Environmental change Flashcards
Who is James Lovelock?
He came up with the Gaia theory
He is a British atmospheric scientist
He invented electron capture detector
He discovered the presence of CFCs in Earth’s atmosphere
What is Gaia?
A collection of negative feedback loops that stabilise the Earth’s physical environment. The physical environment is maintained in a condition favourable to life
What are the issues with the Gaia theory
It seems to require cooperation among organisms to stabilise Earth’s physical conditions
–> Conscious cooperation would involve mysticism –> unconscious cooperation could not have evolved
What is daisy world?
A computer simulation of a hypothetical world inhabited by patches of black and white daisies
What was the purpose of daisy world?
To show that organisms can unconsciously cooperate to regulate temperature and that no mystical cooperation is needed
What is the CLAW hypothesis?
It proposes a negative feedback loop that operates between ocean ecosystems and Earth’s climate. It specifically proposes that particular phytoplankton that produces dimethyl sulfide are responsive to variations in climate forcing and that these responses act to stabilise the Earth’s atmosphere.
List five types of negative global change
1) Exploitation
2) Land-use change
3) Fragmentation
4) Acidification
5) Global warming
List problems caused by humans
1) Over harvesting
2) Habitat loss as demand for agricultural land grows
3) Habitat fragmentation
4) Introduced species
5) Pollution
6) Global warming and climate change
What is the only known species to be wiped out by one organism?
The Stephen’s Island Wren was wiped out by the lighthouse keeper’s cat, named Tibbles.
What is an example of competitive exclusion in action?
The red and grey squirrels (don’t forget the Gurnell reference!)
List some large positive amplifying feedbacks
1) Vanishing arctic ice
2) Warming wetland Peat
3) Melting Permafrost
4) Amazon rainforest die-off
5) Clogging the ocean sink
6) Subsea floor methane hydrate
