Environmental Data Centres, such as the Centre for Environmental Data Analysis (CEDA), are facing two interrelated challenges regarding both archive and user data: the data itself is growing rapidly year on year, and the introduction of new storage technology may require a change in workflows for users. Several software packages already exist to exploit this new storage technology, some of which involve re-writing the data into a new file format, which we believe is not suitable for archiving data. This presentation will present a low level library implementation of a data format, developed in conjunction with CEDA and NCAS CMS, that we believe can exploit the new storage technology and remain suitable as an archival data format.