Continuing a series on Evidence Based Practise (EBP) below are examples from sea level research of the biases mentioned previously from an interview with Dr. Nils-Axel Mörner. From wikipedia:

Nils-Axel Mörner is the former head of the Paleogeophysics and Geodynamics department at Stockholm University, having retired in 2005. He was president of the INQUA Commission on Neotectonics (1981-1989) and president of the INQUA (International Union for Quaternary Research) Commission on Sea Level Changes and Coastal Evolution (1999-2003).[1] He headed the INTAS (International Association for the promotion of cooperation with scientists from the New Independent States of the former Soviet Union) Project on Geomagnetism and Climate (1997-2003). He is a critic of the IPCC and the notion that the global sea level is rising.

Firstly, he establishes his evidence-based approach to determining sea level rises:

So, we have this 1 mm per year up to 1930, by observation, and we have it by rotation recording. So we go with those two. They go up and down, but there’s no trend in it; it was up until 1930, and then down again. There’s no trend, absolutely no trend.

He then recounts an instance of sample bias or ‘cherry picking’:

Another way of looking at what is going on is the tide gauge. Tide gauging is very complicated, because it gives different answers for wherever you are in the world. But we have to rely on geology when we interpret it. So, for example, those people in the IPCC [Intergovernmental Panel on Climate Change], choose Hong Kong, which has six tide gauges, and they choose the record of one, which gives 2.3 mm per year rise of sea level. Every geologist knows that that is a subsiding area. It’s the compaction of sediment; it is the only record which you shouldn’t use. And if that figure is correct, then Holland would not be subsiding, it would be uplifting.

He then relates a violation of the ‘uncertainty principle‘ ensuring no uncertainty about the results of a study:

Then, in 2003, the same data set, which in their [IPCC's] publications, in their website, was a straight line, suddenly it changed, and showed a very strong line of uplift, 2.3 mm per year, the same as from the tide gauge. And that didn’t look so nice. It looked as though they had recorded something; but they hadn’t recorded anything. It was the original one which they had suddenly twisted up, because they entered a correction factor, which they took from the tide gauge. So it was not a measured thing, but a figure introduced from outside. I accused them of this at the Academy of Sciences in Moscow. I said you have introduced factors from outside; it’s not a measurement. It looks like it is measured from the satellite, but you don’t say what really happened. And they answered, that we had to do it, because otherwise we would not have gotten any trend!

He then invokes funding bias, where financial interests bias the interpretation of trial results.

Then we know that there was a Japanese pineapple industry which subtracted too much fresh water from the inland, and those islands have very little fresh water available from precipitation, rain. So, if you take out too much, you destroy the water magazine, and you bring sea water into the magazine, which is not nice. So they took out too much fresh water and in came salt water. And of course the local people were upset. But then it was much easier to say, “No, no! It’s the global sea level rising! It has nothing to do with our subtraction of fresh water.” So there you have it. This is a local industry which doesn’t pay.

Then we have accusations of fraud, deliberate falsification of evidence:

A famous tree in the Maldives shows no evidence of having been swept away by rising sea levels, as would be predicted by the global warming swindlers. A group of Australian global-warming advocates came along and pulled the tree down, destroy-ing the evidence that their “theory” was false.

Finally we have publication bias, the selective publication of the findings of trials with certain results:

Instead of doing this, they give an endless amount of money to the side which agrees with the IPCC. The European Community, which has gone far in this thing: If you want a grant for a research project in climatology, it is written into the document that there must be a focus on global warming. All the rest of us, we can never get a coin there, because we are not fulfilling the basic obligations. … but it is exceptionally hard to get these papers published also. The publishers compare it to IPCC’s modeling, and say, “Oh, this isn’t the IPCC.” Well, luckily it’s not! But you cannot say that.

This interview has examples of all the forms of research bias mentioned previously. I can’t vouch for the accuracy of these claims as I have not researched them myself. It is presented to show that the concerns with bias in global warming research are almost identical to the issues of concern in the clinical studies medicine. There is a view that these concerns gave rise, after a series of scandals such as the Thalidomide tragedy, to the EBP movement.

From the point of view good scientific practice, and the diminishing evidence of global warming, the IPCC is looking more like a 60’s drug company: an organization with a product to sell, involved in unscrupulous marketing of its product in the absence of evidence of both safety and efficacy.