Press Release on Sustainability Session

The opening day of the 229th AAS meeting featured a special panel session, entitled "Geoengineering the Atmosphere to Fight Climate Change: Should Astronomers Worry About It?". The discussion featured presentations by four panelists, as well as questions both from committee members and the audience.

Geoengineering is a large family of potentially useful tools against climate change that might enable humankind to lessen the effects of global warming by intentionally changing the Earth’s climate, either locally or globally. Panelist Thomas Ackerman of the University of Washington gave an overview of possible ways to accomplish this. One way to do it that is often discussed in the popular press is to reduce CO2 via carbon sequestration. This is difficult, however, requiring (for example) immense amounts of additional forests, comparable in area to the continental US. Another possibility is to reduce incoming sunlight, for example, by inserting aerosol particles into the atmosphere.

Many of the climate change models considered by the International Panel on Climate Change require not only bending the arc on greenhouse gas emissions, but also reducing both emissions and the overall atmospheric level of CO2 through carbon sequestration to stabilize the climate and reverse global warming. Panelist Jane Long of the Breakthrough Institute pointed out that emsissions of CO2 remain in the atmosphere and affect climate for many hundreds of years, so climate change will continue to get worse until emissions are essentially stopped.  For this reason, solar climate engineering may also be important, as it could mitigate the rise in global temperatures and slow adverse effects such as glacial melt and coastal inundation. 

Astronomers are concerned about geoengineering, as well as climate change, for a number of reasons.  Observatories depend on the climate of their sites, requiring dry, calm and clear weather conditions. Increasing atmospheric aerosols would worsen the cloud cover and transparency at observatories, for example, and if the overall humidity were increased there could also be more storms.  However, climate change itself can produce worse effects, changing the climate drastically on a global scale.

David Grinspoon, a panelist and senior scientist at the Planetary Science Institute, pointed out that astronomers should be interested in geoengineering for a number of reasons. First of all, understanding what mechanisms can affect Earth’s climate will help us to understand the drivers of climate on other planets. In addition, we are now at the dawn of a new geologic era: the Anthropocene — an era marked for the first time by intelligent modification of our entire biosphere. This new era, which is the focus of Grinspoon’s recent book Earth in Human Hands: Shaping Our Planet’s Future, may be dangerous. These modifications might stabilize Earth’s system, but they might destabilize it instead.

Importantly, as Ackerman said, if we want to try to change the climate we have to choose the climate we want — we cannot maintain both global temperature and precipitation. This was echoed by Long, who emphasized that “there is no natural state [for Earth] — it’s all dynamic.” An equally interesting question, stressed by both Ackerman and Melville Ulmer, a professor of physics and astronomy at Northwestern University, is who gets to decide which climate might be chosen — in other words, what global temperature, what level of increase in cloud cover, and the like.

The discussion included not only a focus on geoengineering itself but also how we need to interact with decision-makers about the subject. Long emphasized that it’s important to understand transparency — not just to publish data, but also to engage policy-makers. At the same time, while there may be a need for geoengineering, now is probably not yet the time, since we don’t yet know enough about its effects, stressed Ulmer. This was echoed by Long, who agreed that, on the short term, it’s folly to attempt long-scale radiation-modification efforts because we are ignorant of the long-term consequences. Ackerman, however, opined, “I think there aren’t as many unintended consequences as you might think.”

A constant theme that ran through the session was that while there may be significant adverse effects on astronomy from geoengineering, astronomers have to realize that the global climate is more important. Besides, as Grinspoon mentioned, geoengineering Earth’s climate is not fundamentally different from terraforming Mars, Venus, or other worlds. So, by learning how to potentially mitigate the effects of climate change on Earth we are learning about climatology on other worlds as well as how to modify other planets for human habitability.

