Fitting puzzle pieces together is analogous to how we study the Earth. By considering Earth as an integrated system, with many interlocking parts, we are able to understand the larger picture of global change.
The biosphere includes all life on our planet. Scientists study how biological processes, like photosynthesis, affect other parts of the Earth system. Humans are only a small fraction of Earth's biosphere, but our actions have a large impact.
The geosphere includes the rocks and minerals on Earth – from the molten rock and heavy metals in the deep interior of the planet to the sand on beaches and peaks of mountains. Beyond these parts, the geosphere is about the processes responsible for the constant recycling of rocks on Earth.
Accounting for all the energy that enters and leaves the Earth system helps us understand how the planet maintains a habitable temperature. This accounting of energy is known as Earth’s radiation budget.
Earth's biomes change over long time periods as a result of natural cycles, but can change more abruptly due to human impacts. Earth's forest biomes in particular are changing, as a result of agriculture, outbreaks of tree-killing pests, and wildfires.
As Earth’s population increases, human impacts on all the parts of the Earth system also increase. What are these impacts to air, water, land, and life, and why do we refer to our present time as the Anthropocene?