Define the term "ecosystem services" and provide two examples.

"Ecosystem services" is a term used in environmental science to describe the many and varied benefits that humans freely gain from the natural environment and from properly-functioning ecosystems. These services are split into four main categories: provisioning, such as the production of food and water; regulating, such as the control of climate and disease; supporting, such as nutrient cycles and crop pollination; and cultural, such as spiritual and recreational benefits.

Example 1: Pollination of crops by bees is an example of an ecosystem service. Bees naturally pollinate flowers in the course of their nectar collection activities, and this pollination is crucial for the production of many of the fruits and vegetables that humans consume.

Example 2: Forests regulating the climate is another example of an ecosystem service. Forests absorb carbon dioxide, a greenhouse gas, which helps to moderate the Earth's climate. They also have a cooling effect locally, as they release moisture into the air through transpiration.