Finding my Way to Low-Cost Sensors at an Immense Research Gathering: The EGU2025

Last week, I had the chance to attend one of the world’s largest and most prestigious conferences in the field of atmospheric sciences: the EGU General Assembly. Organized by the European Geosciences Union (EGU), this annual event covers not only atmospheric sciences but an extraordinary range of disciplines — no matter if you’re interested in ocean health, space weather, earth quakes or climate change: The EGU covers all of this and more. Over 18,000 (!) scientists from more than 120 countries gathered in Vienna to share their latest scientific insights, with up to 100 sessions running in parallel at any given moment!

The Sheer Size of EGU2025

Just to give a sense of scale: Atmospheric Sciences is only one of 22 divisions represented at EGU. Even within this single field, there are six major subtopics (such as Atmospheric Composition, Chemistry and Aerosols or Methods and Techniques). Each of these subtopics included anywhere from 10 to 40 sessions. Sessions can last from a few hours to multiple days and may feature over 50 oral presentations and posters.

This means that in the Atmospheric Sciences division alone, EGU2025 hosted over a hundred sessions and thousands of scientific contributions!

The Rising Importance of Low-Cost Air Quality Monitoring

A clear emerging research trend was the rapid growth of interest in low-cost air quality monitors. What began just a few years ago as a niche topic with a handful of attendees has now become one of the most high-profile sessions in the atmospheric sciences track.

The session “Low-cost air quality sensors: challenges, opportunities, and collaborative strategies across the world” filled a large lecture hall and spanned an entire day—a clear sign of the importance of this field. This development stresses the increasing value of affordable, scalable monitoring technologies in the fight against air pollution, especially in communities lacking traditional infrastructure.

A great Thank You goes to Sebastian Diez, Erika von Schneidemesser, Miriam Chacón-Mateos, John Richard Hizon, and Kwabena Fosu-Amankwah for putting together such a successful and timely session.

Challenges in Low-Cost Sensor Research

While watching the presentations and posters on low-cost air quality monitoring, a few recurring themes and challenges stood out to me (among others):

• Standardized data processing and calibration: Despite the rising use of small air quality sensors, consistent and transparent methods for processing and calibrating air quality data are still lacking. A clear need for a standardized procedure—usable and adoptable by the entire community—emerged during the discussions. While there have already been a few promising efforts in this direction, one key challenge is that some of these standards are not freely accessible, limiting their wider adoption.

• Data sharing and interoperability: Making the most of sensor data requires shared formats and metadata standards. Without these, collaboration becomes difficult and the broader impact of datasets is limited. A move toward open, structured, and well-documented data will be critical for advancing the field.

• Public communication and engagement: Scientific data must be translated into accessible insights. A recurring question was how to communicate AQ data in ways that empower people to act. Examples included outreach in schools (e.g., Clean Air Living Matters from the University of Reading) and creative visual tools like the Danish Tech Institute’s “birdie"—a figurine that dramatically “collapses” when indoor CO₂ reaches unsafe levels.

Sharing Our Research at EGU

As part of this session, I presented some of AirGradient’s ongoing research during the poster session. My focus was on alternative calibration methods for communities that don’t have access to high-grade reference equipment or technical calibration expertise. You can check out the poster here.

The poster attracted a lot of attention—so much so that what was supposed to be a two-hour session extended well into lunch as discussions continued. It was exciting to see such genuine interest and engagement around community-driven monitoring approaches.

The Small Sensor “Roundtable”

The final highlight of my week was a smaller-scale, focused meeting on small sensors for atmospheric science, organized by the Allin Wayra group. Amidst the fast-paced conference schedule, this session offered a calm and open space where the core community of low-cost sensor researchers could step back, reflect, share ideas, and strategize.

We discussed how to maximize the impact of low-cost air quality monitors and discussed their challenges—such as limited access to standardized calibration procedures, as mentioned earlier. Many thanks to Allin Wayra for creating this valuable opportunity for deeper dialogue and connection.

Looking Ahead

All in all, my days at EGU were a fantastic experience. I came away with valuable insights and the latest developments in the field of low-cost air quality monitors. I will integrate this new knowledge into AirGradient’s upcoming work.