Reforestation, sustainable resources and biofuelsSpec 5.26
In short
Humans need resources such as timber, food and fuel, but using them can damage ecosystems. Reforestation and the use of sustainable resources, including biofuels, are examples of effective management of this conflict. A resource is sustainable if it is replaced as fast as it is used, so that it is available for future generations.
There is a conflict between human needs (energy, wood, farmland, food) and conservation of ecosystems and biodiversity. Sustainable use meets present needs without reducing the ability of future generations to meet theirs.
| Approach | How it helps | Possible problems |
|---|---|---|
| Reforestation (replanting trees, for example after logging) and sustainable forestry (felling only as many trees as are replaced, replanting, selective felling, coppicing) | Timber is still available; trees remove CO₂ by photosynthesis, store carbon, protect soil and provide habitats | Planting a single species (monoculture) supports less biodiversity than natural forest; young forests store less carbon than mature forest; needs time and land |
| Biofuels: fuels made from recently grown biomass, such as ethanol from sugar cane or maize and biodiesel from oil crops | The CO₂ released on burning was taken in by the crop, so they may be close to carbon neutral; reduce use of fossil fuels | Growing crops needs land, which may be taken from forest or food crops; fertilisers, machinery and processing use energy and release greenhouse gases; monocultures reduce biodiversity |
| Other sustainable resources (renewable energy, sustainably sourced timber and fish with quotas) | Reduce the use of finite resources and the release of greenhouse gases | Cost, land use, and impact on habitats must be balanced |
The best management usually involves compromise: for example, using waste plant material or non-food crops grown on poor land for biofuels, rather than clearing rainforest to grow oil palm, and combining reforestation with the protection of mature forest.
A good answer to an evaluation question gives one benefit and one drawback, and then a judgement about how well the conflict has been managed.
Quick check
Name two sources of indirect evidence for past climates.
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Pollen in peat bogs and tree rings (dendrochronology). Ice cores are also acceptable.
What is an anthropogenic cause of climate change?
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One caused by human activity, such as burning fossil fuels or deforestation.
Which processes in the carbon cycle remove CO₂ from the atmosphere?
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Photosynthesis and dissolving in the oceans.
State one limitation of climate models.
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Climate is a complex system with feedback loops that cannot all be included accurately.
Why might the conclusions about climate change differ between organisations?
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Vested interests, funding or selection of data can influence the conclusions.
Written and checked against the Edexcel International A Level Biology (YBI11) specification · Updated October 2026