multiyear ice was absent.

“What was really unusual was that over a period of two weeks we never had a day of what would be considered normal ice,” he told the Times. “When we reached the pole and found open water, that simply punctuated what we were seeing everywhere. These were conditions that did not seem representative of a transient phenomenon.”


An award-winning scientist whose observations about the pace and intensity of climate change inspired and informed students, colleagues, and politicians, Dr. McCarthy died Dec. 11 of pulmonary fibrosis. He was 75 and lived in Arlington.

“Dr. James McCarthy was an amazing man, a loyal friend, world-class oceanographer, a passionate advocate for science and for our climate balance,” former vice president Al Gore wrote for a Harvard University Center for the Environment tribute webpage.

“Nobody communicated the importance of the climate crisis in the context of the oceans as eloquently and passionately as Jim,” added Gore, who shared the Nobel Peace Prize in 2007 for his work focusing attention on climate change.

The Alexander Agassiz professor of biological oceanography and director emeritus of the Museum of Comparative Zoology, Dr. McCarthy was awarded the 2018 Tyler Prize for Environmental Achievement, whose presenters hailed him for having “fostered and led cooperative efforts among scientific disciplines to forge new, global-scale perspectives on environmental change.”


In 2008, he received the Walker Prize from the Museum of Science in Boston, which honors “meritorious published scientific investigation and discovery.”

Dr. McCarthy also had led a working group and was lead author on an assessment report for the Intergovernmental Panel on Climate Change, which shared the 2007 Nobel Peace Prize with Gore.

“Jim’s own research on biological oceanography probed the nitrogen cycle in the oceans, seeking to understand how the ecology of plankton affected and was affected by nutrient cycling,” Dan Schrag, director of the Harvard University Center for the Environment, wrote for the center’s tribute page.

“But Jim’s impact went far beyond his own research,” Schrag added. “Jim promoted the best in all of us through his numerous leadership positions inside and outside of Harvard and also through his extraordinary devotion to students.”

Dr. McCarthy formerly chaired the board of the Union of Concerned Scientists. On its website, the organization’s current president, Ken Kimmell, called him “a passionate advocate for the essential role science plays in our democracy.”

Though Dr. McCarthy witnessed the impact of climate change firsthand and was a leading voice insisting that the warnings of scientists be heeded, he remained hopeful — partly because of what he saw each day on Harvard’s campus.

“This is the generation that will make a difference. I know college students. I live with 400 of them,” he told the Globe in 2008.

“I’m inspired by them,” he added. “I’m very optimistic.”


Dr. McCarthy and his wife, Sue, were deans of Pforzheimer House at Harvard from 1996 to 2009.

“He always was a joyous person,” she said. “He always was an optimist.”

In the 2008 Globe interview, Dr. McCarthy said he believed humanity had “turned a corner. People are feeling the urgency, and our politicians are following the people.”

And speaking at the event Harvard Thinks Green in December 2011, Dr. McCarthy reminded the audience that even incremental steps are important.

“Small changes, that often have no impact on our lifestyles, add up to significant change,” he said.

James Joseph McCarthy was born on Jan. 25, 1944, and grew up in Sweet Home, Ore.

He was the second of four children whose parents were Dr. James McCarthy, a chiropractor, and Errilla Gearhart, an elementary schoolteacher.

In an interview last year with Steve Curwood for the Public Radio International program “Living on Earth,” Dr. McCarthy recalled “a very formative moment” in childhood when he and his father were exploring a pond at the edge of the community. They collected water in a test tube and examined it under a microscope.

“I knew there were fish in those ponds and I knew there were bugs, but I had no idea what was living there in the microscopic realm,” he told Curwood.

That experience helped form Dr. McCarthy’s aspiration to pursue science and to be “inclined toward something that would have me involved in field work, rather than totally lab-based.”


He graduated from Gonzaga University with a bachelor’s degree in biology and received a doctorate in biological oceanography from the Scripps Institution of Oceanography in California.

At Scripps he met Mary Suzanne Tilsworth, whom he married in 1969.

“Jim was many things, but I think one of the driving forces in his life is that he was enormously curious about the world that he lived in and the people. There was so much to learn and know,” she said.

“He also was an incredibly kind and compassionate person in the best possible way,” she added. “He let people be themselves, but he was always encouraging them.”

Away from work, Dr. McCarthy was drawn to the precise discipline of fly-fishing. He also made furniture and engaged in woodworking throughout his life.

He was a research scientist at Johns Hopkins University before joining the faculty at Harvard in 1974.

At Harvard, he helped found and had served as head tutor for the environmental science and public policy concentration.

“His commitment to students and to making the world a better place inspired me, and I am sure many others, to do more and to care more,” Missy Holbrook, a Harvard professor who is now the concentration’s head tutor, wrote for the university’s tribute page.

For “Living on Earth,” Dr. McCarthy said he believed the importance of climate change had become an integral part of the lives of those in the next generation.

“What more than anything else gives me hope is seeing the young people today, the college-age population who are learning about this subject,” he said, adding that “wherever they go, whether they go into business and into the public sector, any position in any career, they’re carrying with them an understanding.”


In addition to his wife, Sue, Dr. McCarthy leaves their two sons, Jamie of Houston and Ryan of Brooklyn, N.Y.; a brother, Richard of Cottage Grove, Ore.; and two granddaughters.

A memorial service will be held at 2:30 p.m. Saturday in Memorial Church in Harvard Yard.

Though optimistic, Dr. McCarthy stressed that addressing climate change is a task that can’t be ignored.

“If you lose a day working on this problem now, it’s not like you can work an extra day later and catch up,” he told Curwood.

“The carbon dioxide we’re putting in the atmosphere now, a portion of that will be in the atmosphere hundreds of thousands of years from now,” he added. “So everything you can do to slow it today makes tomorrow easier.”

Bryan Marquard can be reached at bryan.marquard@globe.com.