Ecology is about looking at how organisms relate to their physical surroundings and to each other. Normally, we think of this in terms of animals and plants as an ecosystem. Human ecology has the same basic principles, but it’s focused on humans and how we fit into the environment around us and which we depend upon - both natural and that which we've created.

It’s a kind of system thinking, looking at how a complex system works by examining the connections and interactions of the different components that make up the system. Although people are part of an ecosystem, it can also be useful to think of it as how a human social system interacts with the ecosystem and natural environment - the diagram below, drawn from Gerry Marten’s Human Ecology - Basic Concepts for Sustainable Development, is a useful illustration. As a discipline, human ecology crosses over with a range of other areas of study and science - from hard sciences like biology, geology and geography to human sciences like sociology, history, economics, psychology and archaeology.

When it comes to environmentalism, applying this kind of systems thinking allows us to look at not just how human behaviour is impacting the natural world, but how it’s having an impact on their own lives. It can help identify the factors that drive particular behaviours which includes not just elements of the physical environment or physical effects but the ideas and thinking. Understanding thought processes is a key part of making a change that will actually work in practice, and that will last.

Taking a human ecology view of pollution is particularly useful. Everyone knows pollution is a problem, but finding solutions is complicated because pollution is a result of the way we have come to live our lives. Waste products are formed in every kind of ecosystem, but in most cases those ecosystems have evolved together over time so that waste products can be absorbed and used by other aspects of the ecosystem. To take a really simple example, plants use up carbon dioxide in the process of photosynthesis and produce oxygen as a waste product - which many animals, including humans, breathe.

Pollution is the result of waste humans have started creating which cannot be absorbed and reused by the environment we live in and depend on - our ecosystem. This is often because of the massive scale of the waste produced, because the chemical makeup of the waste can’t be broken down or reused, or very often a combination of the two.

Taking a big picture approach that considers the huge variety of physical and social factors behind pollution, as well as the effects it is having on our lives and the wider ecosystem, can help to identify solutions that in turn integrate with people’s lives.