Autumn 2013
Name ___________________________ Name ___________________________
Name ___________________________
1. This map gives the current average annual temperature for major cities in North America.
a) In 2100, what current west coast city would Seattle be
most similar to, if present trends continue and temperatures
increase by 6.4 degrees?
Seattle+6.4=11.1+6.4=17.5…San Diego or Southern CA at least
b) The King County is home to 1.9 million people. Comment
on the consequences for these individuals.
Hotter, more AC demand, sanitation can decrease with added heat, more stress on plants, agriculture in state might suffer, etc.
2. In Washington, most water for crop irrigation and drinking comes from snowpack. Comment on how declining snowpack is likely to affect:
a) Seattle
We would likely have less water – less to drink, less to bathe, less to water gardens/lawns/agriculture.
(Created by Freeman; 2011) b) Washington state’s fruit industry
Fruit industry will have less water for irrigation
– fruit will not develop as well, industry will suffer, farmers will lose business, customers will have less produce.
3. In Lake Washington, Daphnia are the major food source for most fish. They are herbivores and mainly feed on diatoms. The regression lines on the graph show recent trends in the timing of population peaks for diatoms and Daphnia .
a) What can you conclude from this graph?
Diatom bloom is happening earlier and daphnia peak is not changing
b) What do the data imply about the future of the Daphnia population?
Daphnia are likely to end up with less food (because they eat diatoms) so Daphnia populations may suffer.
4. This graph shows the % change in average yield of wheat in key wheat-producing
(From Winder & Schindler; Ecology 2004) countries from 1980-2008, plotted as the difference between actual yields and projected yields in the absence of climate change. When the average is negative, it means that the country produced less wheat than they were projected to produce. a) Much of Washington’s wheat crop is exported. What do these data imply for Washington’s wheat farmers?
WA wheat farmers are faring better than wheat farmers from other nations (positive change rather than negative). If exportation continues WA farmers should export more, make more money, and be better off.
b) In extremely hot summers, yields of Washington wheat drop. But over
the next 100 years, the impact of extreme heat is projected to be offset by the impact
of increased atmospheric CO
2
on wheat yields. Explain why.
CO2 can be a fertilizer (plants need CO2 for photosynthesis) so higher CO2 could lead to more growth but higher temperatures can also destroy growth so the two will likely offset each other.
(From Lobell et al; Science 2011)
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5. Feedbacks describe situations where an event has an effect that “feeds back” to the original event. For example, if climate change causes “X” and “X” causes more climate change, the feedback is considered a positive feedback.
On th e other hand, if climate change causes “Y” and “Y” reduces climate change, the feedback is considered a negative feedback. Fill out the following table with this in mind.
Event
What is a possible impact of this event and how does it affect climate change?
…decreases in Net Primary
Production (NPP) in marine
Decreased NPP will mean more CO2 in the atmosphere-this will accelerate warming.
environments.
Climate …increases in tree growth in change is causing… old growth forests in the
Pacific Northwest.
…increases in fire frequency and severity in the Western
Cascades.
Increases in NPP in forests will increase the carbon sink and remove more CO2 from atm.
More fires (or more severe fires) will decrease plant matter (facilitating less carbon assimilation) and add
CO2 to atm.
…the sea level to rise.
Could reduce land surface and terrestrial NPP, could increase marine NPP, could have no effect on NPP if those balance…
6. Salmon are sensitive to heat stress. After being handled, the body’s hormones must return to equilibrium to continue regular function. The graph shows the time salmon needed to return to equilibrium (after being handled) when placed in 13 o C, 19 o C, or 21 o C water.
a) Based on this analysis, how will climate change impact salmon
populations in Washington state?
Warmer temperatures will increase the recovery time so salmon will spend more time out of equilibrium (ie more time in stressful conditions). Populations could suffer declines.
Is this a Positive Feedback, a
Negative feedback, or neither?
Positive feedback
Negative feedback
Positive feedback
Positive, negative, or neither – largely unknown b) Comment on the implications for Washington’s fishing
industry.
Fishing industry could suffer if populations crash or if fish are more fragile because water temperatures are too high.
(From Gale et al; Fisheries Research 2011)
7. Recent work on Mount Rainier has documented changes in the number of trees becoming established in alpine meadows —treeless habitats dominated by wildflowers. The data graphed to the right are from the ranger station at Sunrise. (Sunrise is the highest visitor center at the park and is within the range of alpine meadows.)
a) What do these data suggest about the distribution of trees?
Trees are expanding their ranges, up in elevation
– into the subalpine meadows
b) If climate change continues, what is the probable fate of alpine
(From Rochefort and Peterson; Arctic & Alpine Research 1996)
meadow habitats on Mount Rainier?
Meadows will decline in abundance because trees are “invading” therefore meadow plants may be outcompeted.
8. Consider the following reaction: CO
2
(g) + H
2
O(l) H + (aq) + HCO
3
(aq)
a) Explain why seawater is becoming more acidic. pH measures H+ concentration – high H+ means acidic conditions.
b) Oysters have calcium carbonate (CaCO
3
) shells. Rates of CaCO
3
deposition in marine organisms slow when pH drops. Discuss the implications for Washington’s shellfish industry.
Shellfish will not form shells as easily or shells will decrease in thickness – this will leave the animals more vulnerable to predation or damage and the shellfish industry may suffer lower production.
********* Please turn the completed exercise in to any T.A. (and make sure that your names are legible!) *********
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