GEO 011
**Warming is Associated with _____ of the Hydrological Cycle, and this Includes ______ in Precipitation Intensity and ______ in Dry Spell Length for Ma ?
Strengthening / Increases / Increases
How does global warming affect air pollution? Why?
Warming accelerates ozone production and promotes air stagnation, leading to increased tropospheric ozone levels.
Uncertainty in Future Warming is Due to?
> Uncertainty in future emissions -> Uncertainty in climate sensitivity -> Uncertainty in future population -> Uncertainty in energy demand -> "B=C, A=D, A=E" ~ Professor
Why are future projections of climate change uncertain?
Projections of climate change are uncertain because of we have access to a short climate record. Nonetheless, we can draw certain conclusions based on fossil fuel burning and climate models
If CO2 Quadruples, Our Best Estimate of How Much Earth Will Eventually Warm is?
6` C
Are the health impacts associated with climate change uniformly distributed across the globe? Who is more susceptible? Why?
Nay The poor because they do not have access to resources Poor infrastructure, lack of health care, lack of emergency response facilities.
What is permafrost? How is it expected to change in a warmer world? What are some of the impacts of permafrost melting?
Permanently frozen soil (contains methane in it, when it melts it releases the CH4) -> It's slowly going away (Melting) -> Bridge Collapse -> Pipeline Breakage -> Roadway Degradation -> Contamination of Surrounding Environments
What is the "faux pause"? What caused it? Is it truly indicative of a pause in global warming?
-> A period in time where temperatures didn't increase as rapidly over the past decade as they did in the prior decades. ->This led to a false notion where they believed was a "pause" in global warming. -> Natural factors caused it -> Background Volcanic Activity -> Short - Term reduction in Solar output -> Series of La Niña events, all of which had led to temporary surface cooling not taken into account in most model simulations. NO
What is El Nino Southern Oscillation (ENSO)? How does the tropical Pacific change during El Nino? La Nina? ****Why do we care about ENSO? Are future projections of ENSO certain? ********If not, what does this imply for regional climate change projections?
-> ENSO is a natural irregular oscillation of the climate system, involving inter-related changes in: -> SSTs, currents, and winds across the tropical Pacific. -> Warm water flows eastward accumulating off South America, Downwarding, Southeast trade winds reverse or weaken -> Pool of warm water positioned farther west than normal, Southeast trade winds stronger than usual, Strong upwelling of cold, deep water, and Sea surface cooler than normal in eastern Pacific. ----------------- NO
Scientists Estimate Climate Sensitivity Over the Last Several Centuries by?
-> Estimating Solar Variations from sunspots -> Estimating GHGs from ice cores -> Estimating volcanic eruptions from ice cores -> Estimating Past temperature variations form tree rings/ice cores
Coastal and low-lying regions are particularly vulnerable to climate change
-> Rising Sea Level -> Increased Hurricane Destruction -> Increased Coastal Erosion -> Larger Wave Heights
What are True Regarding Marine Protected Areas?
-> They restrict human activity for a conservation purpose -> They protect natural or cultural resources.
Ocean Feedbacks include?
-> Warmer ocean -> absorbs less CO2 -> Ocean acidification -> reduces CaCO3 production -> absorbs more CO2 -> Ocean acidification -> reduces CaCO3 production -> weakens biological pump -> absorbs less CO2 -> Decreased mixing of nutrients -> slows biological productivity -> weakens biological pump -> absorbs less CO2
How is precipitation projected to change? Why? How are floods and droughts projected to change? why?
-Increased winter precipitation in polar and subpolar regions -Decreased summer precipitation in mid-latitude regions -Decreased precipitation in subtropics -Increased precipitation near equator -Projected poleward shift of jet streams -Poleward expansion of Hadley Cell -Warmer atmosphere -Greater drought tendency in many regions -More frequent and intense flooding in many regions More heat > more evaporation > more precipitation
What is "climate sensitivity"?
-amount of warming that we expect to occur when there is a change in the factors that control climate. (increase in GHGs). Expressed in terms of how much surface warming will occur in response to a doubling of CO2 from pre-industrial levels (280 ppm)
What is the range of climate sensitivity, according to IPCC?
1.5 - 4.5 degrees celsius
What the best estimate of climate sensitivity?
3 degrees celsius
If CO2 doubles, Our Best Estimate of How Much Earth Will Eventually Warm is?
