You are here
Our fuels, forests cleared and fertilisers overused are straining the very cycles that keep the Earth balanced — but local action and global cooperation can still turn things around.
- Excess atmospheric CO₂ increases ocean absorption, making sea water more acidic and threatening plankton and coral reefs; warmer water also absorbs CO₂ less well.
- Burning fossil fuels and deforestation saturate natural carbon sinks (forests and oceans), and the excess CO₂ intensifies greenhouse warming, disrupting the carbon cycle.
- India still generates much electricity from fossil fuels but is rapidly expanding solar and renewable energy.
- Overuse of fertilisers adds excess nitrogen (nitrates) to rivers and lakes, causing algal blooms that deplete oxygen and kill fish — a process called eutrophication (Fig. 13.17).
- Deforestation reduces photosynthesis and transpiration (lowering local rainfall), alters surface albedo and increases soil erosion.
- Over time habitats are destroyed, leading to a decline in biodiversity as species lose their homes.
NCERT Question 8 — What are the impacts of
… photosynthesis stopped, what would happen on the Earth? Oxygen would stop being replenished, plants (the base of food chains) would die, CO₂ would build up, and almost all life — including us — would eventually perish.
- Vehicular emissions react with sunlight to form ground level smog .
- This also leads to the formation of ground level ozone , which is harmful for health — remember that ozone in the stratosphere blocks UV radiation and is protective of life.
- These pollutants make city air unhealthy .
- A combination of local actions and global cooperation can restore the Earth’s systems — the Montreal Protocol has begun healing the ozone layer.
- However, the Kyoto Protocol and the Paris Agreement , in which countries were supposed to reduce their CO 2 emissions, have been less successful .
- Conserving energy, switching to renewable sources (solar, wind), planting trees, saving water and sustainable farming all help restore balance.
- Individuals can contribute by reducing, reusing and recycling and by saving water, food and energy.
Mission LiFE (Lifestyle for Environment), an India-led global initiative launched at the 2021 UN Climate Change Conference, encourages mindful, eco-friendly lifestyles. Building on India’s traditional view of the Earth as an interconnected system, it highlights how simple habits — saving energy and conserving resources — can build a sustainable future.
6. Human activities like burning fossil fuels, deforestation and overuse of fertilisers increase greenhouse gases. As an individual you can reduce emissions by saving energy, using public transport, planting trees and reducing, reusing and recycling.
-
What is eutrophication?
Show answer
The widespread growth of algae (algal blooms) caused when excess nitrogen from fertilisers reaches rivers and lakes. The blooms deplete oxygen and kill fish. -
Name two human activities that raise atmospheric CO 2 .
Show answer
Burning fossil fuels and deforestation. Together they have raised atmospheric CO 2 by about 35% since 1960 (315 ppm to 420 ppm). -
Which international agreement helped the ozone layer recover?
Show answer
The Montreal Protocol, which reduced the use of CFCs. The ozone layer is now slowly recovering.
- Eutrophication — the widespread growth of algae (algal blooms) caused by excess nitrogen from fertilisers reaching water bodies; the blooms deplete oxygen and kill fish.
- Carbon sink — a natural reservoir such as a forest or an ocean that absorbs more carbon than it releases.
- Ground level smog — the haze formed when vehicular emissions react with sunlight near the ground.
- Ground level ozone — ozone formed near the ground from these pollutants; unlike stratospheric ozone, it is harmful to health.
- Global warming — the rise in the Earth’s average temperature caused by excess greenhouse gases.
- Deforestation — the large-scale clearing of forests, which reduces photosynthesis and transpiration, alters albedo and increases soil erosion.
- Renewable energy — energy from sources like the Sun and wind that are not depleted by use.
- Montreal Protocol — the global agreement that reduced the use of CFCs and is helping the ozone layer recover.
