Statistics can be a valuable information resource for many of your environmental science projects. Here are some good sources for statistics:
Asking these questions will help you to determine whether the resources you find are credible and reliable.
Who created the page? Does the person or organization have the appropriate credentials?
Why was this site created? What is the purpose of the site? For example, is it sponsored by a company that has a financial interest in the topic?
When was the page created and/or last updated? How current is the information?
Does the author cite trustworthy sources? How does the author support their argument?