3` C
How has CO2 varied over geologic time scales?
500 MYA (mil. Years ago) CO2 levels were high, then fell, reaching a minimum 300 MYA at the height if the Permo-Carboniferous glaciations on Gondwana. After that, levels rose and fell, reaching another maximum 175 MYA in the late Triassic. They stayed relatively high though the next 100 MY (age of the dinosaurs reptiles lived in the Arctic) Since then, CO2 has fallen, reaching another minimum close to present day. aCombined with paleo-temperature data, proxy CO2 data provide a climate sensitivity of 2-5°C (4-9°F)
Does all of our CO2 emissions stay in the atmosphere? If not, where does it go? Has this accelerated or dampened climate change?
55% of the CO2 we emit "disappears" Dissolves in the ocean, and is incorporated in living biomass (photosynthesis) Nature has somewhat reduced the human impact on atmospheric composition and climate
What are positive feedbacks associated with the carbon cycle? Negative feedbacks? Which type of feedback dominates? What does this imply for future climate change?
A warmer land leads to increased growth and respiration of soil microorganisms (more CO2 byproduct ) Plants increase their growth in response to more CO2(CO2 fertilization) Positive If positive feedbacks often dominate, this says that the warmer land leading to the increased growth/respiration of soil microorganisms will feed into itself. It will overlap the negative feedback
In addition to coral, what other organisms are at particular risk of extinction due toz climate change?
Amphibians
How is extreme weather projected to change? Severe frosts? Heat waves? Intense rainfall events and flooding? While many regions are projected to become drier, scientists predict that even in these regions:
As climate changes, it is likely that the frequency and intensity of extreme weather events will change -Extreme weather is projected to become more common and exaggerated They are going to decline -Are likely to become: More intense More frequent Longer lasting -Greatest increase is predicted to occur in: Western US North Africa Middle East -Increases in the frequency of intense precipitation events and flooding -More moisture in a warmer atmosphere -Individual rain/snow events will become more intense -Longer dry spells will separate them
How were atmospheric concentrations of greenhouse gases (GHGs) different? Sea Level? Ice sheets? Earth's orbital configuration? (Slide 22)
CO2: 50% less of what it is today Methane: ⅔ of what it is today NO2: ⅔ of what it is today 120 meters (395 ft) lower than present day sea level Ice sheets covered much of Canada, Northernmost U.S, Scandinavia, And Europe. Summer sunlight at high northern latitudes was reduced Winter snow could survive winter Additional ice accumulated
Where do estimates of climate sensitivity come from?
Climate Models: They compare observations from "instrumental records" the past 160 years. Estimate the impact of both Human and Natural Forces.
How will climate change affect disease (Malaria, dengue, West Nile Virus)? Why? How is this related to mosquitos and other vectors?
Disease will spread Because insects and rodents that carry diseases range more widely as the climate barriers are lifted Disease carrying mosquitoes are spreading.
All stabilization targets require sharp _____ in CO2 emission following the peak, with the lower stabilization targets requiring ___ peak emissions.
Decreases / Sooner
What is an ecosystem? Why are they valuable? How does climate change affect ecosystems? Biodiversity? According to the IPCC, what is the most vulnerable ecosystem? Why? What is "coral bleaching"?
Defined as an interdependent community, consisting of plants, animals, microscopic organisms, & a complex physical environment. Assist us with provisions(food, medicinal products), environmental regulation, & cultural benefits. Pressures ecosystems in total to adapt or DIE. Climate change may lead to species extinction, which in turn would decrease biodiversity. Coral Reefs because of ocean acidification. Occurs when corals lose their symbiotic algae that gives them their color.
An Initial Change Causes the Climate to Cool. According to the Chemical Weathering Thermostat...
Precipitation will decrease, decreasing weathering and decreasing CO2 removal.
What are fossil-fuel emission scenarios? 4 Scenarios? What are they based on?
