Ecosystem services are the various benefits (goods and services) that humans receive from natural systems such as estuaries, wetlands, and forests. These services are often undervalued and taken for granted. The international Millennium Ecosystem Assessment identified four categories of ecosystem services: provisioning services such as food and water; regulating services such as flood and disease control; cultural services such as spiritual and recreational benefits; and supporting services such as nutrient cycling that maintain the conditions for life on Earth.
Sea level rise and coastal change are threatening ecosystem services such as flood mitigation, storm surge protection, and water quality treatment. For example, coastal forests help reduce the inland impacts of flooding and major storm events, but as sea level rises and the forests retreat, the capacity of the forests to buffer storms will diminish. This may result in increased flood damage to infrastructure and capital investments. The potential negative impacts of sea level rise and coastal change on ecosystem services, and consequently coastal communities, makes it critical to begin planning for future changes now.

Ecosystem Services