Someone using the web moniker of “Manhattan Contrarian” has written a series of over 20 blog posts purporting to expose global warming and its associated climate changes as the “Greatest Scientific Fraud of All Time.” Such grandiose claims immediately invite skepticism, of course, but let’s look closely at this person’s claims, blog post by blog post, starting with the first, which was published in July 2013.
The main claim in his first post is that the global temperature data has been fraudulently adjusted by U. S. government agencies in order to exaggerate the rate of global warming. Of course, common sense would tell you that his claim is far-fetched. The fraudulent behavior he is accusing scientists of would have to be a coordinated effort not just of US scientists, but of scientists from countries all over the world. It would have to involve thousands of individuals who certainly are not in close communication with each other. It would have to continue over years as personnel changed at the various government agencies. It would have to have been done so cleverly that even when someone stole a bunch of emails, there would be no smoking guns revealed.
The blogger relies on two “authorities,” Joe D’Aleo and Steven Goddard. He could not have picked weaker ones. Goddard is so bad he doesn’t even get to post anymore at the climate denier site, Watt’s Up With That. D’Aleo is a meteorologist, but not too good at climate science. Goddard supposedly has found dozens of cases where temperatures were adjusted downwards for earlier years supposedly “to make the present appear warmer by comparison.” D’Aleo did a comparison of the US temperatures anomalies in the twentieth century as they were calculated in 1999 and then in 2011. He notes that 1934’s temperature was adjusted downward yet 1998 was adjusted upwards, thus making 1998 the warmest year at that point.
The problems with these two sources is that they are not giving us the full picture, nor are they considering the possibility that there are legitimate reasons to adjust temperatures. Though Goddard did find “dozens” of examples of downward adjustments for earlier years, did he even look for upward adjustments in those years? Did he consider why they were adjusted? Similarly, with D’Aleo, we can note that even though 1934 was adjusted downward in the charts he shows, other earlier years show little change. Also, the years since 1998 have been significantly warmer, thus showing that the trend is clearly upward.
There are good reasons for adjustments. See for example this article, where the writer takes on some people making similar claims as D’Aleo and Goddard: https://blog.hotwhopper.com/2015/02/paul-homewood-and-christopher-booker.html. Sometimes there are changes in the time of day the temperatures were taken at a given station, sometimes the station was moved, sometimes conditions changed near a given station, and sometimes the station provides temperatures significantly out of keeping with the temperatures at nearby stations. All of these mean that the raw data are not as accurate as they could be, and so adjustments are in order.
But just in case you think we should just go with the raw data anyway, consider that scientists have tried that approach as well. When then compare the trends using raw data and using adjusted data, the results are only slightly different. Just look at the results of the Berkeley Earth Surface Temperature project. If thousands of scientists were going to engage in a vast, sophisticated conspiracy to publish fraudulent data, they would want to make far greater adjustments. Instead, they want to be as accurate, as close to the real temperature as they can get, and so they make adjustments.
The Manhattan Contrarian pretends that if “there were a reasonable explanation [for the adjustments], the government should have come out with it a long time ago.” But government and non-government scientists have provided reasons. The Manhattan Contrarian is too lazy to look them up or too biased to understand them. And thus it is easy for him to blithely conclude that “the case for fraud has been proved.” In reality, the only thing he has proved is his own gullibility.