the total carbon column observing network (tcon) is a global network that measures carbon dioxide (co2) and methane (ch4) columns using high-precision spectroscopy. tcon data are archived at https://tccondata.org and include versions such as ggg2020, ggg2014, ggg2012, and ggg2009. the latest retrieval algorithm, ggg2020, was developed by laughner et al. and is based on a new algorithm for generating a priori trace gas profiles. tcon data are crucial for satellite missions monitoring greenhouse gases (ghgs), as they provide ground truth data for satellite observations. however, tcon faces challenges due to the lack of centralized funding. each site principal investigator (pi) must secure funding from local or national agencies, leading to potential delays in data delivery, data gaps caused by hardware failures, and a lack of personnel. despite these challenges, tcon continues to play a vital role in monitoring co2 and ch4 levels globally. the tcon partners are responsible for maintaining and operating the network. tcon data are used by researchers and policymakers to understand and monitor the carbon cycle and climate change. the tcon data archive provides access to a wide range of data, including measurements of co2 and ch4, which are essential for climate research. the tcon network is an important tool for improving the accuracy of greenhouse gas satellite missions. the tcon data are available for download and use by researchers worldwide. the tcon network is supported by various funding sources, and its data are essential for understanding the global carbon cycle and climate change.the total carbon column observing network (tcon) is a global network that measures carbon dioxide (co2) and methane (ch4) columns using high-precision spectroscopy. tcon data are archived at https://tccondata.org and include versions such as ggg2020, ggg2014, ggg2012, and ggg2009. the latest retrieval algorithm, ggg2020, was developed by laughner et al. and is based on a new algorithm for generating a priori trace gas profiles. tcon data are crucial for satellite missions monitoring greenhouse gases (ghgs), as they provide ground truth data for satellite observations. however, tcon faces challenges due to the lack of centralized funding. each site principal investigator (pi) must secure funding from local or national agencies, leading to potential delays in data delivery, data gaps caused by hardware failures, and a lack of personnel. despite these challenges, tcon continues to play a vital role in monitoring co2 and ch4 levels globally. the tcon partners are responsible for maintaining and operating the network. tcon data are used by researchers and policymakers to understand and monitor the carbon cycle and climate change. the tcon data archive provides access to a wide range of data, including measurements of co2 and ch4, which are essential for climate research. the tcon network is an important tool for improving the accuracy of greenhouse gas satellite missions. the tcon data are available for download and use by researchers worldwide. the tcon network is supported by various funding sources, and its data are essential for understanding the global carbon cycle and climate change.