Human Footprint

Human Footprint 🌍

There are more than **8 billion** of us, each using resources and making waste. That footprint is reshaping ecosystems everywhere. This module maps our impact — pollution, land use, deforestation and warming — and, crucially, what can be done to protect **biodiversity**.

What biodiversity is 🐝

**Biodiversity** is the **variety of all the different species** of organisms in an ecosystem (or on Earth). A **high** biodiversity makes an ecosystem **more stable** and **sustainable**, because species are **less dependent** on any single other species for food, shelter or maintaining their environment. Our own future depends on maintaining biodiversity — yet many human activities reduce it.

Why it matters

Why does a high level of biodiversity help an ecosystem stay stable?

• Species are less dependent on any single other species to survive
• There are fewer organisms to feed
• It removes all competition between species
• It makes the climate warmer

More people, more waste 🏭

As the population grows and living standards rise, we use more resources and produce more waste. Without proper handling, that causes **pollution** in three places: • **Water** — from sewage, fertiliser run-off and toxic chemicals. • **Air** — from smoke and acidic gases. • **Land** — from landfill and from toxic chemicals. Pollution kills plants and animals, which **reduces biodiversity**.

Where does it pollute?

Running out of room 🏗️

Humans also reduce the land available for other plants and animals. We take it over for: • **building** (houses, factories, roads) • **quarrying** (digging out rock and minerals) • **farming** • **dumping waste** Destroying **peat bogs** for compost and farmland is especially damaging — it wrecks a rare habitat **and** releases stored carbon dioxide.

Cutting down forests 🌳

Large-scale **deforestation** in tropical areas clears trees to: • make land for **cattle** and **rice** fields • grow crops for **biofuels** The consequences are serious: **loss of habitat and biodiversity**; **less carbon dioxide absorbed** by trees; and **carbon dioxide released** when trees are burned or decompose.

What deforestation does

Pick the TWO consequences of large-scale deforestation.

• Loss of habitat and biodiversity
• Release of carbon dioxide, a greenhouse gas
• More carbon dioxide absorbed from the air
• Cooler global temperatures

A warming world 🌡️

Rising levels of **greenhouse gases** — mainly **carbon dioxide** and **methane** — are causing **global warming**. For living things this means: • **loss of habitat** (e.g. melting ice, flooding of low-lying land) • changes to the **distribution** of species, as areas become newly suitable or unsuitable • changes to **migration** patterns, and threats to **food production** — all reducing biodiversity.

Follow the warming

An interactive activity.

Protecting the web 🌱

It isn't all bad news — there are real ways to **maintain biodiversity**: • **Breeding programmes** for endangered species. • **Protecting and regenerating** rare habitats. • Reintroducing **field margins and hedgerows** where farmers grow only one crop. • **Reducing deforestation** and **carbon emissions** by governments and businesses. • **Recycling** resources rather than dumping waste in landfill.

Give nature a hand

A farmer grows a single crop across a huge field. Which action would most directly help local biodiversity?

• Reintroduce hedgerows and field margins around the crop
• Plant even more of the same single crop
• Pave the edges of the field
• Drain a nearby peat bog for more land

In the exam 🎓

Footprint mapped. Grade-9 habits for human impact: • Argue **biodiversity's** importance: high biodiversity → more **stable, sustainable** ecosystems. • Link each activity to a **specific** consequence — deforestation → habitat loss **and** CO2 release; peat destruction → stored CO2 released. • Global warming changes species **distribution** and **migration**, not just temperature — and name real fixes (breeding programmes, habitats, hedgerows, recycling).