User:Beccam51/sandbox

As explained in the Wiki training modules, a good goal to set for any article is to include a citation of sources in nearly every paragraph. However, there are a significant number of claims that lack a citation, and entire paragraphs go without. I think a citation should be added after the first paragraphs definition, in the Proxies subsection, and the tree rings subsection, as these sections all lack citations. On a positive note, the citations that are part of this article are mostly well-cited academic journal articles or textbooks written by scientists respected in their fields. Many links are provided and working well.