On the left, bloggers like Illusory Tenant are redefining the term "denialist." There is, they say, nothing to see here and "
wing nuts" who say other things are so stupid - not at all like us smart people.
No, actually using a "trick" to "hide the decline" is a big deal. The problem is not that no one could figure out what they were doing (although it apparently took Michael Mann a while to figure it out). Steven McIntyre was certainly aware of it and unsuccessfully tried to persuade the IPCC not to do it.
The problem is that it reflects a willingness to assume away inconvenient facts and then to construct graphs for broader public consumption that "hide" those facts and that are, taken by themselves, fundamentally dishonest. Combining proxy data with actual measurements is a "trick" in the bad sense of the word. It acts as if apples and oranges are the same thing.
More fundamentally, it reflects a bias toward a particular conclusion. Apparently tree ring density was a good proxy for recorded temperatures for the first 60 to 80 years for which actual temperature measurements are available. After at least 1960, it is not. When attempting to make a claim about temperature trends over centuries, this is a problem. How can we know whether the period before 1880 is like the period from 1880 to 1960 or like that since 1960? How can we know that the relationship between tree rings and temperature is constant over those hundreds of years?
If we don't know that, then how can we know that the observed rise in temperatures over the past one hundred years or so is not simply part of normal climate fluctuations? Good science does not respond to the problem by calling it a "travesty" and acting as if it does not exist. Good science, as McIntryre points out, requires that you acknowledge the problem - including in documents that you want policymakers to rely on like the IPCC reports - and deal with it. That insiders knew about the issue does not justify deceptive representations of the data to the larger community.
The discarded data is a problem. It's not that there aren't other data sets and the raw data used by CRU might be reconstructed, but it was an important, widely used and much adjusted data sets. Now the adjustments can not be readily examined. Given what the e-mails tell us about problems with the data set and the raging partisanship revealed by the e-mails, this is a rather large problem.
One of the best summaries of this has been written by Steven Hayward in the Weekly Standard. Here's his conclusion:
Climate change is a genuine phenomenon, and there is a nontrivial risk of major consequences in the future. Yet the hysteria of the global warming campaigners and their monomaniacal advocacy of absurdly expensive curbs on fossil fuel use have led to a political dead end that will become more apparent with the imminent collapse of the Kyoto-Copenhagen process. I have long expected that 20 or so years from now we will look back on the turn-of-the-millennium climate hysteria in the same way we look back now on the population bomb hysteria of the late 1960s and early 1970s--as a phenomenon whose magnitude and effects were vastly overestimated, and whose proposed solutions were wrongheaded and often genuinely evil (such as the forced sterilizations of thousands of Indian men in the 1970s, much of it funded by the Ford Foundation). Today the climate campaigners want to forcibly sterilize the world's energy supply, and until recently they looked to be within an ace of doing so. But even before Climategate, the campaign was beginning to resemble a Broadway musical that had run too long, with sagging box office and declining enthusiasm from a dwindling audience. Someone needs to break the bad news to the players that it's closing time for the climate horror show.