It will cover the impact of global warming on food supplies and on forest, grassland, desert, aquatic, and alpine ecosystems and their wildlife.
(It; will cover; the impact of global warming on food supplies and on forest, grassland, desert, aquatic, and alpine ecosystems and their wildlife)
It
will cover
the impact of global warming on food supplies and on forest, grassland, desert, aquatic, and alpine ecosystems and their wildlife