Editing Climate variability and change (section)

=== Analysis and uncertainties ===
One difficulty in detecting climate cycles is that the Earth's climate has been changing in non-cyclic ways over most paleoclimatological timescales. Currently we are in a period of [[Human impact on the environment|anthropogenic]] [[global warming]]. In a larger timeframe, the Earth is [[Holocene glacial retreat|emerging]] from the latest ice age, cooling from the [[Holocene climatic optimum]] and warming from the "[[Little Ice Age]]", which means that climate has been constantly changing over the last 15,000 years or so. During warm periods, temperature fluctuations are often of a lesser amplitude. The [[Pleistocene]] period, dominated by repeated [[glaciation]]s, developed out of more stable conditions in the [[Miocene]] and [[Pliocene climate]]. Holocene climate has been relatively stable. All of these changes complicate the task of looking for cyclical behavior in the climate.

[[Positive feedback]], [[negative feedback]], and [[ecological inertia]] from the land-ocean-atmosphere system often attenuate or reverse smaller effects, whether from orbital forcings, solar variations or changes in concentrations of greenhouse gases. Certain feedbacks involving processes such as clouds are also uncertain; for [[contrail]]s, natural [[Cirrus cloud|cirrus]] clouds, oceanic [[dimethyl sulfide]] and a land-based equivalent, competing theories exist concerning effects on climatic temperatures, for example contrasting the [[Iris hypothesis]] and [[CLAW hypothesis]].