Adiabatic lapse rate is the temperature curve a parcel of air would follow if it were raised or lowered adiabatically (no heat added or subtracted) due to the change in ambient air pressure. This can be calculated from the ideal gas law and the hydrostatic equation and is 9.76ºK/kilometer in Earth's atmosphere (dry rate).
Climate Sensitivity is defined as the change in global mean surface temperature (in °C) from a doubling of the atmospheric CO2 concentration. Here's a table of estimates of climate sensitivity, 1896-2006.
Also see Carbon Dioxide.
Global Historical Climatological Network, run by NOAA, is one of three global climate networks.
Inverse Regression is a statistical technique used for calibration... [dah dah dah]. Wahl & Amman 2006 attempted to salvage the MBH "hockey stick" using this technique — SM criticizes Mannian inverse regression here. Substituting Red Noise for data gives the same result, generating "a statistical classic as one of the most remarkable examples of overfitting that I’ve encountered."
Latent Heat is the amount of energy in the form of heat released or absorbed by a substance during a change of phase (i.e. solid, liquid, or gas): for example, the heat released when water freezes, or the heat absorbed when water evaporates. See also Sensible Heat.
Overfitting is "fitting a statistical model that has too many parameters. An absurd and false model may fit perfectly if the model has enough complexity by comparison to the amount of data available. Overfitting is generally recognized to be a violation of Occam's Razor" (definition from Wikipedia).
Red Noise: noise with energy monotonically decreasing as the frequency increases; unlike white noise where the same energy is found at all frequencies. Red noise was used by M&M to demonstrate the fallacy of the MBH98 (et al.) PCA proxy manipulation. Also see Colors of Noise
Rossby waves , also known as planetary waves, are large-scale motions in the ocean or atmosphere whose restoring force is the variation in Coriolis effect with latitude. They are large-scale meanders of the jet stream.
Sensible Heat is simply potential energy in the form of heat. In the atmosphere, large-scale transport of heat from the tropics to the poles is affected by sensible heat in the form of warm air moving toward the poles. See also Latent Heat.
Teleconnection: a strong statistical relationship between weather in different parts of the globe. More specifically, "teleconnection pattern" refers to a recurring and persistent, large-scale pattern of pressure and circulation anomalies that spans vast geographical areas. Teleconnection patterns are also referred to as preferred modes of low-frequency variability. These patterns can exist from time periods of several weeks to years and thus can explain large portions of the variability. For example, there appears to be a teleconnection between the tropics and North America during El Niño. (definition from NOAA)