View of carbon masts above the trees at BIFoR FACE

The recent visit of UK Foreign Secretary, James Cleverley, to an Amazon Forest research site has delivered some eye-catching photo-opportunities but also much more. The associated announcement of £7.3 million of funding, the UK half of the largest UK-Brazil science cooperation to date, propels a global effort to understand how forests will respond in the high-CO2 air of the future.

Forest Free-Air CO2 Enrichment (FACE) facilities, like that visited by the Secretary of State, are rare and very expensive. The Birmingham Institute of Forest Research run BIFoR FACE in central England and Western Sydney University run EucFACE in Australia. Now Amazon FACE, run by the Amazonian research agency, INPA, and the University of Campinas, is funded to completion and should begin to operate by the end of 2023. Each facility exposes patches of mature forest to air containing extra CO2, about a third extra, without the use of walls or roofs. The patches then sit in an atmosphere that is expected to be the planetary norm by mid-century.

By comparing these ‘future forest’ patches to nearby control patches bathed in today’s air, scientists study how forest communities of plants, animals (especially invertebrates), and microbes react. The answers are not straightforward. Leaves bathed in extra CO2 generally increase photosynthesis, by up to a third in BIFoR FACE, taking carbon into the trees. This increased photosynthesis is called ‘CO2 fertilisation’.

Only patient and painstakingly detailed observations at FACE sites across the world can determine how different ecosystems respond to CO2 fertilisation. Without the experimental benchmarking and process insights supplied by forest FACE facilities, the computer models projecting our climate are shooting in the dark.

Professor Rob MacKenzie - Founding Director, Birmingham Institute of Forest Research, University of Birmingham

Although extra carbon goes in, it need not be stored if the forest community ‘breathes out’ the CO2 it takes in, as has been found to occur at EucFACE. Such a ‘null result’ is far from unimportant. Faster carbon cycling under the extra CO2 changes the cycling of water or nutrients and so can affect the forest profoundly. Only patient and painstakingly detailed observations at FACE sites across the world can determine how different ecosystems respond to CO2 fertilisation. Without the experimental benchmarking and process insights supplied by forest FACE facilities, the computer models projecting our climate are shooting in the dark.

It's a team game. The Brazilian-led Amazon FACE science community includes scientists from the University of Birmingham, the Met Office, and several other UK organisations, but also scientists from Europe and north America. The three FACE sites collaborate closely, exchanging scientists, engineers, technical know-how, and early results.

The need to understand the response of the vast tropical rainforest is pressing. Amazon FACE has come into existence through visionary UK-Brazilian funding outside the normal science channels. BIFoR FACE came about through visionary philanthropic giving. In the wake of global CO2 shortages, BIFoR FACE has partnered with Wykes Engineering to find a new supply, winning a National Sustainability Award along the way. From their funding to their engineering, FACE facilities have found new ways of doing things.

For the Birmingham-Brazil axis specifically, two new initiatives will strengthen teamwork in all areas of environment and climate justice, including the FACE collaboration: a newly announced Brazil Institute and the Chico Mendes Chair of the CAPES Foundation of the Brazilian Ministry of Education, both situated at the University of Birmingham. New solutions for unprecedented times; the work of many hands which must now be sustained for many years.