As leading representatives of the environmental and Earth science communities, we are gravely concerned about the proposed closure of the micropalaeontology research group at London's Natural History Museum (see http://go.nature.com/KCppCe).

Micropalaeontology is of considerable strategic and international importance. It underpins biological and geochemical proxy reconstructions of past climates. It is critical for industrial oil and gas exploration. It allows the evolutionary and palaeobiological study of organisms that have the most complete fossil record. The museum's micropalaeontology research group has made acclaimed contributions in all of these areas.

Loss of this expertise will compromise research in these fields and the training of the next generation of industry and research micropalaeontologists.

We accept that the Natural History Museum's researchers are not directly responsible for collections management. But micropalaeontologists are needed to interface with the many professional users of the museum's resources. The use and development of its micropalaeontology collection is likely to suffer in the long term as a result of the research group's closure.

The museum's trustees and director are being forced to respond to funding constraints that will require savings to be made across all departments. Instead of closing a whole research group with such key expertise, we urge the museum's management to produce a more balanced set of proposals that will be less damaging to palaeoclimate research, industrial biostratigraphy and evolutionary palaeobiology (see also http://go.nature.com/Eo4Thh).