Wood Romances

GMST in Various Datasets Since 2013 or so, it's been common to refer to global warming over the last 100 years or so as "real," "man-made" and "dangerous."[1]. To my knowledge, these terms were first used in political discussion, but I believe they can be useful categories for discussing whether it's happening (real), whether it's something we can correct (man-made) and whether it's a problem that needs correcting (dangerous). These three categories of claims do a good job of summarizing how a case can be built that we have a problem that we both can fix and need to fix. These categories are valuable because 1) we can only potentially have a climate warming problem if global warming is real. If it's 1) real and it's 2) man-made, then we have the capacity to fix it by changing what we're doing. If, however, it's mostly natural, then potentially there's nothing we could do to fix the problem, and that's really bad news...

Little Big Econ State Forest (just because it's pretty) Any given climate forcing affects the Earth's Energy Imbalance (EEI) - that is, it affects the amount of energy entering the climate system vs energy escaping into space. When a forcing occurs, such as from an increase in CO2, the imbalance is created and surface temperature increases until EEI returns to equilibrium (that is, EEI = 0). But how long does this take? That is, what is the lag between a climate forcing and the new equilibrium temperature? It turns out, this depends on sensitivity and the rate of temperature increase, but it is possible estimate the time to achieve this equilibrium with a forcing. But this is going to be rather math-intensive. Apologies in advance! We can begin with a simple energy balance equation: (1) ΔF = ΔT/ λ  + EEI, where λ is sensitivity (ECS/F2x) ECS is Equilibrium Climate Sensitivity F2x is the forcing for doubling CO2 EEI is the Earth's Energy Imbalance ΔF is the change in radiati...

Comparison of Loehle 2008, Pages 2K and HadCRUT5 In 2007, Loehle published a multiproxy study[1] estimating global temperature over the last 2000 years. It's distinctive feature was that it removed all tree ring proxies, leaving only 18 proxies to estimate global temperatures. According to the abstract the paper shows a warm MWP compared to today. "The mean series shows the Medieval Warm Period (MWP) and Little Ice Age (LIA) quite clearly, with the MWP being approximately 0.3°C warmer than 20th century values at these eighteen sites." Loehle 2007 Temperature Reconstruction Admittedly this reconstruction looks very different from the "hockey stick" reconstructions from Mann and other authors. However, Loehle's reconstruction contained several errors in the way the dates were handled, and once discovered, a revised version of this paper was published in 2008.[2] "Several errors in data handling in that report have come to light, leading to the need for th...

Central Greenland Temperature Reconstruction In 2000, R. B. Alley published the results of a proxy analysis of a single ice core in Central Greenland as part of the GISP2 project.[1] The resulting time series reconstructs local temperature fluctuations over the last 50,000 years. The graph above includes only the last 15,000 years; you may see versions of this graph showing the last 10,000 or 12,000 years. The proxy reconstructs temperatures at the Greenland Summit (the GISP2 project) using the ratio of two different oxygen isotopes: 18O and the more abundant 16O. Lower the 18O/16O ratio indicates lowers temperatures, since as temperatures decrease, a more 18O precipitates out at lower latitudes, making the 18O/16O ratio smaller over Greenland. Alley's time series ends 95 years BP, or 95 years before 1950, so the last data point in this analysis is 1855. The IPCC and other organizations are interested in modern warming frequently consider modern warming as measured against the 1850...