Orbiting the Climate Crisis

The launch of NISAR, a satellite developed through a collaboration between the US’s NASA and India’s ISRO on July 30, 2025, has attracted widespread attention, particularly from climate policymakers and climate scientists. Space agencies across the world have contributed to the fight against climate change in the past as well. Other countries with well-developed space programmes include Europe and China. In this article, we look at how space agencies are providing valuable inputs into climate policymaking.

NASA: The Leader

The USA’s NASA is a clear leader in the use of satellites to monitor climate change. Its Earth Science Division operates more than 20 satellites that observe changes in oceans, vegetation cover, forest cover, wildfires, and ice caps. Some of these missions include the Gravity Recovery and Climate Experiment (GRACE), its follow-on mission (GRACE-FO), the Ice, Cloud and Land Elevation Satellite (ICESat) and ICESat-2 missions, as well as Sentinel-6 Michael Freilich and the Jason series of missions, which have documented rising global sea levels since 1992. Some of NASA’s key initiatives include:

The Goddard Institute of Space Studies, which collects surface temperature data of land and oceans through its extensive network of meteorological stations.

Sea-level changes observed from space through various satellite missions.

The National Center for Climate Simulation (NCCS), which focuses on climate and weather prediction.

ISRO: The Indian Space Agency

ISRO maintains a national-level climate change database, and various satellite maps and geophysical products are disseminated through the National Information System for Climate and Environment Studies (NICES) on the Bhuvan portal. Information on 13 geophysical parameters is made available through this portal, including albedo, cloud properties, forest fire regime, land cover, ocean colour, ozone, soil moisture, sea-level pressure, ocean surface currents, snow cover, river discharge (runoff), total alkalinity, and pCO₂. ISRO also has a range of satellites that collect data relevant to the study of climate change. Some of these include:

Oceansat: This series of satellites collects and provides data on sea surface temperature, phytoplankton blooms, and other important parameters for oceanographic and atmospheric studies.

INSAT-3D: This satellite provides information on weather and climate forecasting and is used by agencies such as the India Meteorological Department (IMD) for their forecasts.

TRISHNA (Thermal Infra-Red Imaging Satellite for High-resolution Natural Resource Assessment): This mission, a collaboration with the French space agency CNES, focuses on high-resolution monitoring of Earth’s surface temperature, vegetation health, and water cycle dynamics.

ISRO–NASA Collaboration

The NASA–ISRO Synthetic Aperture Radar (NISAR) is a space satellite launched jointly by the USA’s NASA and India’s ISRO on July 30, 2025, from India. NISAR is unique in that it has two apertures and combines NASA’s L-band radar with ISRO’s S-band radar. The L-band uses long wavelengths to monitor changes beneath thick forests and cloud cover, while the S-band uses shorter wavelengths to observe surface features such as water bodies and agricultural land. The satellite has been placed in a sun-synchronous orbit and will provide images of the Earth every 12 days. NISAR will observe changes in ecosystems, ice mass, vegetation biomass, forest cover, groundwater, and sea-level rise, as well as natural hazards including earthquakes, tsunamis, volcanoes, and landslides. It will be a valuable addition to global efforts to monitor climate change.

European Space Agency (ESA)

Like NASA and ISRO, the European Space Agency also operates several satellites involved in Earth observation and the collection of data on various climate indicators. ESA undertakes climate modelling, provides critical datasets, and tracks greenhouse gas emissions. The Copernicus programme operates the Sentinel satellite missions, which provide continuous data on the state of land, forests, and oceans.

Chinese Space Agency (CNSA)

China also operates several Earth observation satellites, such as Ziyuan-3, Haiyang, and Fengyun, which monitor land, oceans, and the atmosphere. China is also the only country to operate a satellite dedicated to monitoring the amount of carbon in the atmosphere. The CNSA collaborates with the ESA through the Dragon programme to monitor the environment, agriculture, floods, and air quality, and also undertakes forest mapping. Like other space agencies, CNSA conducts research and development and provides important data on key climate variables to various decision-making bodies.

Space agencies of leading spacefaring nations such as the USA, India, Europe, and China are an invaluable resource in the fight against climate change. They provide crucial data that supports science-based decision-making. These satellites act as our “eyes in the sky,” and the vast volumes of data they generate should be used more effectively for international cooperation and for informing mitigation and adaptation decisions, so that countries can reach their net-zero targets at the earliest—because there is no time to be lost.