The Science is There. The Numbers Add Up. This Is Doable.

May 27, 2015

Tim Lucas, 919-613-8084,

Drew Shindell sees real opportunity for us to make progress on global warming, air pollution and food security if we work smarter.

Drew Shindell is a man on a mission. Since 2011, he’s been leading the charge to promote a new, more winnable approach to fighting the war against climate change. 

In a series of landmark studies and assessment reports, he’s shown that by aggressively curbing emissions of methane, black carbon and other potent short-lived climate pollutants (SLCPs) in addition to much longer-lived carbon dioxide, we could slow the rate of global warming by half over the next several decades and save 45 million lives.

“Short-lived climate pollutants are the low-hanging fruit of the climate world. They remain in the atmosphere for only a brief time but account for as much as 30 to 40 percent of the total short-term rise in global temperatures,” says Shindell, who joined the Nicholas School faculty as professor of climate sciences in 2014.

Expanding our mitigation strategies to target these short-lived drivers of global warming makes sense economically, politically and in terms of human health, he says.

Air pollution linked to SLCPs is the leading environmental cause of premature death. Reducing our exposure to these pollutants, particularly soot and other particles, would annually save up to seven million lives worldwide and improve respiratory and cardiovascular health for tens of millions of people. It would prevent 180,000 non-fatal heart attacks, 18 million missed work days and 11 million missed school days in the United States alone.

Curbing emissions that lead to tropospheric ozone, another potent SLCP, would boost agricultural economies and enhance food security for millions of people by increasing global crop yields by about 1 billion metric tons a year.

These gains could send skeptics and vacillating world leaders a message that meaningful progress is possible, and perhaps set an example that helps us tackle more persistent carbon dioxide. 

Many of the technologies and tools needed to reduce SLCP emissions already exist or could be developed and scaled up for widespread use at a fairly modest cost, Shindell stresses.

Emissions of black carbon, or soot, can be reduced through measures as simple as installing filters on diesel engines, replacing inefficient cookstoves, and banning the open burning of agricultural waste. Methane can be reduced through retrofits or upgrades to existing emissions-control technologies where most leaks occur: oil and gas wells, leaky pipelines, municipal landfills and wastewater treatment plants. Many of these actions pay for themselves, as the captured methane can be used for energy.

Quantifying and communicating the benefits of this integrated approach to climate change and air pollution has become a core focus of Shindell’s scholarly output.

In addition to his ongoing research, he chairs the scientific advisory panel to the international Climate and Clean Air Coalition, chaired the 2011 Integrated Assessment of Black Carbon and Tropospheric Ozone by the UN Environment Programme (UNEP) and World Meteorological Organization, and was a coordinating lead author of the key chapter on anthropogenic and natural radiative forcing in the 2013 Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).

He’s also testified on climate change and air quality before both houses of Congress, the World Bank and the United Nations Framework Convention on Climate Change.

“The point I’m trying to drive home is that by working smarter we have a real opportunity to make progress on three critical issues: global warming, air pollution and food security,” he says. “The science is there. The numbers add up. This is doable.”


Although it’s too early to gauge its full impact in science and policy circles, Shindell’s call to action appears to have struck a chord.

As a result of his leadership, the 2013 IPCC report shifted focus from measuring the causes of climate change in terms of concentrations of greenhouse gases in the atmosphere to including emissions of all climate pollutants.


Testimony photos by Rick Reinhard.

Membership in the Climate and Clean Air Coalition–which was founded in 2012 in direct response to the UNEP report Shindell chaired and a related paper he published in Science–has grown from its initial roster of six nations to a current roster of 44 nations and 54 nongovernmental organizations, including big guns like the World Bank and World Health Organization.

“This has been the most direct link from science project to policy initiative that I’ve ever been part of,” he says. “I’m honestly floored.”

He shouldn’t be.

With more than 170 peer-reviewed papers and dozens of high-profile assessment reports, invited testimonies, book chapters and keynote presentations to his credit over the last two decades, Shindell is arguably one of the most influential voices in climate science and atmospheric chemistry today.

His discipline-blending work has reshaped scientists’ understanding of the natural and human drivers of climate change and air quality and how they interact.

NASA, the National Science Foundation, the American Geophysical Union, the American Association for the Advancement of Science and other leading agencies and organizations have all bestowed high honors on him for his contributions to climate research and outreach.

