At the national level, it is difficult for donors to meet the aid effectiveness principle of aligning their inputs with country priorities if a developing country has not yet established such priorities. At the institutional level, varying national circumstances or enabling environments can enhance or inhibit an intervention’s success (e.g. a regulatory environment’s influence on an intervention’s ability to mobilise private finance). Site-specific environmental factors can also influence the performance of an intervention (e.g. a wind turbine will generate varying amounts of electricity depending on the prevailing wind speed). Some climate interventions can give rise to immediate results (e.g. energy efficiency projects). However, some interventions will target results that can only be assessed after an extended period of time (e.g. constructing infrastructure that can withstand a 1-in-100-year flood). These different time horizons for the results of an intervention mean that effectiveness levels will vary depending on when results are assessed.