The greenhouse effect

The greenhouse effect is natural and keeps Earth warm enough for life. Short-wave energy from the Sun passes through the atmosphere and warms the surface; the Earth re-radiates long-wave heat, and greenhouse gases (carbon dioxide, methane, water vapour) trap some of it.

• Burning fossil fuels, deforestation and farming add extra greenhouse gases.
• This enhanced greenhouse effect traps more heat and drives global warming and climate change.

Your carbon footprint

A carbon footprint is the total amount of greenhouse gases (measured as carbon dioxide) produced by a person, product or activity. It comes from travel, home energy, food and the goods we buy.

• You can reduce it: walk or cycle, use public transport, insulate your home, eat local and seasonal food, and buy less.
• Individual choices add up nationally — this is why governments set targets to cut emissions.

Which gas?

Environment, people & economy

Climate change has knock-on effects across three areas:

• Environment: melting ice caps and glaciers, rising sea levels, more droughts, floods and storms, loss of habitats and species.
• People: flooding of low-lying homes, water shortages, spread of disease, "climate refugees" forced to migrate.
• Economy: damage to farming and fishing, costly flood defences, disrupted trade and lost tourism income.

Environment, people or economy?

Reduce, reuse, recycle

The waste hierarchy ranks how we deal with waste, from best to worst. The three most sustainable options are the "three Rs":

• Reduce (best) — use fewer resources in the first place, e.g. less packaging.
• Reuse — use an item again, e.g. a refillable water bottle.
• Recycle — process waste into new products, e.g. glass, paper, cans.

Below these come recovery (e.g. energy from waste) and, worst of all, disposal in landfill.

Reduce, reuse or recycle?

Tap an action, then tap the group it belongs to.

Evaluating wind farms

Switching from fossil fuels to renewable energy cuts greenhouse gas emissions. To evaluate a source you weigh advantages against disadvantages. Take wind farms:

• Advantages: no greenhouse gases once built, wind is free and never runs out, farmland below can still be used.
• Disadvantages: only generate when the wind blows (intermittent), some people find turbines noisy or ugly (visual pollution), and they can harm birds.

A balanced evaluation ends with a judgement: wind is a valuable part of the energy mix, but cannot supply firm power alone, so it works best alongside other sources.

Your turn — turbine output

Your turn — carbon cut

The 2015 Paris Agreement

Because climate change is global, countries must act together. At the 2015 International Climate Change Agreement in Paris (the Paris Agreement), nearly every country agreed to:

• Hold the rise in global average temperature well below 2°C above pre-industrial levels, aiming for 1.5°C.
• Set their own national targets to cut greenhouse gas emissions and review them regularly.
• Help poorer countries (LEDCs) with money and technology to cope with climate change.

Check your notes: exact signatory numbers and later updates change over time — confirm any figures your teacher uses against current class notes.

What did Paris aim for?

Mass tourism vs ecotourism

Mass tourism is large numbers of visitors to one place. It brings money and jobs but can cause harm:

• Environmental: litter, footpath erosion, damage to reefs and wildlife, extra flights adding to emissions.
• Cultural: loss of local traditions and tension with tourists.
• Economic: profits "leak" to foreign firms; jobs are often seasonal and low-paid.

Sustainable tourism tries to protect places for the future. A responsible tourist respects local culture, saves water and energy, and buys local goods. Ecotourism is small-scale nature tourism that conserves the environment and directly benefits local people.

Case study flag: CCEA expects a sustainable-tourism / ecotourism case study from an LEDC or MEDC (e.g. Costa Rica). Check any visitor numbers, income or dates against your class notes before quoting them.

Match each term to its meaning

Tap a term on the left, then its matching meaning on the right.

The responsible choice

The big ideas to know

You've covered all of CCEA Theme D — Managing Our Environment. Press Finish to see your score.