10.3- human effects on ecosystems

Question 1

what is a valid study

Answer 1

-one which has been properly designed to answer questions being asked

Question 2

what is a reliable study

Answer 2

-other scientists an repeat the methodology and obtain similar results

Question 3

the greenhouse effect

Answer 3

-the process by which gases in the earths atmosphere absorb and re-radiate the radiation from the sun, which has been reflected from the earths surface, maintaining a temperature at the surface of earth that is warm enough for life to exist

Question 4

climate change

Answer 4

-climate is average weather pattern in an area over many years
-increase in extreme weather events linked to the rise in global temperatures
-thinning of polar ice is an indication of climate change which could lead to flooding
-as it melts, water vol increases, as water gets warmer the volume also increases
-since industrial revolution we have burnt increasing qty of fossil fuels for energy, transport and electricity. this produces CO2
-another theory is that solar activity affects cloud formation
-almost impossible to show any casual links

Question 5

depletion of natural resources

Answer 5

-fish stocks in ocean are depleting
-if we take too many, they cannot breed and replenish populations and fishing becomes unsustainable
-enormous drifts nets are used and also fishing through breeding season

Question 6

what is CITES and how does it work?

Answer 6

-international agreement designed to protect endangered animals and plants by regulating trade in both the living organisms and the products they make
-organisms grouped into appendix 1,2 or 3 depending on how endangered they are, 1 meaning they are close to extinction and no trade is allowed
-however, many countries have not signed it and it only deals with trade agreements, not protecting ecosystems

Question 7

conserving global biodiversity

Answer 7

-sustainability depends on effective management of the conflict between human needs and conservation
-international organisations including the UN are working towards increased biodiversity
-conserving fish stocks can help= control size of mesh in fishing nets so only largest are caught, banning fishing during breeding szn, quotas on fishing fleets, banning catching endangered species.
-another way is to farm fish (aquaculture), produces greenhouse gases

Question 8

what does athropogenic mean

Answer 8

-produced by people
-e.g. athropogenic greenhouse gases

Question 9

scientific journals

Answer 9

• peer reviewed before being published
  -sent to other experts in the field
• if peer reviewers agree that the paper is valid and reliable, it will be published