"so if the 3 warmest years since the 1800s are in the last decade, that sort of supports the global warming thing right? "
It supports global warming from the 1800's (the end of the little ice age or thereabouts), it doesn't support anthropogenic global warming. Presumably something stopped the little ice age and I doubt there was enough CO2 released in the 18th & 19th centuries to be the cause of that temperature rise.
Up until the late 90's there was a correlation between increased CO2, due to mankind's industry, and temperature, but that correlation between the two appears to have broken down in the last 15 years.
My conclusion is that no one knows yet but that further study is warranted before governments start taxing the crap out of us and telling us how to live.