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
  • 17 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 17 · Discover6%
1

Watch & discover

Part 1 of 17

Watch first

Climate change: the evidence and the causes

An English teaching video on this topic from iNewittAll. Watch it, then scroll down for the lesson.

In a nutshell

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

2

Learning cycle

Part 2 of 17

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 17

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 since the late 1970s and sea level since the early 1990s, give the precise modern picture.

4

Explore the idea

Part 4 of 17

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.

5

Quick check

Part 5 of 17

Quick check

Which source gives a direct sample of ancient atmosphere?

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Quick check

Part 6 of 17

Quick check

Milankovitch cycles describe changes in

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Learning cycle

Part 7 of 17

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.

8

Reset break

Part 8 of 17

Pause

That's sitting 1 of 2 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

Explore the idea

Part 9 of 17

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.

10

Explore the idea

Part 10 of 17

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.

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Quick check

Part 11 of 17

Quick check

Why do volcanic eruptions cool the climate briefly?

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Quick check

Part 12 of 17

Quick check

Sea level is rising mainly because of

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Explore the idea

Part 13 of 17

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).

14

Challenge round

Part 14 of 17

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

15

Challenge round

Part 15 of 17

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.

16

Mastery quiz

Part 16 of 17

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. Which source gives a direct sample of ancient atmosphere?

  3. 3. Milankovitch cycles describe changes in

  4. 4. Why do volcanic eruptions cool the climate briefly?

17

Lesson round-up

Part 17 of 17

Lesson round-up

Ready when you are

Quiz score

Not sat

Games

Not played

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

Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Case study

Flooding on the River Calder

The town of Harbrook sits where a steep valley opens onto a flat floodplain. In December 2015, 120 mm of rain fell in 36 hours onto ground that was already saturated. The river rose 2.4 m in five hours, and 380 homes and 54 businesses flooded. Two roads and the railway closed for eleven days.

Geographers pointed to physical causes — steep slopes, impermeable rock, heavy rainfall — and human causes: moorland drained upstream, new housing built on the floodplain, and drains designed for smaller storms.

Since then the town has planted 40 hectares of woodland upstream, built leaky dams in small streams, and raised flood walls to 1.8 m. In the storm of 2020 the peak river level was 0.3 m lower and 40 homes flooded, not 380.

Written for Good Learning Co.

Reading questions

  1. List two physical and two human causes of the 2015 flood.
  2. Explain how planting woodland upstream lowers the river's peak level.
  3. Using the figures, judge how successful the scheme has been. Quote data in your answer.

  • Case study notes

    Writing

    Write the place, the facts and the figures from this lesson so you can revise them later.

    Half a page

  • Explain answer

    Writing

    Answer in full sentences, giving causes and effects. Use one figure or place name as evidence.

    8–10 sentences

  • Map or sketch

    Diagram

    Draw the map, cross-section or field sketch with a key, title and labels, then photograph it.

    1 map with a key

  • Data work

    Working out

    Plot your figures as a graph on paper and write one sentence about the pattern.

    1 graph + 1 sentence

Saved as you type.

Part 1 of 17 · 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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