4.4 Climate Change

Question 1

What do greenhouse gases do in the atmosphere?

Answer 1

Ghg absorb and emit long-wave radiation (trap and hold heat in atmosph)

Question 2

What are the ghg which have the largest warming effect within the atmosph?

Answer 2

Water vapour - evaporation of water bodies
CO2 - cell respiration and burning fossil fuels
(Removed via photosynthesis and absorption by ocean)

Question 3

Which ghg have less effect on greenhouse effect?

Answer 3

Methane - waterlogged habitats and landfills (ruminants gaseous waste)
Nitrous oxides - bacteria and vehicles

Question 4

What is the most abundant ghg in atmosph?

Answer 4

Water vapour (not human activity)

Question 5

What are the two factors which determine the impact of the ghg on warming the atmosph?

Answer 5

1. Ability to absorb long-wave radiation-
   (Greater absorption greater warming impact)
2. Concentration within atmosphere
   (Greater conc greater warming impact)
   (Conc of gas determined by rate of release and persistence in atmosph)

Question 6

What is methane’s impact of a greenhouse gas? (2)

Answer 6

Larger capacity to absorb long-wave radiation than CO2
less abundant

Question 7

What is water vapours impact as ghg?

Answer 7

Enters atmosph rapidly but only remain for short periods
(Compared to CO2 which persist for years)

Question 8

What is greenhouse effect?

Answer 8

Natural process whereby the atmosph behaves like greenhouse to trap and retain heat

Question 9

How does the greenhouse effect work? (4)

Answer 9

Traps heat within atmosph preventing rapid temp fluxuations
- Incoming radiation from sun is shorter wave (UV and visible)
- Surface of Earth absorb shower wave radaient and re-emits it at a longer wavelength
- ghg absorbs and re-radiates longer wave radiation and retain heat

Question 10

What percentage increase in CO2 lvls in atmosph since industrial revolution? (Around-abouts)

Answer 10

-38% increase

Question 11

What three things do scientists predict that an increase in ghg concepts will lead to an enhanced ghg effect?

Answer 11

• more frequent extreme weather conditions
• some area become more drought affected, whilst others become more prone to periods of heavy rainfall
• changes to circulating ocean currents (cause longer El Niño (warming) and La Niña (cooling)) events

Question 12

What does the evidence of Vostok station in Antarctica show?

Answer 12

• longest drilled, reaching back 420 000 yrs
• analysing bubbles trapped in ice historical CO2 lvl and air temperatures

Question 13

What does the data of Vostok ice core demonstrate?

Answer 13

• strong positive correlation between CO2 concs and temps
• fluctuating cycles of CO2 conc which appear to correlate within warm and ice ages
• current concs of CO2 are higher than at any time recorded in last 400,000 yrs

Question 14

What will an increase in atmosph CO2 cause in coral and molluscs?

Answer 14

Dissolves CO2 and threatens viability of coral reefs and molluscs

Question 15

What is the rising levels of atmospheric CO2 causing to pH in oceans?

Answer 15

Oceans acidification or pH
(Since industrial revolution pH dropped from 8.2 -> 8.1)

Question 16

How does decrease in ocean pH threaten the survival of marine organism that require calcium carbonate? (3)

Answer 16

• increase of conc of H+ ions mean less free carbonate ions for calcification
• shells and coral exoskeletons are likely to dissolve
• experiments shown increasing water acidity correlates with thinning of shells pf molluscs that exist in regions with high levels of dissolved CO2

Question 17

What are the consequences of ocean acidification? (3)

Answer 17

• disappearance of coral reefs could result in loss of shoreline protection and habitat (alter coastal ecosystems)
• loss in revenue for tourism and food industries
• invasive species of algae to flourish

Question 18

Arguments for climate change

Answer 18

-volstok ice core