lec 22- climate change Flashcards
what is topsoil erosion?
the gradual wearing of the top layer of soil by human activities
what disrupts root mats in agriculture?
plow based agriculture, replaces deep rooted natives with shallow rooted grains
where is global land use change increasing the fastest?
in tropical regions like SE asia, S america, Africa
what is the single biggest threat to terrestrial biodiversity?
global land use change
why is appropriation of freshwaters bad?
because when irrigation is done to provide water in dry area, dissolved salts accumulate in the water which can enter aquifers (ground water)
what causes eutrophication?
nitrogen and phosphorus from agriculture and fertilizers leak into rivers and other water streams that result in plant growth on water while death of fish and animals
what can eutrophication lead to?
dead zones, which have low to no oxygen, causing dead animals
what are some pollutants that cause biodiversity loss?
-sulfur from mines causes low pH in water
-oil spills in water interfere with biological membranes
-pesticides in agriculture
how does the pesticide DDT affect birds?
causes weak and brittle egg shells which results in higher death counts
what does the ozone layer do?
absorbs UV radiation, if UV is not absorbed it can cause DNA damage
what destroyed the ozone layer at the poles?
CFCs & greenhouse gases, montreal protocol was made to lower use and stop usage
what causes infectious disease emergence?
deforestation, wildlife trade, and live trade/human consumption
what was the most deadly pathogen in human history?
chytrid fungus, caused over 500 species of amphibians to decline
what mainly causes climate change?
greenhouse gases
what is the relative warming potentials of GHG’s?
CO2 = 1
methane (CH4) = 25
nitrous oxide (N2O) = 298
HFC = 14,800
perfluorocarbon (CF4) = 6,500
sulfur hexafluoride (SF6) = 22,800
who are the top 3 GHG emitters in the world?
- china
- USA
- india
how much of land and oceans have the governments agreed to protect?
30% worldwide
what happens to biological events due to climate change?
they shift (events like migration, breeding, nesting, flowering)
what does biodiversity loss effect?
ecosystems and services and products provided to humans
