How much of this warming is real? How much was created back in the office?

Andrew Bolt, Herald Sun (Australia)
How much can we rely on data adjustments by people convinced the evidence should show a warming?

THE Bureau of Meteorology has been accused of manipulating historic temperature records to fit a predetermined view of global warming.
Researcher Jennifer Marohasy ... has analysed the raw data from dozens of locations across Australia and matched it against the new data used by BOM showing that temperatures were progressively warming.
In many cases, Dr Marohasy said, temperature trends had changed from slight cooling to dramatic warming over 100 years.
BOM has rejected Dr Marohasy’s claims and said the agency had used world’s best practice and a peer reviewed process to modify the physical temperature records that had been recorded at weather stations across the country.
It said data from a selection of weather stations underwent a process known as “homogenisation” to correct for anomalies.

Same accusation in the US:


US measured temperature data (blue below) shows that we have been cooling for nearly a century. But the temperatures reported by NCDC (red below) show the opposite, that the US is warming…