Natural climate variability and long-term climate change operate on timescales that exceed the c.10 day limit of NWP schemes. Such variability and long-term trends constitute important drivers of the new IESMs (see MSP1). Our goal is to de-risk these climate-related drivers on two distinct timescales, that link respectively to operational decisions (e.g. energy hedging) and system-level planning in the industry. This will also provide climate-related risk data to MSP2. On monthly to seasonal operational timescales, we will build on recent improvements in climate model skill for the intra-seasonal prediction of the NAO (Scaife et al., 2014). On longer system-level planning timescales we are concerned with decadal scale trends and the associated increased variability in climate-sensitive RE resources (e.g. spatiotemporal variations in wind, wave, solar and freshwater) that will accompany long-term climate change. These also exert demand-side impacts (e.g. requirements for space heating, cooling, water consumption) and increased probability of extremes (e.g. heatwaves, droughts, floods, cold winters) (IPCC, 2013). It is crucial to take account of the stresses imposed on integrated energy systems to ensure system resilience during and after extreme events.