And the natural variation includes gradual warming after the little ice age.
Other forms of natural variation are the climate modes. Some of the modes include:
North Atlantic Oscillation (NAO)Atlantic Multidecadal Oscillation (AMO)Pacific North American pattern (PNA)Pacific Decadal Oscillation (PDO)El Niño-Southern Oscillation (ENSO)Northern Annular Mode (NAM; previously called the Arctic Oscillation, AO)Southern Annular Mode (SAM; previously called the Antarctic Oscillation, AAO). There are many more modes. They have different time scales. They are dynamic and superimposed with the daily chaos of the hydrological cycle.
Water is the dominant greenhouse gas, the powerhouse of insulation and energy absorption/release. Clouds provide the most uncertainty, as stated by the IPCC. Clouds, as the below article states, have "an extremely small-scale, short-lived dynamical process...a substantial effect on the planet's global and long-term energy budget." Something like 20% of solar radiation is absorbed by water vapour. This is a +ve and -ve feedback system whose effects dwarf the effect of the extra ~120ppm CO2 we've reintroduced to the system since the industrial revolution.
