Reason number one why there is debate on "climate change".
When asked to see the data and methodologies used by the UK's National Weather Service in order to verify the results, the answer was no, you might find something wrong with what we did.
When asked by Warwick Hughes for this data, Dr. Jones famously replied:
Even if WMO agrees, I will still not pass on the data. We have 25 or so years invested in the work. Why should I make the data available to you, when your aim is to try and find something wrong with it.
When one side refuses to allow independent testing of scientific results, it ceases to be science.