Ecology and society

Look around your classroom: uniforms, desks, bags, fans. Every object comes, in the end, from nature. A wooden chair travels from a tree through loggers, carpenters, transporters and traders, using electricity, diesel and telecommunications along the way, and each of these draws on nature too. Mapping such resource flows shows how complex our relationship with the environment is.

Ecology is the web of physical and biological systems and processes of which humans are one element: mountains, rivers, plains, oceans, plants and animals, shaped by geography and hydrology (water flows). A desert's plants and animals, for example, are adapted to scarce rain, sandy soil and extreme heat, and ecology limits how people can live there too.

• Over time, human action has modified ecology. Something that looks 'natural', such as aridity or a river's tendency to flood, is often produced by people: deforestation in a river's upper catchment can make it more flood-prone; global warming is human-made climate change. Often it is hard to separate natural and human causes.
• Some 'natural' landscapes are shaped by people. The book's examples include Delhi's Ridge forest and the chaurs (wide grassy meadows) of Corbett National Park in Uttarakhand, which were once agricultural fields: villages were relocated to create what now looks like pristine wilderness.
• Other environments are clearly human-made: a farm with its terraces, crops, livestock, fertilisers and pesticides; a city of concrete, brick, glass and tar.

Social environments emerge from the interaction of biophysical ecology and human action. It is a two-way process:

• Nature shapes society. The fertile soil of the Indo-Gangetic floodplain allows intensive farming, dense settlements and surpluses that support non-farm activities, complex hierarchies and states. The Rajasthan desert can support mainly pastoralists, who move with their herds in search of fodder.
• Society shapes nature. The social organisation of capitalism has reshaped nature worldwide. The private car is one capitalist commodity that has transformed lives and landscapes, bringing air pollution and congestion in cities, conflicts and wars over oil, and global warming.
• The Industrial Revolution's footprint was global: plantations across southern North America and the Caribbean grew cotton for Lancashire's mills, worked by enslaved West Africans; West Africa's farms fell into fallow as people were taken away; coal smoke fouled British air; displaced rural workers lived in wretched city conditions.
• Example (new): a hill town that builds hotels on every slope for tourists may face landslides and water shortages a few years later: society reshaping nature, and nature answering back.