How human actions trigger environmental issues

The third Big Question

The chapter asks: how do human actions trigger environmental issues? Its world tour answers with examples from almost every stop. Mountains, oceans, forests and deserts give us water, food, oxygen and a steady climate, but when people use them faster than nature can repair them, the balance breaks down.

Coral reefs in danger

Coral reefs feed and shelter about a quarter of all ocean species, which is why they are called the rainforests of the sea. Climate change, pollution and overfishing are changing the chemistry of the water around them. Stressed corals lose their colour, or bleach, and many die, leaving fish, crabs, turtles and sponges without a home. Even the Great Barrier Reef, a UNESCO World Heritage Site over 2,000 km long, faces these threats, so protecting it is urgent.

Forests and grasslands

The Amazon Rainforest, fed by rivers from the Andes, is called the Lungs of the Earth because its trees take in carbon dioxide and give out oxygen. About 400 indigenous communities live in it and help conserve it. Yet the countries of the region also need land for farms, roads and towns, and the forest is shrinking through deforestation and climate change. In Africa, farming, tree cutting and climate change threaten the savannah grasslands where elephants, lions and zebras live, and in the Andes only about a quarter of the original plants and animals remain.

Frozen ground, dry land and polluted water

Near the Arctic, the soil of the treeless tundra, the permafrost, stays frozen and locks away carbon dioxide and methane like a giant freezer. Global warming thaws it, the gases escape, and the planet warms further. On the Tibetan Plateau, melting snow is making lakes grow and new ones appear. In Chile’s Atacama Desert, cheap fast fashion has created huge dumps of discarded clothes, and North America’s Great Lakes are polluted by farm run-off and industrial waste.

Repairing the damage

Damage can be reversed when people understand how an ecosystem works. In Yellowstone National Park, in the Rocky Mountains, too many elk were eating the plants. In 1995 wolves were brought back; they hunted the elk, the plants returned, and the ecosystem’s balance was restored. Nature also helps itself: the Eurasian Steppes act as a carbon sink, storing carbon underground. Protecting such places, and the people who care for them, is part of the answer.

Why it is everyone’s problem

The Earth’s features are linked. Dust blown from the Sahara carries phosphorus that feeds the Amazon’s plants, and the southern Indian Ocean shapes India’s monsoon. In the same way, forests cut in one country or gases released from distant tundra change the climate for all. That is why the chapter says that studying world geography helps us manage the planet wisely. Small choices count too: using less, wasting less, and caring for local forests, rivers and lakes are ways in which every one of us can help keep the planet in balance. See the Chapter 1 notes, continents and oceans and the NCERT solutions, including Question 9 on environmental issues.