Subject encyclopedias, handbooks and overviews are scholarly, tertiary works written by experts on a variety of topics and are designed to be consulted early on in a research project. The entries are written by scholars and typically provide an overview of both the topic and the ways that scholars have interpreted this topic. These resources can help you with:
In Collins Library, the print reference collection is located on the first floor, and most of the online reference collection is available in one of the database collections listed on the right. Use Primo to identify subject encyclopedias in either format; or ask a librarian for recommendations.
The Cambridge Introduction to Literature and the Environment by 
The Oxford Handbook of Ecocriticism by 
The Cambridge Companion to Environmental Humanities by 
Environmental Literature: an encyclopedia of works, authors, and themes by 
Encyclopedia of Literature and Science by 
Encyclopedia of American Cultural and Intellectual History by 
American Environmental Leaders: from colonial times to the present by 
Encyclopedia of American Environmental History by 
Encyclopedia of Environmental Ethics and Philosophy by 
Encyclopedia of Environment and Society by 
Encyclopedia of Environmental Change by 
Encyclopedia of Global Warming and Climate Change by 
Encyclopedia of Environmental Studies by Not sure where to look? Each of these online collections will introduce you to a wealth of encyclopedias, dictionaries, and other tertiary sources.