The first 'Exploratory' workshop, has been held on May 1st, 2013 focusing on short presentations of current capabilities, aspirations and identification of barriers to progress – each participating group was asked to present "what we do now, how we do it, what we'd like to do, where are the barriers?". As well as formal presentations, sufficient time has been allowed to permit detailed discussions in smaller groups. The outcome of this first workshop had a focus on establishing the network and generating a shared research agenda.

The second 'Consolidation' workshop took place on Oct 31st 2013 in York and featured presentations suggesting possible solutions to (common) issues and aspirations identified in the first workshop, fitness for purpose of new or current technologies, and outlines of possible future research needs. This workshop helped to identify where progress could be made. A key outcome of this second workshop were roadmaps for joint grant proposals emerging from the network, as well as specific activities between network partners.

The main output of the global challenge network on tropospheric ozone was the compilation of 5 'Fact Sheets', summarising the current knowledge and future challenges related to monitoring, modelling and effects assessment of tropospheric ozone pollution. In addition, the preparation for and organisation of the Quadrennial Ozone Symposium 2016, which will be held in Edinburgh from 4-9 September 2016 has been a key success of the network, with several network partners contributing as organisers, session convenors or contributing oral or poster presentations. Several side events will be held at the QOS 2016, bringing together the global ozone research community.