The greenhouse effect is the trapping of gases in a planets lower atmosphere, causing the planet's temperature to increase over periods of time.
Global warming, or climate change, is usually referred to the human-reduced warming of the Earth.
The carbon cycle is the biogeochemical cycle where carbon is exchanged among the biosphere(the regions of the surface, atmosphere, and hydrosphere of the Earth), the pedosphere(Earth's soil mantle), geosphere(the almost spherical concentric regions of matter that make up the Earth's atmosphere), hydrosphere(the water on the Earths surface), and atmosphere(a layer of gas or gases that envelope a planet).
Humans impact this relationship by using fossil fuels daily. Fossil fuels put carbon dioxide into the atmosphere. Our use of limestone to make things such as concrete and our changing land use also impacts this relationship.