Climate Change but no AGW
There is no evidence of anthropogenic global warming
This page is a comment by "Tallest Skil" to the Zero Hedge article here. Some images on this page are by Robert A. Rohde (reproduced under a Creative Commons license).
Yes, climate changes. But there is absolutely no evidence that humans are having any impact on the climate whatsoever. In order to establish an actual human impact in a statistically significant way, you must show a modern trend that deviates from a baseline of appropriate duration. Because geologic processes spanning millions of years are responsible for tremendous amounts of variation in global temperatures, an appropriate baseline must necessarily include millions of years of data to account for this variation. Not only are we not in a period of “record high temperatures” we are in one of the coldest periods in the past 65 million years.
There is absolutely no evidence that current temperatures are outside the trend of totally natural variation, and all attempts to make it appear that way are misleading you by truncating the data to a sample of statistically insignificant size. And then they apply their misleading, exponential curve-fits and smoothing effects for dramatic purposes.
The Earth had had ice caps for maybe about half of the time over the past 500 million years. The picture shows rapid periods of melting and re-glaciation over periods of a few thousand years. There is nothing abnormal about current melting rates.
The sea level has been rising at a very steady and predictable rate over the past 8-10,000 years since the emergence from the last major glacial period with no deviation at all from this trend even as humans began industrializing. When environmentalists show you graphs going back 50-100 years of rising sea level data, they omit the fact that this is both on-trend and completely expected.
We have no actual data that indicates that climate is in any way behaving abnormally, much less due to human impact. The only thing we have is a hypothesis that CO2 affects climate in a meaningful way, which is what climatologists attempt to model. But those models make terrible predictions.
If your hypothesis consistently churns out inaccurate predictions — no matter how many times you tweak the knobs and change little fudge-factors here and there — then your hypothesis is shit and must be discarded. Morons who believe in this garbage have no understanding of basic epistemology, let alone science — and that goes for the so-called “scientists” peddling this mystical bullshit.
CO2 is only hypothesized to have the impact on global climate that the alarmists claim. But this has failed to be demonstrated in two major (but related) ways. First, carbon dioxide levels are currently being measured at several hundred ppm higher than measured from ice core samples. Now, it must also be cautioned that you can’t necessarily compare these two sets of data because they represent two different methods of measurement, and have other potential biases. However, even assuming that it’s true that CO2 levels are much higher — and that they’re caused by human activity — current temperatures are not deviating from the normal historical trends in line with CO2.
A doubling of preindustrial CO2, absent any feedbacks, would result in a maximum forcing of +1.2 °C. Everyone agrees on this point because it’s a simple computation given the physical characteristics of CO2 which is well mixed in the atmosphere.
Actual warming, again absent feedbacks, would likely be much less due to bandwidth overlap between CO2 and H2O, something that we understand but find difficult to model (H2O levels vary dramatically day to day and even hour to hour with regional weather).
The General Circulation Models, and the IPCC, predict 2-8 °C of warming because AGW theory assumes a positive H2O feedback. They assume that if CO2 causes a little warming, the atmosphere will hold more water vapor which will lead to a lot of warming until a new equilibrium point is reached.
The warming predictions cover such a large range because everyone assumes a different average feedback rate. Again, modeling H2O in the atmosphere is extremely difficult because it varies so much with weather.
Every GCM based on this assumption has failed to model temperatures for the past 15 years. They are all trending too high. In the late 1990s, the modelers themselves stated that if they missed their predictions for more then a decade that would falsify AGW theory.
There is no data to suggest a positive H2O feedback either now or in Earth’s past. Indeed, we cannot model some periods in Earth’s history with an assumed positive H2O feedback. It would appear that Earth’s atmosphere is remarkably adept at dampening forcings from either direction and does not amplify them.
If there is no positive H2O feedback, we literally have nothing to worry about. The average climate change believer knows none of this. Politicians, citizens, activists, and surprisingly even a lot of scientists are literally ignorant of the theory and the math. In their mind, it’s simply “CO2 = bad” and “experts say we’re warming faster then ever.” The more you know.
Not only are current temperatures not outside the normal trend, we are in one of the coldest periods in the past 65 million years. Also, current temperatures (at the peak of the current 100ky cycle) are actually lower than past 100ky cycles, meaning that we are expected to either warm further just by way of natural variation or we are in an unusually cold peak period.
Second, climate models that use CO2 as a major driver for global temperatures are not producing accurate predictions for global temperatures. This is at least good initial evidence that the alarmist stance on the CO2/climate hypothesis is false. Notice that current temperatures are in no way deviating from normal trends. and that the two “scary red dots” are not observed data, but “predictions.” But, as we already know, the observed data is wildly lower than the predictions. These people are completely full of shit.
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