The Climate Crisis and Carbon Footprint

§Text Passage

1Summary 重點摘要

Greenhouse gases in the atmosphere trap heat; since the Industrial Revolution humans have burned fossil fuels, raising global temperature by about 1.1°C and bringing extreme weather and rising seas. A carbon footprint measures the direct and indirect emissions of a person or product; saving energy, green transport and spotting 'greenwashing' are ways to take climate responsibility.

2Vocabulary cards Vocabulary

3Step by step Steps

1. Step 1: Understand the greenhouse effectGreenhouse gases absorb and re-release heat, keeping the Earth warm, but when their concentration climbs too high the temperature keeps rising. Example: sunlight heats a parked car and the closed windows trap the heat, so the inside grows hotter and hotter; greenhouse gases are like those windows — the higher their level, the hotter the Earth. Understanding this explains why cutting emissions matters. In an exam, remember the distinction: the greenhouse effect itself is natural and keeps the Earth's average temperature at a liveable fifteen degrees Celsius or so; it is the over-strengthening by human activity that causes global warming.
2. Step 2: Know the evidenceClimate change is not a feeling but a scientific conclusion supported by decades of observation. Example: scientists at the Mauna Loa Observatory in Hawaii have measured for decades, and the Keeling Curve shows carbon dioxide rising from 315 to over 420 parts per million, still climbing. Trusting evidence rather than rumour is the basic attitude for discussing climate issues. Reading such a line graph has a method: first note the years on the horizontal axis and the unit on the vertical one, then the overall direction of the curve; single years rise and fall, but the decades-long trend keeps climbing, and that is the point the data makes.
3. Step 3: Measure a daily carbon footprintA carbon footprint measures the greenhouse gases our activities emit directly and indirectly, counted in carbon-dioxide equivalent. Example: enter your weekly travel, diet and electricity habits into an online calculator and get about four tonnes of carbon dioxide a year; the biggest item is the first target for cutting. Knowing where emissions come from tells you where to act. Note that a carbon footprint counts more than transport — electricity, diet and shopping all enter; testing again every few months and comparing the numbers shows whether the reduction actions are working.
4. Step 4: Compare food and goodsDifferent foods and goods can differ by dozens of times in the emissions of their production. Example: producing a kilogram of beef emits tens of kilograms of carbon-dioxide equivalent while the same weight of vegetables emits only a few; locally grown vegetables also skip long-distance transport. Choosing seasonal, locally produced food is the most direct low-carbon change in eating. Another telling figure: about one third of the world's food is wasted between production and consumption, so buying only what we need and finishing every meal is a very real cut in emissions too.
5. Step 5: Analyse impacts and climate justiceThe impacts of climate change are uneven: poor countries that emit the least often suffer the most — the problem of climate justice. Example: the Maldives averages only about one metre above sea level, so rising seas threaten the whole country; such nations emit little yet bear the greatest risk, which is why the world set up a climate fund to help them. In answering such questions, hold two points: these nations bear little responsibility for emissions yet suffer the greatest effects; because the two are unequal, richer countries have the duty to give money and technology.
6. Step 6: Practise mitigation and adaptationMitigation means cutting emissions, adaptation means adjusting life to changes that have already arrived; both must go together. Example: set the air-conditioner at 25–26°C, switch off lights when leaving, walk or take public transport instead of the car, and sort food waste for recycling — all doable mitigation; drinking extra water on very hot days is adaptation. Exams often ask for sorting: switching to electric cars and saving power are mitigation because they cut emissions directly; building sea walls and leaving low-lying areas early are adaptation because they answer changes already here.
7. Step 7: Spot greenwashing with critical thinkingGreenwashing means companies exaggerating or inventing green claims to attract customers, so we must learn to verify. Example: a brand claims 'eco packaging' but has only thinned its plastic bags a little and publishes no data; ask 'where is the evidence?' and check for third-party certification. Critical thinking keeps us from being misled by advertising slogans. Verification has three steps: check whether the claim carries concrete figures, whether the product bears a recognised green certification, and finally whether official or independent websites confirm the data; only with all three is the claim believable.

4Diagrams Diagrams

5Worked example Example

6Common mistakes Mistakes

7Quick check Quick check

8Recap Recap

• Greenhouse gases hold heat; burning fossil fuels keeps raising carbon dioxide and global temperature.
• A carbon footprint measures a person's, activity's or product's total emissions and can be estimated with a calculator.
• Climate change brings extreme weather and rising seas; poor regions that emit least often suffer most.
• Respond on two lines: mitigation (saving power, green travel) and adaptation (sea walls, urban greening).
• Think critically against greenwashing: demand evidence, check certification, and push real change by spending and speaking.