There are a vast number of resources - those available through the UCSD library and those that are free - that may be helpful in your research. I've listed below some of the best places to get started, but you may have to go beyond these sources. If so, I recommend reviewing the library's Data and Statistics guide, which links to a large number of databases and websites.
You can also often find freely available statistics/data on the web. One good way to focus your search to find this kind of information is to add (data OR statistics) - including the parentheses - to a Google keyword search, such as ("global warming" OR "climate change") (data OR statistics)