Following the visit of Lord Sainsbury to Japan in April 2001, the Met Office's Hadley Centre and NCAS/CGAM have established a collaboration with scientists from the Centre for Climate Science Research (CCSR) at the University of Tokyo and the Earth Simulator Centre, in Yokohama. An ambitious programme of model integrations and climate research is planned on the Earth Simulator - the worlds most powerful computer.

The project's main aim is an Earth System Simulation of the 21st century, at resolutions impossible on less powerful computers and including fully coupled climate-ecosystem-chemistry processes.

Allowing scientists to tackle key scientific and policy questions:

• How will the climate change in the 21st century and how will ecosystem-chemistry interactions affect this change?
• What are the critical feedbacks in the Earth System?
• What will be the wider changes in the life-support systems of the Earth (e.g. stratospheric ozone and UV, tropospheric ozone and human health, water availability)?
• Where are the dangerous thresholds in the Earth system