The Australian climate service: Bureau of meteorology and CSIRO contributions to the development of Australia's first national climate change service

The Australian Climate Service (ACS) was established in 2021 to uplift Australian climate science and services to support resilience in the face of increasing impacts from weather and climate extremes. Formed as a partnership across the Federal Government of Australia, it consists of four Partner Organisations: The Australian Bureau of Statistics (ABS), the Bureau of Meteorology (BoM), Commonwealth Scientific and Industrial Research Organisation (CSIRO), and Geoscience Australia (GA) forming a virtual agency. Here, we describe the approach taken by the BoM and CSIRO to develop the climate parts of this service, provide examples of successful delivery, and reflect on lessons learnt. The approach to development borrowed from practices established for seasonal climate prediction services, drawing on the Global Framework for Climate Services and World Meteorological Organization good practice guidance documents. In establishing the service, we found that many concepts and frameworks mapped readily from other timescales. For example, the concept of operations, used for BoM weather services and methods benchmarking, was applied to areas such as climate model selection and calibration. Having modellers, scientists, and climate services staff from multiple agencies collaborate within activities as part of a single value chain was critical for delivery, and readily achievable through an end-to-end program approach.