Browse by Dewey numbers:
363.7 Environmental Topics (pollution, acid rain)
550s Earth Sciences (water, meterology)
580s Plants (Botany)
635s Horticulture (Gardening)
The 363.7 Reference Section is on the tall bookshelf behind the circulation desk in the corner.
The 500s - 600s Reference Section is on the tall reference shelf opposite the book drop.