IN FOCUS: The Global Impact of GRSS REACT

By Joanne Van Voorhis

GRSS REACT (Remote sensing Environment, Analysis and Climate Technologies Technical Committee) supports the efforts of geoscientists and engineers around the world who focus on the impact of climate change on our environment. It provides a global venue for exchanging ideas and sharing knowledge while supporting the advancement of remote sensing and Earth Observation (EO) technologies, environmental monitoring, and geospatial technologies for sustainability and disaster management in general. REACT aims at advancing science, defining requirements for science driven mission concepts and data products in the cryosphere, biosphere, hydrosphere, atmosphere as well as the geosphere.

Action Oriented with a Global Focus

“REACT channels the start of the art research in the field of geoscience and remote sensing into action-oriented analyses, particularly in the context of promoting the adoption of climate technologies,” explains Dr. M. Adnan Siddique, who leads the Remote Sensing and Spatial Analytics Lab, ITU, Pakistan, and is the current REACT Technical Committee Chair. He believes the world needs nature-positive solutions, with less red tape that prevents progress. “While it is not in REACT’s mandate to take up challenges at the level of governance and policy, it does serve to provide a supporting scientific platform and encourages an actionable path for adoption of relevant technologies,” he adds.

Priorities and Focus

“Achieving REACT goals requires a collective effort, with members and volunteers playing a vital role in making a difference,” explains Dr. Irena Hajnsek, ETH Zürich, and founder of the REACT Technical Committee. “In order to set priorities, our committee has identified several local “focus” areas where remote sensing and EO can help save lives and support the environment and ecosystems,” Hajnsek says. 

One such focus area is “Urban Resilience,” which promotes efforts to harness EO and big data analytics to track urban heat patterns over time, highlight inequalities, and support climate adaptation in urban environments. The “Risks in High Mountain Asia” focus area is concerned with the risk of disasters like flash floods, landslides, debris flows, and rockfalls, which threaten ecosystems and communities in this region which is home to the largest amount of vulnerable ice mass outside the polar regions. Flooding in Africa is another focus area, motivated by the high risk of flooding in those cities in the region without strong flood defenses or efficient drainage systems. The “Pacific Islands and Territories” focus area was identified because although Pacific Island nations have had the least involvement in causing climate change, they are expected to experience the most extreme consequences. And, the “Agriculture and Food Security” focus area was identified to help provide accessible EO data to those with little EO experience to track crop health, planting trends, and other risks to support sustainable agriculture and food security worldwide. Other focus areas are expected to be added over time.

Tools and Events Encourage Collaboration

“The REACT committee is reaching out to audiences via its publications, workshops and schools, encouraging all to contribute by sharing their knowledge, expertise and even datasets,” says Siddique. “Occasionally, the committee also reaches out to researchers and change-makers from the public policy domain, apprising them of the latest climate technologies that can bring out sustainable solutions to pressing environmental problems,” he explains.

GRSS REACT encourages members to collaborate on these and other initiatives through many venues including online and in-person meetings and events. For example, GRSS REACT held a four-day workshop focused on remote sensing for hazard monitoring and modeling in High Mountain Asia in Kathmandu, Nepal in May. This workshop emphasized glacial ecosystem monitoring and hydrological modeling with state of the art remote sensing. Participants explored key technologies, including synthetic aperture radar (SAR), SAR interferometry, and SAR polarimetry. REACT also sponsored a tutorial in October on SAR Technology and Applications for Sustainability at the 9th Asia-Pacific Conference on Synthetic Aperture Radar in Japan. The program included presentations on the SAR Polarimetry and PolInSAR, offering insights into advanced SAR-based methods involving polarimetric observables for environmental applications. In the context of protection of life below water (SDG 14), the tutorial also included a talk on the detection of oil spills in the oceans using Sentinel-1 SAR images.

2026 promises even more outreach to connect members and to help facilitate problem-solving. Chair Siddique, with the support of the committee, intends to initiate a GRSS REACT panel discussion series in 2026 to provide an online platform where stakeholders can contribute to environmental issues such as flooding and other issues. “We will focus on urban resilience to floods, how accelerating cryosphere-origin melts are ramping up the challenges related to flooding in urbanized valleys, and how food insecurity is impacted,” he explains.

Making an Impact Now and into the Future

“The world today is marred with not only economic inequality, but also inequality in terms of the requisite knowledge that is foundational to saving our environment. Several developing or undeveloped countries lack the agency to tackle ongoing environmental threats, some of which are natural while others anthropogenic,” explains Siddique. “REACT is particularly vital now, given that it gathers the relevant scientists and practitioners as volunteers joining hands to offer the knowledge and expertise to people across the globe. REACT achieves these goals via its webinars, workshops, schools and competitions,” he adds.

The global impact of REACT is expected to be more and more relevant over time. “The world needs nature-positive solutions to the growing environmental issues. Technology has to be translated faster into deployment, so that the socio-economic problems are addressed quicker. REACT is a purpose-oriented entity that will help us achieve these aforementioned objectives,” says Siddique.