Global Climate Monitoring Gets Boost as Three Key Terrestrial Networks Gain GCOS Accreditation

Terrestrial networks play a vital role in measuring Essential Climate Variables (ECVs)—key indicators used to monitor climate change and its impacts on land, water, and ice systems.

In a major step toward strengthening global climate monitoring, three critical terrestrial observation networks have been officially accredited as Global Climate Observing System (GCOS) Affiliated Networks, enhancing the world’s ability to track climate change across land systems.

The newly accredited networks—Global Terrestrial Network for Glaciers (GTN-G), Global Terrestrial Network for Permafrost (GTN-P), and the International Soil Moisture Network (ISMN)—join a select group of global systems providing essential climate data.

Strengthening the Backbone of Climate Observation

Terrestrial networks play a vital role in measuring Essential Climate Variables (ECVs)—key indicators used to monitor climate change and its impacts on land, water, and ice systems.

These variables are crucial for understanding:

• Interactions between the hydrosphere and cryosphere

• Long-term changes in land and water systems

• How terrestrial processes both influence and respond to climate change

The accreditation recognizes the networks’ scientific value and aims to improve their long-term sustainability and global coordination.

Addressing Gaps in Global Coverage

Despite their importance, many terrestrial networks face challenges, including:

• Uneven global coverage and representation

• Limited long-term funding and institutional support

GCOS affiliation is intended to strengthen these systems by ensuring they meet key standards, including:

• Monitoring ECVs at a global scale

• Providing open and freely accessible data

• Adhering to GCOS Climate Monitoring Principles

Glacier Monitoring: A Century of Climate Evidence

The Global Terrestrial Network for Glaciers (GTN-G) is among the most established climate observation systems, with monitoring efforts dating back to 1894.

It tracks critical glacier-related indicators:

• Glacier area

• Elevation change

• Mass change

Operated by leading institutions including the World Glacier Monitoring Service (WGMS) and NASA-supported initiatives, GTN-G combines in-situ measurements, satellite data, and modelling to deliver one of the longest records of climate-driven change.

Glaciers remain one of the most visible indicators of global warming, making GTN-G’s data vital for climate science and policy.

Permafrost Monitoring Expands Global Reach

The Global Terrestrial Network for Permafrost (GTN-P) monitors frozen ground across high latitudes and mountainous regions.

Key measurements include:

• Permafrost temperature

• Active layer thickness

Coordinated by Germany’s Alfred Wegener Institute, the network draws on contributions from 40 national correspondents across 26 countries, reflecting a highly collaborative global effort.

In January 2026, GTN-P launched a new data platform, improving accessibility and integration of permafrost data worldwide.

Soil Moisture: A Critical Yet Under-Observed Variable

The International Soil Moisture Network (ISMN) provides the world’s most comprehensive in-situ soil moisture dataset:

• Data from 3,200 monitoring stations globally

• Time series spanning up to 45 years

• Open-access platform for researchers and policymakers

Soil moisture is a key ECV influencing agriculture, drought prediction, water cycles, and climate modelling, yet remains under-observed in many regions—particularly in the Global South.

Expanding a Global Climate Data Ecosystem

With these new additions, the networks join previously accredited systems such as:

• Baseline Surface Radiation Network (BSRN) (accredited in 2022)

• Global Terrestrial Network for Rivers (GTN-R) (accredited in 2025)

Together, these systems form a comprehensive global observation infrastructure, supporting climate science, early warning systems, and policy decisions.

Why This Matters

Reliable, long-term climate data is essential for:

• Tracking global warming and environmental change

• Improving climate models and forecasts

• Informing adaptation and mitigation policies

• Supporting international agreements such as the Paris Agreement

By strengthening terrestrial observation networks, GCOS is helping ensure that climate decisions are grounded in robust, transparent, and globally consistent data.

Looking Ahead

The accreditation of GTN-G, GTN-P, and ISMN signals growing international recognition of the need to invest in climate observation infrastructure, particularly as climate impacts intensify.

However, experts caution that continued progress will depend on closing data gaps, securing long-term funding, and expanding monitoring coverage, especially in underrepresented regions.

As the climate crisis deepens, these networks will play an increasingly critical role in understanding—and responding to—rapid environmental change.