AQA Biology 4.7.3.5
Global warming and its effects on ecosystems
One change, a warmer Earth, spreads through the living world. Turn up the temperature and watch where species live, when they travel, and which habitats are lost.
Triple Science · Higher tier
Start here
A cold-loving animal.
A mountain hare lives where winters are long and summers are cool. Over many years, the summers where it lives become hotter.
If you had to guess, would the places it can live shift nearer the poles, or nearer the equator?
The cause, in brief
Carbon dioxide and methane are rising.
The levels of carbon dioxide and methane in the atmosphere are increasing, and this is contributing to global warming. Burning fossil fuels, cutting down forests and farming livestock all add to them. How these gases warm the Earth is in the chemistry lesson on greenhouse gases; this lesson is about what warming does to living things.
Turn up the temperature
Ranges move. Coasts flood. Some species drop out.
The map is a model: a cold-loving species on a lowland, a mountain species near a peak, and a salt marsh on the coast. Move the slider.
Distribution
Species that can no longer survive where they lived shift their range, towards the poles or to higher ground.
Migration
Migrating animals such as birds may arrive earlier, or travel to different places, as the seasons shift.
Habitats flooded
Melting land ice and the expansion of warmer sea water raise sea levels, flooding coastal habitats.
Biodiversity
Species that cannot move or adapt fast enough may become extinct, so biodiversity is reduced.
How sure are scientists?
Agreement from thousands of studies; uncertainty in the detail.
The consensus
The scientific consensus about global warming and climate change is based on systematic reviews of thousands of peer-reviewed publications.
The uncertainty
Climate is complex and predictions rely on models, so exactly how much and how fast each place will change is uncertain. The overall trend is not.
Think again · which ice
“Melting sea ice makes the sea level rise.”
Your call
ChooseWhich of these raises the sea level?
Sort
Cause or effect on living things?
Place each statement.
Tap a card, then tap the box it belongs in. Tap a placed card to take it back.
Command words in this lesson
- Describe
- Name each biological consequence and what changes.
- Explain
- Warmer, so a species can’t survive where it was, so it moves or is lost.
- Suggest
- Apply the idea to a species you haven’t met.
Key fact
Global warming changes the distribution of species, changes migration patterns, floods coastal habitats as sea levels rise, and can reduce biodiversity.
Key note · AQA 4.7.3.5
Global warming and ecosystems
- The levels of carbon dioxide and methane in the atmosphere are increasing, contributing to global warming.
- Distribution (where a species is found) changes: ranges shift towards the poles or to higher ground.
- Migration patterns change.
- Melting land ice and the expansion of warmer sea water raise sea levels, flooding coastal habitats.
- Species that cannot move or adapt fast enough may become extinct, reducing biodiversity.
- The consensus comes from systematic reviews of thousands of peer-reviewed publications; predictions carry uncertainty.
Photograph this card. Tomorrow, cover it and say each line first.
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Ask MrBadmus
Not sure what distribution means?
The warming map is a model with invented species and steps, not data or a prediction.