NASA Scientist Highlights Advances and Challenges in Tracking Greenhouse Gases

In a recent conversation with Dr. Oksana Tarasova of the Global Greenhouse Gas Watch (G3W), Dr. Lesley Ott, a leading NASA research meteorologist, underscored both the extraordinary progress and the ongoing scientific challenges in tracking greenhouse gas (GHG) emissions. Dr. Ott, who leads carbon cycle modeling efforts at NASA’s Global Modeling and Assimilation Office (GMAO) and serves as project scientist for the U.S. Greenhouse Gas (GHG) Center, described how cutting-edge satellite data, computational models, and international collaboration are transforming our understanding of Earth’s atmosphere.

The Science of a Complex System

For Dr. Ott, the study of greenhouse gases such as carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O) is a compelling puzzle. Each gas interacts with human activity, land use, ocean dynamics, and atmospheric circulation in ways that make their behavior both scientifically complex and operationally vital. NASA’s work in this field integrates Earth observation satellites, numerical weather prediction, and carbon-cycle science to create actionable data products that can guide policy and climate action.

“The ultimate challenge is to get the right answer for the right reason,” Ott explained, highlighting the need for models that accurately represent the real-world processes driving emissions and removals.

A Decade of Breakthroughs

Over the past decade, rapid advances have reshaped greenhouse gas monitoring.

• Satellite Improvements: NASA’s Orbiting Carbon Observatory (OCO) series has revolutionized measurement quality, reducing biases between land and ocean data.

• Data Assimilation: Methods for blending observations with models have become powerful enough to integrate into operational forecasting systems, producing reliable, near-real-time emission estimates at city and state levels.

• Hybrid Computational Grids: Innovative modeling approaches now focus computing power where emissions are most dense, such as urban and industrial areas, improving efficiency without sacrificing detail.

• Better Prior Data: More accurate emissions inventories and refined land and ocean carbon models now provide stronger baselines for atmospheric inversion models that refine estimates using observed concentrations.

These advances have enabled finer-scale GHG tracking, bridging the gap between research and operational decision support.

Persistent Scientific Challenges

Despite progress, challenges remain formidable. GHG modeling requires extreme precision due to the small concentration gradients involved. Disentangling signals from natural and human sources adds further complexity:

• Methane: Numerous small, scattered sources make it difficult to track.

• Nitrous oxide: Observations are sparse, limiting understanding.

• Carbon dioxide: Vertical transport processes such as boundary-layer mixing and convection create significant uncertainty.

Ott stresses the need for more vertically resolved aircraft profiles and expanded ground-based monitoring networks to validate satellite data. Independent validation, she argues, ensures models are not just delivering the “right answer” but doing so for scientifically sound reasons.

The Role of International Collaboration

Ott emphasized that progress depends on global cooperation. G3W, under the World Meteorological Organization (WMO), plays a pivotal role by:

• Defining common standards for GHG modeling.

• Integrating satellite and ground data for more consistent estimates.

• Developing near-real-time operational products for decision-makers.

• Supporting open, publicly accessible datasets that enable transparency and accountability.

The Task Team on Modelling (TT-G3W-Modelling), in particular, is bridging the gap between research and operations, helping national centers produce reliable and comparable flux estimates that policymakers can trust.

WMO Commitments and Tools

Ott pointed to WMO’s work in building capacity across Africa, Asia, and Latin America. Tools like ClimWeb, already in use by 70% of African countries, and initiatives like the Systematic Observations Financing Facility (SOFF) are enabling developing countries to modernize weather and climate services, connect thousands of new monitoring stations, and share real-time data globally. These advances in infrastructure underpin GHG tracking as well as broader disaster resilience.

Looking Ahead: From Science to Action

Dr. Ott envisions a future where modeling centers support not just mitigation—by tracking emissions—but also adaptation, by producing 10- to 30-year climate projections that can inform financial planning, infrastructure, and urban development.

“Climate change is not a 70- to 100-year problem, it’s a now problem,” she emphasized, calling for stronger links between GHG modeling communities and climate prediction systems.

Bridging Research and Real-World Impact

For Ott, the ultimate goal is to move beyond purely academic research and deliver tools that guide real-world decisions. By combining state-of-the-art observations, high-resolution models, and open data sharing, she believes international partners can create a trusted foundation for climate policy.

As G3W evolves, its ambition is clear: to ensure that every government, community, and business has access to the timely, reliable greenhouse gas data needed to act decisively in the face of climate change.