Center for Global Environmental Research,NIES, JAPAN

11/11/2025

COP30 has officially opened in Belém, Brazil.

Dr. Hiroshi TANIMOTO, Director of the Earth System Division at NIES, will present on “The GOSAT-GW greenhouse gas observation mission and the planning of the Japan GHG Center” at the seminar titled “Promoting the Use of GOSAT Data in Climate Science Communication and Business”.

For more details, please visit https://www.copjapan.go.jp/cop30en/seminar/1701/

About COP30 Promoting Use of GOSAT Data for Climate Science Outreach and Business Applications ｜ COP30 JAPAN PAVILION

09/09/2025

The 2022 eruption of the Hunga Tonga–Hunga Haʻapai volcano released a large amount of water v***r and a moderate amount of sulfur dioxide into the stratosphere, triggering noticeable changes in the climate system. To study these effects, an international project called HTHH-MOC (Hunga Tonga–Hunga Haʻapai Volcano Impact Model Observation Comparison) was launched as a limited-term focused cross-activity with a duration of 3 years, led primarily by the University of Colorado and NOAA.

This project is focused on evaluating global chemistry–climate models regarding the following three science themes: (1) plume evolution, dispersion, and large-scale transport; (2) impacts on stratospheric chemistry and the ozone layer; and (3) radiative effect from the eruption and surface climate impacts.

The project will not only benefit the Hunga Impact assessment but also benchmark the model performance in simulating stratospheric explosive volcanic eruption events and stratospheric water v***r injections.

Among the experiments recommended for this project, only Exp2b was conducted using the CCSRNIES-MIROC3.2 chemistry-climate model at the National Institute for Environmental Studies. Exp2b is an experiment designed to investigate the chemical effects on trace species concentrations resulting from volcanic eruptions, by prescribing temperature, horizontal wind, volcanic aerosol loading, and water v***r.

For more details, please read “Hunga Tonga–Hunga Ha′apai Volcano Impact Model Observation Comparison (HTHH-MOC) project: experiment protocol and model descriptions”
https://doi.org/10.5194/gmd-18-5487-2025

22/08/2025

A new study led by researchers at the National Institute for Environmental Studies, Japan Agency for Marine-Earth Science and Technology and The University of Tokyo reveals that if no efforts are made to stop climate change, the dieback of the Amazon rainforest may start within the 21st century.

The Amazon is the world's largest rainforest. It harbors immense biodiversity and plays a crucial role in the global climate system. The Amazon is widely recognized as a major climate tipping element. Continued deforestation and climate change could cause the Amazon to shift from rainforest rich in biodiversity to a degraded savannah-like ecosystem.

Researchers assessed long-term changes in the Amazon rainforest from the present through the year 2300 using the state-of-the-art Earth System Models, which informed the IPCC’s Fifth and Sixth Assessment Reports. This research defined “dieback” as severe loss of photosynthetic activity by the end of the 23rd century compared to the 19th century in areas that were originally highly productive, under high-emission scenarios. The scientists then analyzed the climatic and ecological conditions under which such drastic shifts could occur.

Most models agree that the Amazon dieback could begin as early as the 21st century, triggered by extreme conditions—large increases in temperatures, decreases in precipitation and intensified by land-use change from forest to agricultural lands. These findings highlight the urgent need to limit greenhouse gas emissions. The lead author Dr. Irina Melnikova also cautions that future research should focus on improving the representation of ecological processes in models to better anticipate the risks. Protecting the Amazon requires coordinated international action, integrating climate mitigation, sustainable land management, and conservation strategies.

For more details,
Please read
- the Press Release https://www.nies.go.jp/whatsnew/20240820/20250820-e.html
- “Amazon dieback beyond the 21st century under high-emission scenarios by Earth System models”
https://doi.org/10.1038/s43247-025-02606-5