Here is a quick primer on reproducibility.
It is fundamental that scientific results have to be reproducible in order to be accepted as valid. You have to describe exactly what you did, in sufficient detail for somebody else to be able to reproduce what you say you did. If they can't, and you can't explain where they went wrong, then the result should be written off as erroneous or even fraudulent
Publications have a data availability policy. This varies from publication to publication, but it is a common condition of acceptance that authors agree to honour any reasonable request by other researchers for materials, methods, or data necessary to verify the conclusion of the article. This policy is in support of experimental replication. Because without data availability you don't have science, you have assertion.
For an example of a DAP: Nature's data availability policy can be viewed here
And I quote:
An inherent principle of publication is that others should be able to replicate and build upon the authors' published claims. Therefore, a condition of publication in a Nature journal is that authors are required to make materials, data and associated protocols promptly available to readers without preconditions.
Some publications, notably Philosophical Transactions of the Royal Society B (the Biology journal of the Royal Society) go further than this, requiring their authors to place the supporting data in the public domain prior to submission. This is an example of a ‘strong’ DAP.
Are these DAPs enforced? In the case of the journals Science or Nature, I get the impression that they’re not well enforced – at least not with respect to AGW articles. In the case of Philosophical Transactions, they are rigorously enforced. In passing, the PT’s rigorous DAP is the reason why we now know that Briffa’s hockey stick graph was based on modern data taken from a mere dozen trees while masses of other tree-ring data was ignored. This is the so-called "Yamal Implosion".
Seriously, if you have an ‘extremely well-regarded peer-reviewed journal’ that doesn’t both require and enforce rigorous data-availability on its contributing authors then it might as well be a children's comic.
These CRU emails are apparently genuine: which means that some or all of the writers were holding back or even destroying experimental data. And - apparently - in defiance of an FOI. That’s not science, but it might be jail-time.
How in Hell is meteorological data "restricted". This claim by itself should raise all kinds of red flags that there is something devious about the whole climate science establishment.