Regional climate downscaling (RCD) techniques, including both dynamical and statistical approaches, are being increasingly used to provide higher-resolution climate information than is available directly from contemporary global climate models. The techniques available, their applications, and the community using them are broad and varied, and it is a growing area. It is important however that these techniques, and the results they produce, be applied appropriately and that their strengths and weaknesses are understood. This requires a better evaluation and quantification of the performance of the different techniques for application to specific problems. Building on experience gained in the global modelling community, a coordinated, international effort to objectively assess and intercompare various RCD techniques will provide a means to evaluate their performance, to illustrate benefits and shortcomings of different approaches, and to provide a more solid scientific basis for impact assessments and other uses of downscaled climate information.

The WCRP views regional downscaling as both an important research topic and an opportunity to engage a broader community of climate scientists in its activities. The Coordinated Regional Climate Downscaling Experiment (CORDEX) has served as a catalyst to achieve this goal.

The first conference International Conference on the Coordinated Regional Climate Downscaling Experiment – CORDEX – was held in Trieste, Italy 21-26 March, 2011. It was devoted to a review of the status and main issues of the CORDEX initiative over the various CORDEX domains. Special sessions were devoted to the Africa domain and to the assessment of the first multi-model CORDEX simulations over this region.

As demonstrated at the second International Conference on Regional Climate – CORDEX 2013 held on 4-7 November in Brussels, Belgium, and co-sponsored by WCRP, the European Commission and IPCC, the CORDEX concept had gained maturity and was showing strong buy-in from the science community and VIA practitioners. To meet stakeholders’ expectations the conference outcomes were followed-up  to improve the experimental framework so as to improve the CORDEX framework.

At the third International Conference on Regional Climate – CORDEX 2016 held on 17-20 May in Stockholm, Sweden, and co-sponsored by WCRP, SMHI, Bolin Centre, FORMAS, ECRA, ESA, EUMETSAT, and APN, it was shown that CORDEX has contributed vastly to the development and production of regional climate data and information.

Regional climate information is more than ever needed for decision-making on societal issues such as vulnerability and adaptation to a changing climate with weather/water extremes. Thus in order to pursue the use of knowledge and products the fourth International Conference on Regional Climate-CORDEX 2019 was held in Beijing, China on 14-18 October 2019. The conference brought together international regional climate information providers and users.

The fifth International Conference on Regional Climate-CORDEX 2023 was held in Trieste, Italy, Pune India, and online, 25-29 September 2023. The conference brought together the international regional climate research community, focusing on high resolution climate information and its applications to vulnerability, impacts and adaptation and the full spectrum of potential end users of regional climate information. It promoted the CORDEX vision to advance and coordinate the science and application of regional climate downscaling through global partnerships.


The CORDEX Framework

Addressing climate information needs at the regional level: the CORDEX framework

WMO bulletin (July 2009)