How you can combat climate change with Astronomers for Planet Earth

May 5, 2023


S. Wagner-Hall. (Photo courtesy of the author.)

by Guest Contributor Sarah Wagner-Hall

A speck in the vastness of the cosmic ocean is what the spacecraft Voyager 1 saw when looking back at Earth from the edge of our solar system, about 3.7 billion miles (6 billion kilometers) from the Sun. The resulting picture of “the Pale Blue Dot” (as Carl Sagan termed it) shows the planet we all live on as a fraction of a pixel among scattered beams of sunlight. This unprecedented image and the resulting emotional impact of our tiny, vulnerable world captures the core mission of Astronomers for Planet Earth (A4E).


Figure 1: “The Pale Blue Dot” is a photograph of Earth taken Feb. 14, 1990, by NASA’s Voyager 1 at a distance of 3.7 billion miles (6 billion kilometers) from the Sun. (Credit: NASA/JPL-Caltech.)
Fig. 1: “The Pale Blue Dot” is a photograph of Earth taken Feb. 14, 1990, by NASA’s Voyager 1 at a distance of 3.7 billion miles (6 billion kilometers) from the Sun. (Credit: NASA/JPL-Caltech.)


Who is A4E?

As I discussed at KIPAC when I visited for an astrophysics research project in 2022, A4E is an international grass-roots movement of astronomy scientists, educators, students, and dedicated amateurs who share their astronomical perspective of Earth with each other, the public, and policy makers. We recognize our planet as not only a unique and fascinating ecosystem, but our only home for the foreseeable future, with the implied directive that we must each step up and do our part to preserve and protect it. 

Since A4E’s founding in 2019, we have provided astronomy-related education about the climate crisis for many educators and multiple outreach events. Furthermore, we are passionate about providing solutions for accessible, international collaborations and innovative meeting formats and we aim to ignite new ideas and concepts in every step of astronomy research, from building telescopes to obtaining and analyzing data to presenting results. As of today the organization includes more than 1,600 members from 75 countries. If you, too, are interested in getting involved and supporting our mission, join A4E for free on our website: 

We are Astronomers for Planet Earth from Astronomers for Planet Earth on Vimeo.

Why an astronomy climate advocacy group?

As scientists we must lead by example and create innovative ways to move forward sustainably. If we do not act according to research outcomes to help preserve our planet, then who will? 

Furthermore, as astronomers we produce significantly more greenhouse gases than the average citizen of Planet Earth through our research. We must take responsibility for the actions that contribute the most to astronomy’s carbon footprint: our travel to conferences and observatories, the ground-based telescopes and the space-based satellites we build and operate, and the computing resources we use to process huge amounts of data. As part of taking more responsibility, A4E members can and do push for transparency around these issues—for instance, by quantifying the carbon footprints of research infrastructure, large meetings, and high-performance computing systems, and developing ways to reduce them (read one example of mitigating the computational energy consumption issue in this KIPAC blogpost from June 2022).

Indeed, astronomy itself must transform for the sake of its own sustainability. Weather extremes affect observatories and long-term funding possibilities for astronomy are uncertain in the face of the political difficulties the climate crises may exacerbate. 

Finally, as the astronomical perspective reveals the uniqueness and fragility of our Pale Blue Dot, it can also inspire us to care for it.

What we do

As an example of what an entirely volunteer group can accomplish, A4E hosted a week-long, fully virtual meeting at the end of 2022 dedicated to raising awareness for sustainability in astronomy and discussing concrete ways to move forward. A total of 576 registrations from diverse backgrounds and wide geographic distribution (see Figure 2) underlines the relevance of the topic for the astrophysics community.


Demographics of the 576 registered participants of the A4E Symposium 2022. (Credit: Wagner, et al., 2022.)
Fig. 2: Demographics of the 576 registered participants of the A4E Symposium 2022. (Credit: Wagner, et al., 2022.)


The symposium covered four key topics:

In addition, representatives from large astronomy and space consortia across the globe, including the National Optical-Infrared Astronomy Research Laboratory, the European Space Agency, and W. M. Keck Observatory, came together to debate concrete plans for sustainable development and decarbonization in a live panel discussion

Our symposium made it clear that members of the broader astronomy community want more guidance on how to get involved. To this end, we launched the A4E Newbie Meetups on every last Friday of the month and we would be delighted to see you there! The next ones are taking place on May 26th at 10am and July 30th at noon. Feel free to reach out to me at <<>> if you are interested in joining.  We hope to include astronomers from currently underrepresented regions such as Africa and Asia as well as engage with more senior scientists and policy makers with ties to funding agencies and decision making.

To learn more about the symposium click the links above, read the report linked below, or check out the A4E Youtube channel!  

How you can help 

There are many active working groups within A4E that need your help. The newest one is focused on collecting and creating educational material about the upcoming solar eclipse within the frame of our mission. Others revolve around general resources and member management, working on a statement on science policy, regional meetups and projects, as well as scientific and educational talks around the world. If you are interested in getting involved in any of these or even have your own ideas for projects you would like to work on, please reach out either directly to me or via the connection details below. 

We advocate for all institutions to form local working committees to analyze their own carbon footprints as a first step in determining how to mitigate their own climate impacts, and have at least one representative interface with the larger A4E organization. If you are in a position to form such a group, you can find several examples available of institutions that have engaged in this process in the references below (for example, see Estimate of the carbon footprint of astronomical research infrastructures).

Facing the climate crisis can make us feel as powerless as a paramecium in the ocean. But look again at that Pale Blue Dot. Our whole world occupies only 0.12 of the 640,000 pixels in that frame and yet it holds creatures who are able to capture its image from a vast distance. Let your support and activism be the fraction of a pixel that turns the picture of our shared future into an inspiring work of art for you and the people around you.

To connect with other sustainability-minded astronomy enthusiasts, you can join A4E via our website: or email us at We would like to encourage all astronomers to join the conversation, share resources, ask questions and state their opinions.We look forward to meeting you!

Learn more   

A4E Youtube channel

A more sustainable future for astronomy 

A path to net-zero carbon emissions at the W. M. Keck Observatory

The ecological impact of high-performance computing in astrophysics 

Forging a path to a better normal for conferences and collaboration

The carbon footprint of large astronomy meetings 

The Future of Meetings

Sustainable High-Energy Physics, Cosmology and Astroparticle Physics (HECAP) - A parallel effort focusing on high energy physics, but applicable to astrophysics researchers, institutions, and instrumentation.