The Climate Research Unit of the University of East Anglia and the Hadley Centre of the UK Met Office have developed very comprehensive global climate data sets that start from the year 1850. These are regularly updated and are available online at

Using the HadCRUT3 annual global mean temperature anomaly (w.r.t. 1961-1990 average) data, I have plotted a time series for the recent years 1996-2011 and it is shown below:

The graph speaks for itself!