The Panelists

Our discussion featured an expert panel, including Thomas Ackerman, director of the Joint Institute for the Study of the Atmosphere and Ocean and professor of atmospheric Sciences at the University of Washington. He has written extensively on the subject, including research papers on marine cloud brightening and the ethics of geoengineering.  Dr. Ackerman's bio can be found at 

David Grinspoon, a senior scientist at the Planetary Science Institute and author of Earth in Human Hands: Shaping Our Planet’s Future. Dr. Grinspoon was the inaugural holder of the Baruch S. Blumberg NASA/Library of Congress Chair in Astrobiology, and is an advisor to NASA on space exploration. His specialty is astrobiology and the runaway greenhouse effect seen on Venus. His public writing has appeared in many publications such as Scientific American, Slate, Astronomy, and the Boston Globe, and he has won a variety of awards for that writing. His bio can be found at and his personal website is

Jane Long, a policy specialist at the Breakthrough Institute, was Chair of the California Council on Science and Technology’s California’s Energy Future committee and the Bipartisan Policy Center’s Task Force on Geoengineering. Dr. Long previously was Associate Director for Energy and Environment from Lawrence Livermore National Laboratory, the Dean of the Mackay School of Mines, University of Nevada, Reno, and Department Chair for the Energy Resources Technology and the Environmental Research Departments at Lawrence Berkeley National Lab. Her current work involves strategies for dealing with climate change including reinvention of the energy system, geoengineering, and adaptation. Her bio can be found at

Melville Ulmer, a professor in Northwestern University’s Department of Physics and Astronomy. Dr. Ulmer is an X-ray astronomer who has worked on designing new technologies for large space telescopes as well as various topics in cosmology. He is currently heading up an effort to design a 16-meter, space-based telescope, funded by NASA's Innovative Advance Concepts program.  Dr. Ulmer proposed the panel discussion two years ago by sending a letter to the then-president of the AAS, C. Megan Urry asking whether the AAS should take a position on geoengineering issues. His bio can be found at

The event was video recorded and webcast, and is available at For more information, please contact the AAS Sustainability committee (, chair James Lowenthal (, or Eric Perlman (, or tweet us @AAS_SC.

Grapevine 2017

posted Jan 8, 2017, 1:27 PM by Andria Schwortz

AAS Sustainability Committee Splinter Session
Geoengineering the Atmosphere to Fight Climate Change: Should Astronomers Worry About It?
Wednesday, January 4, 2017, 10:00 - 11:30 am
Texas 5 Room

Session Description

Geo-engineering is a set of proposed solutions to global climate change that involve intentionally modifying the Earth’s atmosphere and/or surface. Examples: injecting aerosols, water droplets, or other reflectors into or above the atmosphere to reduce incoming sunlight.

Will it work? What if it doesn’t? How much will it cost? What are possible side effects? Is it ethical?


10:00 Introduction

10:10 Panel discussion featuring:
Tom Ackerman (University of Washington)
David Grinspoon (NASA/GSFC)
Jane Long (Permeter Institute)
Mel Ulmer (Northwestern University)

11:00 Discussion and questions

A video of the session is available here.

Geoengineering Panel Video

posted Jan 4, 2017, 8:09 AM by Andria Schwortz   [ updated Jan 4, 2017, 9:39 AM ]

The video recording of the AAS229 geoengineering panel (Weds Jan 4, 10:00-11:30am) is available on FB c/o Geoff Clayton.

Geoengineering Debate at AAS229

posted Jan 3, 2017, 10:40 AM by Andria Schwortz

Tomorrow morning, Weds Jan 4, 10:00-11:30am, the AAS Sustainability Committee is hosting a panel discussion about geoengineering, climate change, and astronomy at the AAS229.  This will be located in Texas 5.  Spread the word!  

aas229 geoengineering discussion flyer

Video conferencing tips

posted Nov 9, 2015, 8:33 AM by Bryan Miller

We've added some tips for video conferencing, a good option for sustainable communications, to the recently renamed Resources, formally Teaching, page.

Gemini Observatory Green Energy Initiatives: A Key to Leaner Operations

posted Sep 11, 2015, 5:36 AM by Bryan Miller

Over the last five years the Gemini Observatory has been adapting itself to a 25% reduced operations budget due to the withdrawal of the United Kingdom from the Gemini partnership in 2012.  One goal of this effort is to save $1.5 million per year in non-labor operations costs.  A substantial fraction of that saving comes a reduction in energy use due to improved efficiency and new green energy initiatives.