All things considered, it’s not a halfbad list of honors and accomplishments for someone who once looked down his nose at environmental science, and applied science in general.

“I only got into environmental research by coincidence,” Shindell admits with a laugh.

Growing up in 1970s in the East Bay region of California, a short drive from San Francisco and Berkeley, he was aware of the growing interest in the environment occurring all around him but didn’t see a future in it, at least not for him.

“I preferred the intellectual challenge of physics,” he says. 

The connection between physics and the environment, and basic and applied sciences, didn’t crystalize for him until he was an undergrad at the University of California-Berkeley and took part in a research project studying a deadly gas eruption in Lake Nyos, one of two so-called “killer lakes” located in the central African nation of Cameroon.

In 1986, a large gas cloud erupted unexpectedly from volcanic Nyos, giving off large amounts of carbon dioxide that suffocated more than 1,700 people in surrounding villages. Shindell and the other members of the Berkeley team were tasked with explaining why the eruption had occurred with no advance warning, and what could be done to improve scientists’ ability to predict similar eruptions in the future.

“Applying physics to the study of such an event intrigued me,” he says. “It showed that environmental applications were relevant and interesting.”

After finishing his bachelor of arts in physics at Berkeley in 1988, he began doctoral studies in physics at the State University of New York at Stony Brook and spent the summer of 1989 conducting research on fundamental physics at the nearby Brookhaven National Lab synchrotron.

It was a life-changing experience. Just not in the way he anticipated.

“It was fascinating from an intellectual perspective, but by summer’s end I realized I didn’t want to spend the next few decades of my life doing something so esoteric,” he says. “I started looking for something more applied.”

A group of other physicists at Stony Brook had recently begun exploring the complex chemistry responsible for the ozone hole over Antarctica. Reviewing their work, Shindell realized he could help shed light on what was going on by building a model that would help the scientists better understand the measurements they were taking of ozone-depleting chemicals in the atmosphere. He joined the team.

“Here was a chance to apply my work in way that had clear benefits to society and involved travel,” he says. “I was in!”

His newfound focus took him to Antarctica three times and northern Greenland twice and became the basis for his doctoral thesis, for which he developed a photochemical model that calculated changes in atmosphere chemistry by comparing measurements of ozone depleters and ozone itself.

After graduating in 1995, he was hired by the NASA Goddard Institute for Space Studies at Columbia University to integrate his atmospheric photochemistry model into a climate model recently developed by NASA scientists.

“Back then, most climate models had no atmospheric chemistry whatsoever,” he explains. “Scientists knew ozone and other shorter-lived chemicals in the atmosphere affected climate, but the two areas of study had always been viewed as separate. We were just starting to realize we needed a more integrated understanding.”

For Shindell, it was a case of being in the right place at the right time, with the right skill set.


Major papers soon followed, including two seminal works published one month apart in 1999.

The first study, published in March in Nature, revealed that the greenhouse effect from burning fossil fuels was affecting weather and stratospheric wind patterns over the northern hemisphere more than previously thought, partially as a result of chemical processes. This was causing dramatic regional shifts in median temperatures. Some Arctic regions such as Greenland were warming during winter at a rate nearly 10 times that of the global average.

The second study, published in April in Science, showed that the interaction of increased solar activity and anthropogenic chemicals in the upper atmosphere also affected wind patterns and caused regional climate shifts.

Taken together, the two studies yielded strong new proof that increased emissions of manmade pollutants in Earth’s atmosphere were inextricably linked to climate change, especially on regional scales.

What the studies didn’t prove was equally important, Shindell stresses. Neither study found evidence to support skeptics’ claims that increased solar activity or natural variability was the primary driver of global temperature increases.

“Our model clearly confirmed that greenhouse gases were playing the dominant role,” he says.

A third paper, published in Science two years later, built on this foundation and, in the process, took aim at one of the denier camp’s most oft cited objections to mainstream climate change theory: the Little Ice Age of the 17th century.

“During the Maunder Minimum, or the so-called Little Ice Age, there were almost no sunspots, and it got really cold in the eastern United States and Europe. This was the only time in recorded history that New York harbor froze over completely,” Shindell explains.

In 1998, however, when climatologist Michael Mann and two colleagues published their now-famous large-scale reconstruction of Earth’s climate dating back to the year 1400, their model showed only slight changes in climate during the 17th century.

