I graphed some data from the Earth Policy Institute. This chart is from data in the table Global Average Temperature 1880-2008. I think the data shows a long term trend of increasing temperatures across the globe:
However, when you hear someone say there’s been a decline over the past 10 years, they are being truthful but misleading. Here is the data they are looking at (1998-2008) which certainly looks like a decline:
This graph uses the same data but 1998 happens to be one of the warmest years on record. Those 10 years are the last two peaks in the 130 year graph.