The first objective of this workshop was to bring together internationally leading mathematical scientists with expertise in: data assimilation; uncertainty quantification; probabilistic numerics’; inference in complex systems and statistical model comparison; and high performance scientific computing.  The second objective was to draw particular attention to success stories and pressing challenges in two fields: the environment and resilient cities.  It was also the aim of the organisers to encourage the UK mathematical community to engage more fully with current activities in metrology.  The workshop brought together a mix of applied mathematicians, applied statisticians and related researchers from government labs, industry and stakeholder organisations, with an emphasis on accessible presentations that will encourage new research collaboration and knowledge exchange.