Global Environment

Earth observations using the Greenhouse gases Observing SATellite (GOSAT) series


What is the Greenhouse gases Observing Satellite (GOSAT) series?

 The mission objective of the GOSAT series of satellites is to contribute to the development of climate change science and policy. It consists of GOSAT (launched in 2009) and GOSAT-2 (launched in 2018), both of which are currently in operation, and GOSAT-GW (to be launched in 2024), which is currently under development.

Greenhouse gases Observing SATellite : GOSAT


 The greenhouse gases observing satellite mission is jointly conducted by the Ministry of the Environment, NIES, and JAXA in accordance with the Basic Plan for Space Policy to help solve global issues and realize a safe, secure, and prosperous society.

Three-party Joint Mission


・GOSAT (nicknamed "IBUKI") is the world's first satellite dedicated to observing the concentrations of carbon dioxide and methane, two major greenhouse gases, from space. Since its launch on January 23, 2009, 14 years ago, the observations are ongoing.

・Analysis of GOSAT observational data provides insights to the global distribution of carbon dioxide and methane, their absorption and emission amounts, and their seasonal and interannual variations.

・This information is used to contribute to climate change science as well as to climate change policy.

・The "2019 Improvements to the IPCC Guidelines for Calculation of Greenhouse Gas Emissions and Absorption (2006)" which was approved at the 49th IPCC General Assembly meeting held in Kyoto, Japan in 2022, introduced many examples of GOSAT data applications and provided expectations for the GOSAT-2 mission.

・In the "IPCC Sixth Assessment Report (AR6) Working Group 1 (WG1) - Natural Scientific Basis", published in August 2021, monthly-averaged GOSAT data on atmospheric concentrations of carbon dioxide and methane were included among other global datasets demonstrating increases in greenhouse gas concentrations and changes in the rate of increase in the global atmosphere.

・In March 2020 the Ministry of Environment established a study team to discuss how to prevent the GOSAT series from becoming space debris and remaining in orbit indefinitely once the operational period concludes. The team was tasked with examining the issue and making recommendations. In particular, more than 10 years after its launch, a decommissioning plan for GOSAT-1 was identified as a priority. An interim report was compiled in October 2020 and discussions are ongoing with the relevant parties.

(The Ministry of the Environment's Approach to the Space Debris Problem Japanese version English version


・GOSAT-2 (nicknamed "IBUKI-2"), the successor to GOSAT, was launched on October 29, 2018, and began regular operations in February 2019.

・Compared to GOSAT, GOSAT-2 improves the accuracy of carbon dioxide and methane concentration observations with higher-performance onboard sensors. In addition, GOSAT-2 has increased functionality with the ability to concentrate on large emission sources such as major cities and to automatically locate and observe cloud-free areas.

・In order to further improve the ability to identify carbon dioxide emitted by human activities, simultaneous observations of carbon monoxide are also collected.

・GOSAT-2 aims to contribute to the implementation of nationally determined contributions (climate change measures) under the Paris Agreement and, in particular, the first Global Stocktake in 2023.



・The third satellite of the GOSAT series is currently under development for launch in JFY2024 as a joint satellite for the GHG Observation Mission (Ministry of the Environment and the National Institute for Environmental Studies) and the Water Cycle Change Observation Mission (JAXA). The satellite is named "Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW)" to represent the two missions.


・GOSAT-GW aims to carry on the GHG observations as the successor to the missions of GOSAT and GOSAT-2,

(1)Continuous monitoring of carbon dioxide and methane concentrations in the global atmosphere

(2)Ensuring the transparency of countries' greenhouse gas inventory reporting under the Paris Agreement

(3)Refine climate change projections by monitoring large-scale emission sources.


Results of global greenhouse gas observation by GOSAT

Significance and characteristics of GOSAT observations

・Several meteorological organizations around the world, including the World Meteorological Organization (WMO), have calculated and published global average concentrations using ground-based observational data at the earth's surface. However, because the concentration of carbon dioxide varies with altitude, concentration data from ground stations alone does not represent the overall concentration of the Earth's atmosphere.

・In contrast, GOSAT does not measure the surface concentration of carbon dioxide, but rather the total amount of carbon dioxide in the atmosphere from the surface to the top of the atmosphere. The future concentration of carbon dioxide projected in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) is the average concentration in the "total atmosphere".

・In order to calculate and predict the risk of global warming due to future increases in greenhouse gases, it is important to calculate the average concentration of greenhouse gases over the entire planet, and it is essential to obtain an average that is representative of the "total atmosphere".

Observation Results  ※Links to external webpages


Related Materials and Pages

GOSAT Series Introduction Materials   Japanese version English version

GOSAT Series Special Report   Japanese version English version





Press release by the Ministry of the Environment

















Press releases from the project’s partner agencies

(since November 2018)








Website Links for the project’s partner organizations

National Institute for Environmental Studies,Japan (NIES)

GOSAT Project
GOSAT-2 Project
GOSAT-GW Project

>>>If you would like to use GOSAT series data, please click here (user registration is required).

GOSAT Data Archive Service 

GOSAT-2 Product Archive 

Japan Aerospace Exploration Agency  (JAXA)

Space Technology Directorate I  - GOSAT Project
Space Technology Directorate I  - GOSAT-2 Project
Space Technology Directorate I  - GOSAT-GW Project
Earth Observation Research Center - GOSAT HP