The only major global temperature flux reflected in the model was rapid warming in the modern era, represented by a short, sharp upward spike at the end of a long, relatively flat line of temperature averages, giving the model a shape that vaguely resembled a hockey stick.

The following year, Mann and his team published a revised large-scale reconstruction dating back to 1000. Once again, it showed only slight changes during the 17th century. To compound matters, the new model also showed only a modest change during a time prior to 1250 known as the Medieval Warm Period.

Critics pounced. The flaws in Mann’s reconstruction were proof that climate data were unreliable, they claimed. And the so-called “hockey stick controversy” was born.

With the credibility of climate data at stake, Shindell decided to weigh in. With Mann as one of his co-authors, he ran his own model, which included the impact of atmospheric chemistry. It confirmed that the reduced solar output of the 17the century, combined with chemical feedback in the atmosphere— ozone—caused major regional climate changes but not a big overall change in global patterns.

Europe and parts of North America got colder, but other areas, including Africa and Australia, showed no major cooldown.

“This is why Mann’s large-scale reconstructions showed only slight global changes,” Shindell says. “It was a major finding, not only to validate Mann’s work and the agreement between climate data and models in general, but also to show that atmospheric chemistry played a much larger role than previously thought in affecting climate change, and that regional changes could be large even if global change was slight.”

The success of the paper, which has since been cited in nearly 570 other peer-reviewed studies, spurred Shindell to turn his sights to an even bigger challenge.

“The question I wanted to answer next was: Why do some regions change in one way, while others don’t? That was not well understood at all, but it was clearly crucial,” he says.


To unearth the answer, Shindell began to study tropospheric chemistry and the interactions of all SLCPs, not just ozone.

The more he discovered about the uneven distribution of SLCPs in the troposphere, their uneven contributions to anthropogenic forcing, and how they interact with longer-lived greenhouse gases like carbon dioxide, the more certain he grew that it was neither logical nor efficient to segregate climate change and air pollution as separate problems.

“Through my work with UNEP, the U.S. Climate Change Science Program and other initiatives, I was coming into contact with medical and agricultural researchers and economists who were studying the broader health impacts of air pollutants,” he says. “It became clear that we were not dealing with global warming or air pollution, it was global warming and air pollution. They were directly related and we had to attack them as one.”

Working with these experts from other fields, Shindell expanded the focus of the assessment report he was chairing for UNEP. “We quantified health impacts, we quantified crop yield impacts and we quantified climate impacts. It was like preparing a menu ready-made for policymakers,” he says.

“We showed that we had 16 measures through which we could demonstrate that there were multiple benefits of reducing short-lived climate pollutants.”

UNEP published the assessment report in 2011 and founded the Coalition for Climate and Clear Air the following year to achieve the objectives Shindell and his colleagues had set forth. By 2013, the IPCC had shifted its focus as well.

Shindell’s mission to promote an integrated approach to climate change and air quality had reached critical mass.

But he’s not slowing down anytime soon.

Since joining the Nicholas School faculty last summer, he’s presented a policy talk about the benefits of SLCP reductions to delegates at COP15 in Lima, Peru, at the invitation of the U.S. State Department. He’s testified before Congress to support passage of the Super Pollutants Act of 2014, which would provide financing to help underwrite costs associated with emissions reductions. And he’s written another major research study.

The newest study, published in Climatic Change in February, calculated the true costs of our energy choices once the full environmental and health damages associated with their emissions are figured in.

Among other eye-opening findings, the study showed that a gallon of gasoline should cost around $3.80 more a gallon than we currently pay, the cost of heating our homes with natural gas should more than double; and the cost of our monthly bills for coal-fired electricity should more than quadruple. Solar and wind power, by contrast, are cheap.

“This builds on everything I’ve ever worked on: climate change and air quality, agriculture and human health, SLCPs and carbon dioxide. And it brings it down to a ground-floor policy-relevant level,” he says.

When he’s not working, Shindell, 48, likes to unwind by playing strategy games with his wife Miriam, a psychologist, and their three children: Cary, 15; Oliver, 12; and Leah, 6.

He also enjoys a good run. “Preferably something from a 5K up to maybe a halfmarathon,” he says. “At those distances, it’s not all about speed or endurance. It’s a balancing act. You have to pace yourself and know when to kick it in.”

Tim Lucas is senior writer for Dukenvironment magazine and is the Nicholas School’s director of marketing communications.