The Meaning and Utility of Averages as it Applies to Climate

by Clyde Spencer, April 23, 2017


By convention, climate is usually defined as the average of meteorological parameters over a period of 30 years. How can we use the available temperature data, intended for weather monitoring and forecasting, to characterize climate? The approach currently used is to calculate the arithmetic mean for an arbitrary base period, and subtract modern temperatures (either individual temperatures or averages) to determine what is called an anomaly. However, just what does it mean to collect all the temperature data and calculate the mean?

USGS Estimates 304 Trillion Cubic Feet of Natural Gas in the Bossier and Haynesville Formations of the U.S. Gulf Coast

USGS, April 13, 2017


The Bossier and Haynesville Formations of the onshore and State waters portion of the U.S. Gulf Coast contain estimated means of 4.0 billion barrels of oil, 304.4 trillion cubic feet of natural gas, and 1.9 billion barrels of natural gas liquids, according to updated assessments by the U.S. Geological Survey. These estimates, the largest continuous natural gas assessment USGS has yet conducted, include petroleum in both conventional and continuous accumulations, and consist of undiscovered, technically recoverable resources.

How inconstant are climate feedbacks – and does it matter?

by Nic Lewis, April 18, 2017


There is as yet no observational evidence that climate sensitivity increases with time in the real climate system – although this cannot be ruled out – nor is it fully understood why it increases in most AOGCMs. In any event, even if real-world climate sensitivity does increase with time, in the longer run other factors that are not reflected in ECS, such as melting ice sheets, are probably more important. Therefore, while time-varying climate sensitivity is of considerable interest from a theoretical point of view, for practical purposes its influence is likely to be very modest.