Much of the inter-annual to decadal scale variability in surface air temperature (SAT) anomaly patterns and related ecosystem effects in the Arctic and elsewhere can be attributed to the superposition of leading modes of variability in the atmospheric circulation. (tamino.wordpress.com)
On this latter scale teleconnections manifest as a response of middle - latitude weather to the dominant modes of variability of the tropics (the Madden - Julian Oscillation and the Boreal Summer Intra-seasonal Oscillations, which similar to El Niño and La Niña characterize variations of climate but on shorter time scales). (eos.org)
Global mean temperature at the Earth's surface responds both to externally imposed forcings, such as those arising from anthropogenic greenhouse gases, as well as to natural modes of variability internal to the climate system. (pnas.org)