Which isn't necessarily a bad thing.
What people are seeing through the personal emails that were sent back and forth between these scientists is something that most people haven't seen before, that scientists can be nasty, thuggish and may even 'massage' data in order to get the answers they want or the answers that will make headlines.
The scientists dumped the raw data and only maintained the 'value-added' data. They boasted that they will ignore certain inconvenient papers that passed peer-review. They openly admit that some of their data sets are 'inferior' and that the scientists responsible are 'doing something very odd'. There are suspicions that they have manipulated data to show results inconsistent with the actual records available.
From the last link, an email conversation between two scientists:
[Karlen] In attempts to reconstruct the temperature I find an increase from the early 1900s to ca 1935, a trend down until the mid 1970s and so another increase to about the same temperature level as in the late 1930s.
A distinct warming to a temperature about 0.5 deg C above the level 1940 is reported in the IPCC diagrams. I have been searching for this recent increase, which is very important for the discussion about a possible human influence on climate, but I have basically failed to find an increase above the late 1930s.
[Trenberth] This region, as I am sure you know, suffers from missing data and large gaps spatially. How one covered both can greatly influence the outcome.
Even that last comment from Trenberth doesn't surprise me nearly as much as perhaps it should. What he seems to be saying is that how you massage the data may bring out different results because the quality of the data available is so poor.
Are you really surprised?
This is just a small window into the world in which many scientists work. The drive for funding leads some into exaggerating progress and applicability and making bold predictions that they themselves likely do not believe. Ideological viewpoints are reflected in how sensitive data is manipulated and reported to the public. Some scientific results reported will be flat out wrong even though the scientists themselves may sincerely believe what they report. Mere statistical noise can be thoroughly examined and expanded into an entire thesis topic, never to be seen again.
Studies regarding radiation hormesis, cold fusion, health 'benefits' of alcohol, chocolate and numerous other controversial topics often will contradict each other despite many passing some form of peer-review. Even many non-controversial topics will be fraught with contradictions between studies.
Historical scientific personalities often had interesting personal lives that would probably shock people today. I'm thinking of Milikan and Harvey Fletcher's oil drop experiment and Einstein and his affair with his first cousin in particular.
None of this devalues the actual work being done by these or other scientists everyday nor the theories they espouse, but simply should remind us to take everything we read or hear with a grain of salt. Even if the person has a Ph.D from a prestigious university.