FYI, I found the website that says they are similar
Environment and Humanity: The Race to Save the Planet - Credit by Examination - DANTES
Here is an excerpt from this site.
Earn three college semester hours credit in "Environment and Humanity: the Race to Save the Planet" by passing DANTES examination SF-511 or SG-511 with a recommended scaled score of 46 ( out of 95 ) using this study guide:
Begin your study by downloading the official Fact Sheet for this exam. (If Thompson Prometric has moved these (again) try here.
It is a little-known fact that this exam is nearly the same as the AP Environmental Science exam, and you can use the same study guides to prepare for it.
Assess your current readiness for the exam by reviewing the Content section and answering the sample questions.
Obtain materials to improve your skills in areas where you need additional study from among the following: