Low-energy astrophysics: How scientists are trying to save the Earth

Listen to the scientists. That's what we say. When lots of different scientists, working separately, are turning up evidence that the Earth is getting warmer and human activities are to blame, then we should heed their warnings.

Scientists, from many different disciplines, say that their research shows we should be concerned about climate change. If we want to reduce our risk, we'll have to start using less fossil fuels. That's a big shift in the way the world thinks about energy. It's bound to change our lives—and we may not necessarily like all the changes. And that fact begs a question: Do the scientists who sound the alarm on climate change have a responsibility to take the lead on energy change?

Phil Marshall thinks so. He's an astrophysicist. That may not be a field of science you immediately associate with the study of climate change, but there's actually a surprisingly strong connection. Astrophysicists know a lot about planetary atmospheres. From their work, we've learned more about the greenhouse effect—the way higher carbon dioxide concentrations in an atmosphere make a planet warmer. In 2004, the American Astronomical Society called for policy makers to base their decisions on the weight of scientific evidence. Climate change is real, they said, and politicians need to recognize that fact.

But astrophysicists also use a lot of energy. Like many scientists, they rely on energy-intensive technologies for gathering data. But, for astronomers, using that technology often means traveling halfway around the world on a jet plane, burning fuel all along the way. To meet all our energy needs, Americans use the equivalent of roughly 250 kilowatt-hours of electricity per day, per person. But if that American is an astrophysicist, they have to add another 133 kilowatt-hours per day to their tab.

That's why, in 2009, Marshall spearheaded the writing of a manifesto. Low Energy Astrophysics—a pun on "high energy astrophysics", which is the study of things like supernovae and black holes—was a white paper, co-authored by 30 astrophysicists. The goal: Get scientists to look at their own energy use, and then convince them to set an example for other people to follow.

"How can we ask people to fly less if we ourselves are doing lots of flying in the course of our work? How can we ask people to turn their thermostats down and put on sweaters if we are using whole towns' worth of electricity colliding particles together?", he says. "We have to explain the numbers to people, but then we have do everything we can to clean up our acts—just like we are asking them to."

It's important to clarify one thing: Astrophysicists use a lot of energy as individuals, but astrophysics is not a major contributor to America's overall energy use. Collectively, we as Americans use so much energy that this one profession—energy-intensive as it is—barely registers. Each year, Americans consume 98 quadrillion British Thermal Units of energy. That amount of energy is enough to boil away the Great Salt Lake into a dry plain—twice. Phil Marshall and his co-authors estimate that astronomy represents only about .001% of that energy use.*

This isn't about reining in a science that's set to doom us all. Instead, when Marshall and his cohorts ask other astrophysicists to use less energy, they're making the argument that scientists need to set an example. Significantly reducing the amount of energy Americans use is going to take some large-scale cultural change. And Marshall thinks scientists can lead that charge. In the Low-Energy Astrophysics manifesto, he and the other 29 signers asked scientists in their field to start by making research infrastructure more energy-efficient, cutting back on the number of airplane flights they take, and—most importantly—making sure people notice when they do those things.

That last bit really is a big deal. Obviously, if you're hoping to change the way Americans live, you probably ought to make sure they know what you're up to. But, even within the astrophysics community, communication matters. The Low-Energy Astrophysics manifesto didn't really point out any mind-blowing discoveries. In fact, astrophysicists all over the world were already quietly plugging away at reducing their own carbon footprints. Trouble was, few of them were aware of each other.

"What we found is that there's a lot of people that are doing a lot on their own, at home, in communities, but we're all working independently," says Bernadette Rodgers, Head of Gemini South Science Operations at the Gemini Observatory. In fact, until Low-Energy Astrophysics was published, Rodgers was one of those disconnected do-gooders.

In 2008, Rodgers was part of a group led by Peter McEvoy, Gemini facilities manager, which launched a campaign to make the Gemini Observatory—actually two facilities, one in Chile and the other in Hawaii—more energy efficient. Pooling ideas from Gemini staff, they started making changes, both to the buildings and equipment, and to the way people worked.

For instance, a lot of an observatory's energy use goes to air conditioning. There's a couple of reasons for that. First, like any facility that's home to a large collection of computers, observatories have to counteract all the heat that's thrown off by humming PCs, laptops, and servers. If you don't cool the building, that heat can damage the very machines that create it. But observatories also have special cooling problems. High up in the dome, every telescope has its own, personal cooling system.

"You want the mirror and support structures to be in thermal equilibrium with the outside air while you're observing," Rodgers says. "It improves the quality of the image. You know how, on a hot day when you look down a road, the image kind of shimmers? The quality of an image that you see, the sharpness, depends on disturbance in the air, and that relates to temperature variations."

To reduce the amount of energy it uses to keep things cool, Gemini bought more-energy-efficient air conditioners. But the facility managers also changed the way they cooled the telescopes. After reviewing the temperatures in the dome, they figured out that they were actually keeping the telescopes too cold. They found that adjusting the thermostat to the temperature at the start of the previous night, rather than the lowest temperature during the night, reduced the cooling but still kept the telescope cold enough to be ready for observations. Let the telescopes get a little warmer, and you save some energy. Despite adding a lot of new, energy-intensive equipment, the Gemini telescope in Hawaii uses about the same amount of energy it did in 2007. That's not quite as impressive as an overall reduction, but it still matters, given how much more energy the facility would have been using by now if it wasn't so efficient.

