Space-based observations of CO2 and CH4: From its early days towards monitoring of anthropogenic greenhouse gas emissions
Prof. Dr. Hartmut Boesch
Prof. Dr. Hartmut Boesch
INF 229, SR 108/110

The rise in greenhouse gas concentrations CO2 and CH4 in the atmosphere due to human activities are the main drivers for the increase in global surface temperatures. Human-induced greenhouse gas emissions are embedded in natural carbon and methane cycles that are responding to climatic fluctuations and change. To limit global warming to manageable levels, many countries have pledged at the Conference of Parties in 2015 in Paris (Paris Agreement) to reduce their greenhouse gas emissions with the goal of reaching net–zero carbon emissions in the second half of the century. To reliable predict the future state of our climate system requires not only a good understanding of the trajectory of anthropogenic emissions but also the evolution of fluxes in and out of the land and marine ecosystems.

Global observations of atmospheric CO2 and CH4 concentrations space are now available for more than 20 years thanks to the pioneering missions SCIAMACHY, OCO-2 and GOSAT providing important top-down constraints on regional-scale surface fluxes to evaluate and improve bottom-up models especially in regions with poor coverage of surface networks. The first European mission designed with anthropogenic emission monitoring in mind is the Copernicus CO2 Monitoring (CO2M) mission which will form the space component of the European Monitoring and Verification system with the goal of tracking progress towards emission reduction targets and for verifying the effectiveness of mitigation policies

In this presentation, I will introduce the key concepts for satellite observations of CO2 and CH4 and present examples how we use current satellite missions to diagnose and quantify regional surface fluxes of natural and anthropogenic sources. I will discuss recent developments in hyperspectral remote sensing to observe individual emission sources with high spatial resolution. The presentation will end with an outlook towards the upcoming CO2M mission.