Environmental Change / Global Warming & Human Population / Waste & Land Use & Peat Bogs & Deforestation

Which environmental changes can affect species distribution?

Changes in temperature, availability of water and composition of atmospheric gases.

What can cause environmental changes?

They may be seasonal, geographic or caused by human activity.

How can environmental change alter species distribution?

Conditions may become more or less suitable for survival and reproduction, causing populations to increase, decrease or move into/out of an area.

Why are humans producing more waste?

The human population is growing rapidly and standards of living are increasing, so more resources are used and more waste is produced.

How can water be polluted?

By sewage, fertiliser and toxic chemicals.

How can air be polluted?

By smoke and acidic gases.

How can land be polluted?

By landfill and toxic chemicals.

How can pollution reduce biodiversity?

Pollution can kill organisms or make habitats unsuitable, reducing population sizes and the number of species present.

How do humans reduce land available for other organisms?

Through building, quarrying, farming and dumping waste.

Why does destruction of peat bogs reduce biodiversity?

It destroys habitat, reducing the variety of plants, animals and microorganisms living there.

Why does destroying peat bogs contribute to climate change?

Decay or burning of peat releases carbon dioxide into the atmosphere.

Why are peat bogs important carbon stores?

Peat contains large quantities of stored carbon, so preserving it prevents that carbon being released as carbon dioxide.

Why are tropical forests cleared?

To provide land for cattle and rice fields and to grow crops for biofuels.

How can deforestation increase atmospheric carbon dioxide?

Fewer trees means less photosynthesis, so less carbon dioxide is removed from the atmosphere. Burning/decay of cleared vegetation releases carbon dioxide.

How can deforestation reduce biodiversity?

It destroys habitats, causing populations to decrease and potentially leading to extinction.

Which gases does AQA specifically identify as contributing to global warming in Ecology?

Carbon dioxide and methane.

Give biological consequences of global warming.

Possible consequences include changes in species distribution, changes in migration patterns, altered biodiversity and extinction of species unable to adapt/migrate sufficiently rapidly.

Why can climate predictions contain uncertainty?

Climate is a complex system with many interacting variables, and future emissions and environmental responses cannot be known exactly.

What supports the scientific consensus on global warming and climate change?

Systematic reviews of thousands of peer-reviewed scientific publications.