The base facilities, down the mountains from the two telescopes, are where the biggest impacts have happened. Since 2007, the Gemini facility in Chile has reduced its electricity use by 25%, while the one in Hawaii has cut electricity by 31%.

But the biggest astrophysics energy hog is air travel. That's especially true at Gemini, where scientists and support staff often travel back and forth between Chile and Hawaii several times a year. And it's true for individual astrophysicists, as well. Astrophysics is a small, and particularly international, community, with researchers from all over the world working together and sharing expensive pieces of equipment. Many of the astrophysicists I talked to told me that one of the things that had originally drawn them to that field of science was the opportunity for travel. Study the stars, see the world.

Now, many of them are making the emotionally difficult decision to spend more time on the ground.

At Gemini, for instance, they were able to reduce air travel by 23%, just by raising awareness and getting people to think about whether trips were really necessary.

Another way to do reduce air travel is through virtual astronomy. Traditionally, an astrophysicist had to fly halfway around the world and physically sit in the telescope herself, making observations and studying the stars. Today, that story is romantic, but not strictly necessary. Some observatories, including Gemini, operate in "queue mode"—astrophysicists put in research requests and observatory staff gather the actual information, deciding whose research gets done when based on a complicated algorithm that factors in both importance of the research, and weather conditions on a given night.

Another option is to use the telescope in remote mode. Here, an astrophysicist still gets assigned a night, or block of nights, when the telescope is dedicated solely to her. But, instead of traveling to the telescope, she links in and controls it via the Internet. Meanwhile, on-site observatory staff are available to help make adjustments or solve emergency breakdowns.

Both these systems have flaws. For instance, if your research isn't deemed important enough, you might wait forever and never get any data back from a queue-mode telescope. But there's no doubt that they cut down on hemisphere-hopping flights.

The energy changes made by people like Phil Marshall and the staff at the Gemini Observatory are good. But, until recently, they kind of happened inside a vacuum. The scientists weren't aware of each other, and few outsiders knew what was going on, either. That lack of awareness was so complete that, to a certain extent, it actually made all the effort somewhat irrelevant. On a personal level, or an organizational level, what the astrophysicists were doing did matter—they were reducing their own carbon footprints. But those personal changes didn't do much to alter the course of climate change.

For instance, in 2009, John Lacy, a professor at the University of Texas, dropped out of SOFIA—a project aimed at building an airborne telescope that would be flown around the skies on a 747. SOFIA could get astrophysicists a clearer view of space than they could capture on the ground, without some of the size constraints of a space-based telescope. Lacy had designed one of the instruments that was a part of the SOFIA telescope. But he eventually decided that he didn't want to be a part of a project that would—on its own—double the carbon footprint of the entire field of astrophysics. He dropped out, but SOFIA went on, unfazed.

"The instrument I was working on is still around. My getting out of SOFIA didn't really change much," Lacy says. " If I could convince astronomers to cancel SOFIA entirely, I would. I've wondered whether being more vocal would be more productive."

That, astrophysicists say, is the value of the Low-Energy Astrophysics manifesto. Since the paper was published, it's helped forge connections between the scientists who were, previously, working alone. Phil Marshall met Bernadette Rodgers and other environmentally-minded researchers. Rodgers discovered organizations like the Union of Concerned Scientists. And Rodgers, Marshall, Lacy and 3 other astronomers organized the first professional astronomy "green" meeting as part of the American Astronomical Society bi-annual meeting in January 2010. Since then another astrophysicist, James Lowenthal, Associate Professor of Astronomy at Smith College, has started a sustainability committee as part of the American Astronomical Society. It's this last development, still in its infancy, that the astronomers hope will help them turn personal decisions into public good.

Through the AAS committee, the astrophysicists I spoke with hope to make some big statements about energy efficiency and conservation. Their first goal: Convince the AAS, as a whole, to make it easier for its members to attend conferences virtually—or, better yet, encourage them to make whole meetings virtual-only.

Astrophysics, as a field, has a big public profile. (Admit it, this article was instantly more appealing because it involved people who study outer-space.) Lowenthal thinks his committee can combine astrophysics' energy-saving efforts with astrophysics' instant publicity appeal and end up with something that really inspires large numbers of Americans to use less fossil fuels.

But first this relatively small—and relatively young—group has to convince the rest of their peers to sign on. Neither Marshall, nor Rogers, nor Lacy, nor Lowenthal are sure how astrophysics, as a whole, will react to what they're trying to do. So far, nobody has been hostile to the goals of the AAS Sustainability Committee, but open hostility isn't the only potential roadblock. The AAS might simply ignore, or water down the Sustainability Committee's recommendations. That's especially a possibility when it comes to reducing air time. Lowenthal suspects that there would be pushback if the Committee actually suggested shutting down SOFIA, for instance. And he has doubts about whether other committees would be willing to have their meetings over Skype, the way the Sustainability Committee has done. But it's worth trying, he says. If they do this right, the actions the Sustainability Committee takes can influence other astrophysicists, whose actions can influence the general public.

"People's minds aren't made up by receiving information, but by the perception that everybody else is doing it. Individual changes matter by setting the norm and sending the message that this is part of the public discussion," Lowenthal says. "On my own, cutting a couple of flights will save as much as several tons of carbon dioxide, but there are few astronomers—only 6000 or 7000 in the US—and we're small potatoes. The multiplier effect comes from our having relatively high profile status."

For more information: Check out the Low-Energy Astrophysics wiki.