The first step was to make the current facilities more efficient to reduce electricity use. We have already improved energy management at the La Serena base facility and remodeled both summit and base data centers to reduce the energy, and money, needed to cool computer systems.  Changes in progress or that are being planned include replacing aging chillers on the summits with more efficient models, updating the transformers in Hawai'i, and converting lighting to use LED bulbs.  Combined these efforts will save approximately $230,000 per year by 2017, assuming 2015 energy prices. Gemini will also continue to look for opportunities for additional savings.

In addition to efficiency savings, Gemini is investing in new green energy generation capabilities in order to reduce the amount of power that has to be purchased.  Most of this is happening on Hawai'i, where the electricity costs are much higher than the US average. The installation of 300 photovoltaic (PV) panels on the roof of the Gemini North support building on Maunakea has just been completed.  This 100kW system will save $60,000 at year.  Another 100kW PV system is also being planned for the roof of the Hilo base facility.  It is hoped that the installation contract will be approved by the end of 2015. Once fully installed this should save about $40,000 a year. Finally, a 200kW PV system is being planned for Gemini South on Cerro Pachón, Chile.  This should lead to an additional reduction in energy costs of  around $40,000 per year.  With these significant saving the investment in the panels should be returned within five years.

These efforts show how green energy makes financial sense as well as being good for the planet.  Between energy efficiency improvements and green energy production, Gemini plans to save approximately $370,000 per year (assuming 2015 energy costs), or about 25% of the desired non-labor savings.  In the process, Gemini's carbon footprint will be reduced by approximately 3500 tons of CO2 per year.

Climate education 101; climate scientist Don Chambers to speak at AAS

posted Jul 7, 2015, 6:15 PM by James Lowenthal

By Katy Garmany

We were all delighted with the engaged audience of about 60 people who joined us in January at the AAS meeting in Seattle. The first half of the session involved a fun, role playing exercise on how to talk to a climate change denier, but I will focus on the second half in which we addressed the issue in teaching climate change at the astro 101 level.

I  invited several  people who  are very involved in teaching climate change for an informal roundtable discussion: Ed Prather, Chair, AAS Education Committee; Travis Rector, member of AS Education Committee; Megan Donahue, co-author of an elementary astronomy textbook that several people have identified as very effectively including climate change;  and Greg Rudnick, who teaches a  section on climate change in his introductory astronomy class and is involved in KU sustainability teaching efforts.  (This panel was not  meant to be exclusionary; these are just people I was aware are doing this work!)

In the discussion, the  question was raised of how to make progress when the obstruction to understanding is psychological, not rational -- it's not a question of missing ideas and information.  Among the ideas that came up was that of inviting Katherine Hayhoe to speak at a future AAS meeting: she is a climate scientist and evangelical Christian, who communicates to Christian audiences about climate change from the perspective of an Evangelic. Hayhoe is featured in the documentary  "Years of Living Dangerously", a 9-part series.  Showtime is allowing the first episode on youtube as an advertisement for the whole series, which premiered in April, 2014.
The first episode directly addresses the political divide of opinion on climate change

Megan commented that students appreciate hearing the counter-arguments to the most common objections by climate change deniers. 

We urged the audience  to send us  links to useful teaching material  for the website. To this end I have begun posting some that I know about as well as some provided by various folks.  We will offer these on the teaching page of this website.  We have a sense that hands-on classroom activities are something that is most  needed.  A few that I especially like include:

-  "The Modern Atmospheric CO2 Record : Students compare carbon dioxide (CO2) data from Mauna Loa Observatory , Barrow (Alaska) , and the South Pole over the past 40 years to help them better understand what controls atmospheric CO2. This activity makes extensive use of Excel.

- University of  Colorado (Phet) interactive simulations.  There are a lot of different physics related units here, but note the one on greenhouse gases,

And we are excited to be planning  a special session for next January's AAS meeting in Florida.  Dr. Don Chambers, who is a climate scientist at U. Southern Florida and a lead author of the latest IPCC climate assessment, has accepted our  invitation  to speak at this session.  His primary research focus is quantifying and understanding sea level variability, especially trying to separate natural climate variability from anthropogenic climate change.  Hope to see you there!

