I have just been idly surfing and have landed at a discussion on whether there was a database of open databases. Of course, the answer is that there are many and they are called data hubs or registries.
I also learned that Google have a service I did not know about, the Google Data Explorer. Here's an example of per capita greenhouse gases for some countries whose name starts with 'N'. Look, New Zealand is at the top, mainly due to our emissions from pastoral agriculture.
The data is up to 2012 and is credited (in the footer of the page) to the World Resources Institute CAIT 2.0 climate data explorer. Then oddly, in the next line of the footer, is the annotation "copyright Google 2014". I guess I am surprised not to see a Creative Commons licence.
A little more exploring revealed that someone had asked the question what is the copyright if I want to use a graph on Wikimedia?. The question was asked in 2013 and has never been answered. My answer would be just get the data from CAIT 2.0 climate data explorer, make your own graph and upload to Wikimedia Commons where you of course choose a Creative Commons licence.
That reinforces this comment on the original database of databases discussion.
"Google Public Data Explorer is very limited in scope, rather than the comprehensive catalogue of the world's data that I suggested they might choose to do. GPDE has only 136 datasets, for which they done the manual work of putting into a database, so that they can offer visualizations. I can't see any activity on it since launch in 2010".
So I guess Google starts projects, but sometimes just doesn't maintain them.