Learn about cumulative effects

What are cumulative effects?

The term “cumulative effects” generally refers to the combined impacts of past, present, and reasonably anticipated future human activities and natural processes. For example, multiple effects resulting from past, existing, or future development, such as loss of habitat, increased hunting and predators, and stress from forest fires, may result in cumulative effects to wildlife, including species at risk.

Specific definitions vary across jurisdictions and organizations, but the term generally refers to effects that may be individually minor, but collectively significant. Effects can be adverse, for example, deteriorated water quality in a regional river, or positive, for example economic benefits to a local community.

In a world of increasing economic activity and changing natural processes, it is important to be able to assess and manage cumulative effects on the environment, socio-economic conditions and human health.

The following video developed by Environment and Climate Change Canada provides a brief introduction to cumulative effects, using water quality as an example.