Anticipating the consequences of climate change is arguably the most pressing challenge at the interface of science and society. Forecasting the ecological futures of Earth’s ecosystems requires understanding not only the long-term consequences of changes in average climate, but also the impacts of increasing variability in climate at seasonal and inter-annual time scales. Prior empirical work, particularly existing climate change experiments, has largely emphasized mean climate trends, with some attention to extreme events. Yet, theory predicts that temporal variance in climate can have powerful ecological impacts. Effects of variance can arise from nonlinearities in ecological responses to climate variables and stochasticity in climate events. Empirical resolution of the effects of variance in climate has lagged behind theory because these effects often play out over timescales that exceed standard funding cycles, making this a critical scientific frontier.