Good Learning Co.
SavannahYear 8
← Geography
GeographyWeather, climate and a warming world25 min★★★ difficulty

Climate change: the evidence and the causes

Climate has always changed. The question a geographer asks is sharper: how fast, and what is driving it this time?

Part of your national curriculum
  • Human and physical geography: Understand weather and climate, including the change in climate from the Ice Age to the present
  • Geographical skills and fieldwork: Interpret and analyse a range of quantitative and qualitative data, including statistical data on trends and relationships between geographical phenomena
  • Human and physical geography: Understand how human and physical processes interact to influence, and be influenced by, climate change

Lesson overview

What you'll learn in this lesson

Evaluate evidence for climate change and distinguish natural from human causes.

Key learning points

  • • The evidence
  • • Natural causes
  • • The enhanced greenhouse effect
  • • Effects that are already measurable

This lesson at a glance

  • 25 minutes
  • 21 parts to scroll through
  • 4 quick checks
  • Marked quiz at the end
  • Gentle pace: short sittings with pauses

Words to know

evidenceclimatechangedistinguishnatural

Scroll down — the lesson carries on below

Part 1 of 21 · Discover5%
1

Watch & discover

Part 1 of 21

Climate change: the evidence and the causes illustrationVisual introduction

Picture this

Climate change: the evidence and the causes

Climate has always changed. The question a geographer asks is sharper: how fast, and what is driving it this time?

In a nutshell

Evaluate evidence for climate change and distinguish natural from human causes.

2

Learning cycle

Part 2 of 21

Learning cycle 1 of 2

Part 1 · The evidence

A short piece of teaching, then a check to make sure it has landed.

3

Explore the idea

Part 3 of 21

Learn

The evidence

Ice cores from Antarctica and Greenland trap ancient air, giving temperature and carbon dioxide records going back around 800,000 years. Tree rings show growing conditions year by year. Pollen in peat and lake sediments records which plants grew where. Historical records include harvest dates and frost-fair paintings on the frozen Thames. Instrumental records since about 1850, plus satellite measurements of ice extent and sea level since the 1970s, give the precise modern picture.

4

Reset break

Part 4 of 21

Pause

That's sitting 1 of 5 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now
5

Explore the idea

Part 5 of 21

Learn

Natural causes

Milankovitch cycles change the shape of the Earth's orbit, the tilt of its axis and its wobble over tens of thousands of years, pacing the ice ages. Solar output varies slightly over roughly eleven-year sunspot cycles. Large volcanic eruptions inject sulphate aerosols that reflect sunlight and cool the planet for a year or two. These explain past change well, but they cannot account for the speed of the last century of warming.

6

Quick check

Part 6 of 21

Quick check

Which source gives a direct sample of ancient atmosphere?

Give me a hint
7

Quick check

Part 7 of 21

Quick check

Milankovitch cycles describe changes in

Give me a hint
8

Reset break

Part 8 of 21

Pause

That's sitting 2 of 5 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now
9

Learning cycle

Part 9 of 21

Learning cycle 2 of 2

Part 2 · The enhanced greenhouse effect

A short piece of teaching, then a check to make sure it has landed.

10

Explore the idea

Part 10 of 21

Learn

The enhanced greenhouse effect

Greenhouse gases let short-wave solar radiation through but absorb outgoing long-wave radiation, keeping the Earth about 33 degrees warmer than it would otherwise be. Burning fossil fuels for energy and transport, deforestation which removes carbon sinks, cement production, rice paddies and livestock have raised carbon dioxide and methane concentrations far above the range of the ice-core record, strengthening that trapping.

11

Explore the idea

Part 11 of 21

Learn

Effects that are already measurable

Global mean temperature has risen by over one degree since pre-industrial times. Sea level is rising from thermal expansion and melting land ice, threatening low-lying nations and coastal cities. Heatwaves, droughts and intense rainfall events have become more frequent. Species ranges are shifting polewards and uphill, growing seasons are lengthening in the UK, and coral is bleaching as oceans warm and acidify.

12

Reset break

Part 12 of 21

Pause

That's sitting 3 of 5 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now
13

Quick check

Part 13 of 21

Quick check

Why do volcanic eruptions cool the climate briefly?

Give me a hint
14

Quick check

Part 14 of 21

Quick check

Sea level is rising mainly because of

Give me a hint
15

Explore the idea

Part 15 of 21

Worked example

Worked answer: explain how ice cores provide evidence of past climate change (4 marks)

Snow falling each year traps tiny bubbles of the atmosphere and is compressed into annual layers of ice (1). Drilling a core and counting the layers dates each sample precisely, in some places back around 800,000 years (1). The trapped bubbles are analysed for carbon dioxide and methane concentration, giving a direct record of past greenhouse gas levels (1), while the ratio of oxygen isotopes in the ice indicates the temperature when the snow fell, so temperature and gas concentration can be compared over time (1).

16

Reset break

Part 16 of 21

Pause

That's sitting 4 of 5 done

Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.

Stop here for now
17

Challenge round

Part 17 of 21

Game · Sort it

Which of these are true?

Drag each card into the right column. Tap a card first if dragging is fiddly.

True

Not true

18

Challenge round

Part 18 of 21

Game · Fill the gaps

Finish the sentences

Choose the word that belongs in each gap.

Milankovitch cycles ____ the shape of the Earth's orbit, the tilt of its axis and its wobble over tens of thousands of years, pacing the ice ages.

19

Challenge round

Part 19 of 21

Game · Recall cards

Which piece of evidence best supports the claim that recent warming is human-caused?

Card 1 of 4

20

Mastery quiz

Part 20 of 21

Marked quiz

End of lesson quiz: Climate change: the evidence and the causes

4 questions, marked with the reasoning shown. No timer.

  1. 1. Which piece of evidence best supports the claim that recent warming is human-caused?

  2. 2. Deserts cluster around…

  3. 3. On a climate graph, bars usually show…

  4. 4. Tundra vegetation is low-growing mainly because of…

21

Lesson round-up

Part 21 of 21

Lesson round-up

Ready when you are

Quiz score

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Games

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Points this lesson

0

Best run

0 in a row

Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?

Ask Luna

Part 1 of 21 · Watch & discover

How this is going

  • Not looked at yet

    Understand weather and climate, including the change in climate from the Ice Age to the present

  • Not looked at yet

    Interpret and analyse a range of quantitative and qualitative data, including statistical data on trends and relationships between geographical phenomena

  • Not looked at yet

    Understand how human and physical processes interact to influence, and be influenced by, climate change

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