Global Change 478/578

Fall 2010

Review questions for lectures on 11/9, 11/16, 11/23, and 11/30. If you missed a lecture, be sure to get notes from someone who was in class; as always, the pdfs are not a complete representation of the lectures.

Lectures on 11/2, 11/30, and 12/2 will also be on the final - study guide to be posted separately.

Note the final will not be comprehensive, HOWEVER: if something is carried forward from another part of the semester into this final section, then you will be expected to know/remember it insofar as it related to what was presented in this last section. Examples woul dbe the cliamtic mechanism for future rainfall decreases in the SW, or the fact that temperature is generally better predicted by models than precipitation.

This guide is rather long, but it is complete. Virtually every question on the exam will be taken directly from something in this guide. It should help you sort through the main points in your lecture notes, my powerpoints, and the readings.

Impacts of Global Change on water resources in the SW US (Overpeck guest lecture)

How is rainfall expected to change in the SW US as climate warms? (explain, with climate/atmo circulation specifics; which season is critical here?)

A warming climate has significant implications for moisture availability and the hydrologic cycle; describe two of these. Why is warming a surer bet that precipitation changes?

What proportion of Arizona's water comes from surface flows (rivers)? What is the dominant use of water in AZ?

What trends have already been observed that lead us to concern about water in the west? (snowpack, rain vs snow, and length of warm season)

What does it mean to say that the current Colorado River water budget is "over-allocated"? Why is this the case? In the future, climate change will likely amplify this problem - why? What is the best estimate of the change in CR flow by 2050?

Are Arizona's rights to Colorado River water considered junior or senior (and what's the difference)? If we lose this water, will our taps quickly run dry? Why or why not?

We expect that on average, future conditions in the SW will be drier than normal. But what have we learned from tree-ring data that causes even more concern?

How is a warmer, drier climate affecting regional forests? (three ways: death by drought, beetles, and fire)

Land that has lost its vegetation tends to produce more dust; so does land that is under development for energy resources or has new roads for other reasons. Why is dust production in the West important for hydrology? What 2 critical impacts of dust on hydrology have been observed already?

Impacts of Global Change on Agriculture

Describe (in a sentence each) 2 of the biggests ways in which agriculture is a major contributor to global change.

If you want to reduce your carbon footprint, is it more effective to eat locally or eat vegan (no animal products)? Why?

Give two examples of how plants respond directly to increasing CO2. Why are these responses thought to be more important for agricultural than for natural ecosystems?

How are these direct effects studied? Is their impact on future ag productivity well constrained or poorly constrianed, and why does this matter?

How are pests likely to responsd in a warmer climate?

Give examples of factors beyond the direct climate response (of crops or pests) that are important for projecting future food availability.

What is a FACE experiment and why are they useful?

Give one specific example of how a crop's quality responds to increased CO2.

How does tropospheric ozone influence projections of future crop production? Are these influences likely to be mostly regional or will they be similar over the globe, and why?

Describe the general conclusions of the Battisti and Naylor paper on warming and future food availability. What specific climate change are they concerned about? Based on what you have learned in the early part of this class, is this a type of change that is likely to be well predicted by climate models or one about which there is a lot of uncertainty?

Impacts of Global Change on Health

Global change can influence human health in several ways, including directly and indirectly. Give 2 examples of direct effects (where climate acts on humans) and 2 specific examples of indirect effects (where climate acts on something else that influences human health).

Give examples of how climate variability (e.g. ENSO) influences disease or health?

Tropospheric ozone can influence human health in two very different pathways, Describe them (hint - link to ag lecture).

In the future, a warmer climate will certainly favor the spread of diesease-bearing mosquitoes, which will in turn lead to substantial expansion of diseases like malaria. True or false? Explain.

Why do microbes do better under warmer temperatures? How will this influence the development and spread of infectious disease?

How are allergy sufferers likely to fare under higher CO2 and warmer conditions? Give examples.

Give two examples of how drought can lead to negative health impacts for people.

Why do we expect air quality to decline in a warmer world?

Societal stability and human well being are linked; what evidence exists (that you saw in homework/discussion) for a climatic influence on societal stability?

Future sea level change (Overpeck guest lecture)

Identify three processes that lead to local changes in sea level. Identify two processes that lead to global changes in sea level.

How fast is sea level rising today (i.e. in the last ~15 yrs)? How does this rate compare to earlier assessments looking at changes over the 20th century?

What is the single largest cause of global sea level change at present?

What is the single biggest source of uncertainty in future sea level projections, particularly beyond 2100?

How much sea level rise is anticipated in the latest IPCC estimates for 2100? What critical process is not included in this estimate? Do IPCC projections tend to overestimate, underestimate, or accurately estimate sea level changes?

Based on new observations (e.g. Velicogna 2009), how is ice mass changing on the Earth's two large ice sheets? Is the rate of change constant?

Recent observations show the breakup of several ice shelves around Antarctica. Why do we think this is happening (be specific - hint: the air is still well below freezing temperature!). What mportant role do these ice sheleves play in the mass balance of the full ice sheet? Is this role well understood or just beginning to be quantified?

If we stopped burning fossil fuels today, sea level would continue to rise for centuries, even a millennium. Why? How much is expected for a quadrupling of CO2 (IPCC, total amount) and how long does this full change take to occur?

What glaciological observations are changing how people think about rates of future sea level change? (A complete answer here would include both ice processes - how is it that ice sheets melt so fast? - and ice mass observations).

Name a country (and its general location) that may disappear by 2100 from sea level rise.

Describe 2 reasons why many coastal areas are more susceptible to flooding under future climate change?

Describe the sea level and climate situation at the last interglacial. (when was this?). How does evidence from the last interglacial relate to future sea level projections? (amount as well as source of the water)

Give another example of a previous warm period, with global temperature and sea level change estimates.

Note the "key numbers" figure in your lecture notes (last page) - these are all fair game.