Mini-Lesson

A2 Option: Climate Change - Past and Present

This mini-lesson covers A2 1 Option D - Climate Change: Past and Present: natural climate change evidence and causes, lowland glacial landscapes and their landforms, current global climate change (human causes and impacts), and managing climate change through mitigation and adaptation.

This is one of four A2 1 options; you study two. Answer each question to unlock the next screen. Press Start.

Natural climate change

Evidence and causes

Climate has always changed. CCEA distinguishes evidence and causes:

Evidence - ice cores, pollen analysis and ocean-floor deposits.
Causes - astronomic (Milankovitch cycles - eccentricity, obliquity, precession), solar output variation, continental drift and volcanic activity.

You must also know the end of the last glaciation and the arrival of the Holocene.

Quick check

Evidence vs cause

?Which of these is a source of evidence for past climate change, rather than a cause of it?

Lowland glacial landscapes

Glacial and fluvioglacial landforms

Ice sheets erode, transport and deposit material, and their meltwater (fluvioglacial) reshapes lowlands. Key landforms:

Till and drumlins - unsorted deposits and streamlined mounds.
Eskers - sinuous ridges of sorted sand and gravel from subglacial meltwater streams.
Erratics - boulders carried far from their source.
Outwash plains and moraines (including ribbed moraines).

CCEA uses a regional case study of a lowland post-glacial environment (for example County Down), evaluating the benefits and problems of development there.

Sort it

Sort the climate factor

Tap a term, then tap the correct group.

🔬 Evidence

🌞 Natural cause

🏭 Human cause

Quick check

Naming the landform

?A long, winding ridge of sorted sand and gravel deposited by a stream flowing under the ice is a(n):

Calculate

Calculate — CO2 percentage rise

1Suppose atmospheric CO₂ rose from a pre-industrial 280 ppm to 420 ppm. Calculate the percentage increase.

%

Hint: ((420 − 280) ÷ 280) × 100 = (140 ÷ 280) × 100.

Current global climate change

Human causes and impacts

Recent, rapid warming is linked to human activity through the enhanced greenhouse effect - burning fossil fuels, deforestation and land-use change raising greenhouse gas concentrations.

Present and potential impacts include melting ice and rising sea levels, shifting climate belts and agriculture, more extreme weather, and threats to ecosystems and water supplies - felt in both MEDCs and LEDCs.

Match it

Match the climate term

Tap an item on the left, then its matching partner on the right.

Term

Meaning

Quick check

Enhanced greenhouse effect

?The 'enhanced' greenhouse effect refers to:

Managing climate change

Mitigation, adaptation and agreements

Two broad responses:

Mitigation - reducing the cause: carbon capture, renewable energy, cutting greenhouse gas emissions.
Adaptation - reducing vulnerability: flood defences, drought-resistant crops, water management.

You must evaluate international action, including the Kyoto Protocol and the role of the Intergovernmental Panel on Climate Change (IPCC).

Quick check

Mitigation vs adaptation

?Building higher sea defences to cope with rising seas is an example of:

Recap

The big ideas to know

Natural change: evidence - ice cores, pollen, ocean-floor deposits; causes - astronomic, solar, continental drift, volcanic

Glacial landscapes: till, drumlins, eskers, erratics, outwash plains, moraines

Current change: enhanced greenhouse effect; impacts on ice, sea level, weather, ecosystems

Managing: mitigation (carbon capture, cut emissions) vs adaptation; Kyoto Protocol, IPCC

You have covered A2 1 Option D. Press Finish for your score.

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You have worked through Climate Change: Past and Present for CCEA A-level Geography. 🎉

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