Climate Change Basics
Understand that greenhouse gases absorb and re-emit infrared radiation from Earth's surface, slowing heat loss to space. Burning fossil fuels adds carbon dioxide and increases warming. Rising average temperatures change weather patterns, melt land ice and raise seas as meltwater enters the ocean and warmer seawater expands.
What a learner can do afterwards
- Describe the greenhouse effect: gases absorb and re-emit infrared radiation, slowing Earth's heat loss to space
- Explain that burning fossil fuels increases CO₂ in the atmosphere
- Name at least two consequences of global warming, such as changing weather patterns, melting land ice and rising seas
1 · Read
Climate describes weather patterns over many years. The atmosphere is the air around Earth. Sunlight warms land and ocean. They send energy upward as invisible infrared radiation. Greenhouse gases absorb some and send energy in all directions, including toward the surface. This slows heat loss to space. The natural greenhouse effect keeps Earth's surface warmer.
People burn coal, oil and natural gas for cars, factories, heating and electricity. These fossil fuels release carbon dioxide, or CO2, when burned. Extra CO2 increases greenhouse warming and raises Earth's average temperature. People's greenhouse gas emissions are the main cause of current global warming. Methane and water vapor are other greenhouse gases.
Warming melts more land ice, including glaciers and ice sheets. Meltwater can reach the ocean and add water. Warmer seawater also takes up more space: it expands. Both processes raise global sea level and increase coastal flood risk. Local sea-level changes also depend on factors such as land rising or sinking.
Two made-up school plans cut yearly CO2 emissions by 40 kg and 70 kg. Kilograms (kg) measure mass. To compare the cuts, subtract: 70 - 40 = 30 kg. These are practice numbers, not estimates for real schools.
Warming can change rain and snow patterns. Some places get more heavy rain; others have longer dry spells. In many snowy places, warmer air means less snow and earlier melting. Heavy rain and snowmelt can combine to add river water and raise flood risk. One flood alone cannot show its cause. Scientists compare long records and check other causes.
Walking or cycling instead of a petrol car trip can cut fuel use when the route is safe. Turning off unused lights saves electricity. It can cut fossil fuel use where power stations burn these fuels. Factories, heating and power plants can still release CO2. Families, communities, businesses and governments all have ways to reduce emissions.
Extra CO2 slows Earth's heat loss. Warming changes weather patterns, melts land ice and raises seas.
The readings were written for this dataset. The linked video, Climate change: Earth's giant game of Tetris - Joss Fong, is a TED-Ed lesson. Its licensing terms have not been verified.
More to read
Energy leaving Earth
Sunlight warms Earth's surface. Land and ocean then send energy outward as infrared radiation, which our eyes cannot see.
Greenhouse gases absorb some outgoing infrared energy and send energy in all directions. Some returns toward the surface. This slows heat loss to space and keeps the surface warmer than it would otherwise be.
Adding carbon dioxide increases this warming effect. The atmosphere does not need to become a physically thicker blanket. The change is in how energy moves through its gases.
Looking beyond one day
A cold morning can happen while Earth's average temperature is rising. Weather describes short-term conditions; climate describes patterns across many years.
Scientists compare long records and measurements from many places. They examine temperature, rain, snow and ice. They also study how energy enters and leaves Earth to understand the causes of change.
Burning fossil fuels adds carbon dioxide to the air. People's greenhouse gas emissions are the main cause of current global warming. One local weather event cannot establish or rule out that long-term change.
Two reasons seas rise
Warming changes both land ice and ocean water.
Glaciers and ice sheets store water on land. When more ice melts, meltwater can reach the ocean and add water. Seawater also expands as it warms. Both changes raise global sea level.
Higher seas can make coastal flooding more likely. Sea-level change is not equal at every coast. Land can rise or sink, and ocean conditions vary. Studying one shoreline means checking those local factors as well as the global rise.
Using less fuel safely
Replacing a short petrol car trip with walking or cycling can reduce fuel use. Children should follow an adult's guidance, use safe routes and wear a helmet when cycling.
Turning off an unused light saves electricity. Where power stations burn fossil fuels, using less electricity can also reduce fuel use. Electricity can come from other sources, including wind and sunlight.
Cars and homes are not the only sources of emissions. Factories and power systems also need changes. Families, communities, businesses and governments can act on different sources.
Describing climate change
Climate change is a lasting change in climate patterns. These patterns include average temperature and the usual amounts and timing of rain or snow.
Global warming is a rise in Earth's average temperature. It does not mean every place becomes warmer every day. Places can experience different changes, including shifts in wet and dry periods.
To describe a change, say which pattern changed, where it changed and what period the records cover. A hot afternoon describes weather. A rise in average temperature across many years describes a long-term pattern.
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2 · Watch
Take it off screen
Where it sits
Learn first
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.