Taking the train to the AAS meeting

posted Jan 2, 2015, 11:29 AM by Ramin Skibba   [ updated Jan 4, 2015, 10:17 AM ]

As James wrote in the previous blog post, you're welcome to join us for our Special Session at the AAS meeting next Wednesday (7th January) at 12:30-14:00 in Room 4C-3.  We'll be starting the new year with ideas and plans for addressing climate change issues in class and with the media.

We encourage anyone who is interested in the Sustainability Committee to contact us and get involved.  We will post resources on this website for teaching and discussing climate change with journalists.

It's important for astronomers to try to make observatories, telescopes, university department buildings, and computer centers as energy efficient as possible, but our largest environmental impact and carbon footprint comes from airplane flights to meetings, conferences, workshops, etc.  According to a New York Times article, air travel emissions account for about five percent of global warming, and that fraction is projected to rise significantly as the volume of air travel is increasing much faster than gains in flight fuel efficiency.

It would help this situation to develop better resources and technologies for videoconferencing and remote observing, and these are areas where we should continue to make improvements.  In addition, long-distance travel can be difficult for some people, such as for those with families and those in relatively remote locations, and videoconferencing and webcasts can make conferences more accessible to more people.

Nonetheless, long-distance travel is sometimes necessary, including for early-career scientists who need to advertise their work and network at conferences.  I joined the Sustainability Committee in 2014, and one thing I am trying to do and trying to encourage others to do is to take more trains.  In the US, long-distance trains can be very useful depending on where one wants to travel.  They are not always the fastest mode of transportation, but they are comfortable, convenient, have nice views, and have wireless access if you need to work.  And importantly, they save energy.

I work at the University of California, San Diego, and I'm taking the train up the Pacific coast to Seattle via LA, the Bay Area, Sacramento, and Portland.  I'm traveling nearly 1500 miles (2400 km)--nearly the entire distance from the southern to northern border of the US.  As I wrote on on my own blog, Amtrak trains expend 1,600 BTUs of energy per passenger per mile, while planes use 2,500 and cars use 3,900.  Trains are much more energy efficient than planes, cars, and buses, and by not flying to Seattle, I'm saving tons of carbon dioxide emissions.  This is just a start, but I am trying to view flying as a luxury or necessary evil that I will avoid and reduce when possible.

In any case, I'm excited to be part of the new and improved Sustainability Committee, and if you're interested, join us at the AAS and make an effort in 2015 to reduce your and your institution's carbon footprint.

Sustainability Committee Rides Again!

posted Dec 6, 2014, 3:54 PM by James Lowenthal

After a brief respite and following excellent leadership by former chair Kartik Sheth, the Sustainability Committee has been reconstituted (see About Us for new membership).  We will hold a Special Session at the Seattle AAS meeting in January: 

12:30 - 2:00, Wed. Jan 7

We'll focus on two topics: 1. teaching climate change in Astro 101; and 2. communicating about climate change with the media and with climate skeptics/deniers.  For part 2, we'll do a role-play exercise in which we stage a mock debate.  Join us, and bring your best debate skills!

Traveling Virtually

posted Aug 13, 2013, 8:09 AM by Bryan Miller   [ updated Aug 13, 2013, 8:14 AM ]

The Sustainability Committee has posted an article, Traveling Virtually, to the AAS web site with advice about how to work effectively in virtual environments, especially for meetings and observing, so that astronomers can reduce travel, make the best use of ever tighter funding, and help reduce astronomy's per capita carbon footprint.
Please post additional ideas or experiences here!

Breathe in, breathe out...

posted Apr 9, 2013, 9:47 AM by Bernadette Rodgers

Time to resuscitate this blog!  The AAS Sustainability Committee, after a short sabbatical, has renewed its commitment to its mission, and with it, to maintaining this web space.  One way we will do this is by significantly increasing the traffic on this blog, and by significantly, I mean at least one blog post per month (I know, crazy, huh?).  So don't worry, still well within the safe range for your inbox, but somewhere above "non-existent". 

And we'd love to have some help.  So if you'd like to be a guest blogger, please add a comment or send a message to to volunteer.  Any topic related to our missionis welcome. 

Please watch this space for more posts coming soon, and do get in touch if you have something to say.  We look forward to hearing from YOU!  Thanks!

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