In climate modeling, this is a problem that results from beginning a model simulation at a point in time when the climate response to natural and anthropogenic forcing that happened before the start of the simulation is already in progress. An example would be specifying 1950 initial conditions for a simulation of the effects of anthropogenic CO2 increases when the CO2 increases although the CO2 increases started in the latter half of the 19th century. This results in a simulation that is missing at least 50 years of the time evolution of the modeled system’s response to increasing atmospheric CO2, which can be vital to the prediction of future states of a system with components that change on time scales greater than 50 years, e.g. the ocean.