IB ESS HL 6.2.7 Climate change models Question Bank

Marking guidance:

Allow [1 max] for general description of negative and positive feedback either as a separate knowledge statement or explicitly in e.g.:
negative feedback occurs when increase in global warming promotes reduction/stabilization of global warming and positive feedback occurs when it promotes further increase in global warming;

Allow [2max] per loop given below.
Negative feedback loops;
(Increased temperatures...)
a....leads to increased evaporation...;
b. . . . which leads to increased cloud cover…;
c....which leads to greater albedo...;
(...which decreases global temperature)
(Increase in global temperatures/ $\mathrm{CO}_{2}$ concentrations...)
d....leads to increased rates of photosynthesis...;
e….which is assimilating more $\mathrm{CO}_{2} \ldots$;
f....which is a greenhouse gas/ thus less outgoing heat/emitted long-wave radiation is absorbed...;
(...leading to lower global temperatures/ $\mathrm{CO}_{2}$ concentrations)

Positive feedback loops:
(Increased global temperatures...)
g.... lead to increased evaporation...;
h....which leads to more water vapour...;
i....which is a greenhouse gas/absorbs outgoing heat/emitted long-wave radiation...;
(which increases global temperature);
(Increased global temperatures...)
j....leads to melting of permafrost/glaciers...;
k....leading to increased methane release...;
l....which is a greenhouse gas / absorbs outgoing heat/emitted long-wave radiation...;
(...which increases global temperature)
(Increased global temperatures...)
m....leads to melting of polar ice caps...;
n.... leading to reduced ice/albedo;
o….which leads to less reflection of incoming solar radiation…;
(which increases global temperature);
Note: Allow [4max] if only positive or only negative feedback is addressed.
Allow credit for any other valid feedback loops relating to ocean expansion/forest fires/desertification etc.
Credit appropriately annotated drawings.