Our Changing Weather and Climate

Weather today, climate over time

It is easy to muddle two words that sound similar. Weather is what the atmosphere is doing at one place at one moment: sunny now, raining this afternoon. Climate is the average weather of a place worked out over many years, which is why we can say a country is generally hot and dry even on a rainy day there. To study weather we measure elements like temperature, rainfall, wind and air pressure, and we track systems such as depressions and anticyclones that bring very different conditions. Climate, meanwhile, is changing, and human activity is a major cause. This module covers the difference between weather and climate, how weather is measured, the main weather systems, and why the climate is warming and what can be done.

Weather and climate words

Learn these five terms before you study the atmosphere.

Match each instrument to what it measures

Depression against anticyclone

Two pressure systems bring opposite kinds of weather. Tell them apart.

Weather or climate?

A place is described as having warm, dry summers and mild, wet winters, on average, across the last thirty years. Is this describing its weather or its climate?

• Its climate
• Its weather
• A depression
• An instrument

Why the climate is changing

The Earth naturally keeps warm because gases in the atmosphere trap some of the heat from the Sun, which is the greenhouse effect. The problem is that human activity, above all the burning of fossil fuels like coal, oil and gas, has added far more of these gases, so more heat is trapped and the planet is warming. The evidence for this is strong and widely agreed among scientists. The effects include rising sea levels, melting ice and more extreme weather. People can respond by using renewable energy such as wind and solar, using less energy, and protecting forests that absorb these gases. When you answer on climate change, name a cause, an effect and a response, and keep to what the evidence shows.

Pick the true facts about weather and climate

Select every statement about weather and climate that is true.

• Weather is the day-to-day state of the atmosphere
• Climate is the average weather over many years
• Burning fossil fuels adds greenhouse gases
• A depression brings dry, settled weather
• Climate and weather mean exactly the same thing

Order how rain forms

Put the steps of how rain forms in the correct order.

• The Sun heats water and it evaporates
• The water vapour rises and cools
• It condenses into tiny droplets, forming clouds
• The droplets join together and grow heavy
• They fall to the ground as precipitation

Complete the weather facts

The state of the atmosphere at one place and time is the _____. The average weather over many years is the _____. Rain, snow and hail are all forms of _____. A low-pressure system bringing wet, windy weather is a _____.

Your wardrobe against your whole year

Think of the difference between what you put on today and what hangs in your wardrobe for the whole year. Today you might grab a coat because it is pouring, or shorts because it is warm, and that single choice is about right now. But the wardrobe as a whole, with its coats, jumpers, shorts and sun hat, tells you what to expect across the year where you live. One is the moment; the other is the pattern over a long stretch of time. The difference between what the sky is doing today and what a place is generally like across many years is exactly the same. Mixing up the two is the commonest slip in this topic, so always ask whether a fact is about one day or about the long-run pattern.

Tap the ways to reduce climate change

Tap every action below that would help to reduce climate change.

• using renewable energy such as wind and solar
• planting more trees
• using public transport more
• burning much more coal

Work out the temperature range

On a summer day the highest temperature is 18 degrees and the lowest is 6 degrees. The temperature range is the highest minus the lowest. What is the range in degrees?

Read the weather and climate

Read each situation and choose the best answer.

• A forecast shows low pressure with rain and strong wind moving in. Which system is this?
• You want to describe the climate of a country. What information do you use?
• A town wants to cut its contribution to climate change. What helps?

Build a weather point

Choose the word for each gap to complete one accurate point about weather and climate.

Explain weather, climate and climate change

A friend keeps mixing up weather and climate and does not understand why the climate is changing. Explain it clearly.

• Explain the difference between weather and climate
• Explain how weather is measured
• Explain the difference between a depression and an anticyclone
• Explain the greenhouse effect and why the climate is warming
• Explain some ways people can respond to climate change