Fossil Fuel Scenarios are created in an attempt to learn more about an uncertain future, scientists create and evaluate a range of scenarios (4) for greenhouse gas emissions. This exercise helps them to determine the scope of consequences for a variety of possible future fossil fuel use scenarios (divided between business as usual scenarios and conservation/mitigation scenarios) . There are 4 different scenarios (a range of 21st century policies) each representing a group of emissions scenarios for the future called "Representative Concentration Pathways (RCPs)" that are based on their total "radiative forcing" by 2100. -Each RCP is created by integrated assessment models that accounts for climate affects, economic, land use, demographic, and energy considerations -Emission scenarios are based on population, energy demand, economic growth, and technological advances. -"business as usual scenarios" (8.5): assume ever increasing rates of fossil fuel use -"conservation/mitigation scenarios" assume some future reduction for use. RCP 2.6, RCP 4.5, RCP 6.0, & RCP 8.5 (only required to know 2.6 & 8.6) -RCP 2.6: Requires strong efforts of mitigation to reduce greenhouses concentrations before 2100 -RCP 8.5 (aka business as usual scenario) allows the greenhouse gas concentrations before 2100 to rise beyond the year 2100. This scenario is the closest to what might be considered business as usual they're based on their total "radiative forcing" by 2100.
How might climate change affect environmental refugees? Why?
If they can't adapt fast enough, they will die out.
Food Production is Expected to ______ With Modest Warming (< 3`C), But _____ With More Warming.
Increase/ Decrease
Under the Higher Emissions Scenarios, the Rate of Climate Change _______ the Natural Migration Capacities of Most Plants.
Is larger Than
How was the Last Glacial Maximum (LGM) different than today?
It is colder than today by 3 - 8 degrees
What is meant by climate change "uncertainty"?
It is inevitable when we have access to a short climate record.
What is the biological pump? Why is it important? How is it expected to change under additional global warming?
It is the part of the oceanic carbon cycle responsible for the cycling of organic matter formed mainly by phytoplankton during photosynthesis (soft-tissue pump), as well as the cycling of calcium carbonate (CaCO3) formed into shells It allows more CO2 to be absorbed at the surface. If the pump isnt present, this can mean that less CO2 is absorbed and less carbon in the carbon cycle Decrease nutrients at the surface, ocean acidification
What are MPAs? Are they effective at reducing fish and coral loss? Can they protect coral from global warming? Ocean acidification? If not, then what needs to be done?`
Marine Protected Areas Yes Nay Nay Reduce or eliminate CO2 emissions, and sequester CO2 before it goes into the atmosphere.
Under RCP8.5, how much warming does IPCC project by 2100? Under RCP2.6? Is the surface warming spatially uniform?
Most conservative scenario: 1.2-2.8 degrees centigrade Least conservative scenario: 3.8-6.8 degrees centigrade Most conservative scenario: 0.2-1.8 degrees centigrade Least conservative scenario: 2.5-4.6 degrees centigrade ---------------
How well did past IPCC projections do? (Slide 35) What does this imply? Does IPCC overstate the effects of climate change? (Slide 37)
Quite well! model projections (due to natural factors), projected warming is consistent w/ observations False claim that global warming has stopped but it was only masked by fleeting natural factors. No, it is actually understating the effects
In the Carbon Cycle, What Process is Represented by the Red/Blue Arrow?
Respiration/Photosynthesis
How is sea level projected to change by 2100? (Slide 67) Why? What are some of the uncertainties associated with IPCC projections of future sea level rise (e.g., crevices/moulins)?
Rise between 0.5-1.2 meters Water becomes less dense (expands) as it warms Melting of Ice Crevices/Moulins are cracks/fissures in ice sheets, which allow melting water to accumulate further into the ice sheet, allowing more to break off. New problems such as these are not accounted for in models yet.
What is the climate significance of sunspots? How are they related to solar intensity?
Sunspots have been measured since back when Galileo first was able to. The measurements demonstrate the temperature is rising since brighter light equals hotter regions. They relate to solar intensity because the more sunspots the more coronas, premises, and the more flares form. Once they form they radiate to earth and hit our atmosphere → intensity impact. More sunspots= brighter sun Less sunspots= dimmer sun
What is meant by a "business-as-usual" scenario? (Slide 26) A conservation/mitigation scenario? What is RCP8.5? RCP2.6?
The burning of fossil fuels as it is right now What the name says, we reduce or mitigate (same thing really) our fossil-fuel usage. (RCP2.6) Increasing fossil fuel use Representative Concentration Pathways Future reduction of fossil fuel use
IPCC Estimates of Future Sea Level Rise May Be...
Underestimated
What causes the delay in warming in response to a doubling of CO2?
The ocean takes longer to warm (ocean warming)
What is the chemical weathering thermostat? Is it a positive or negative feedback? (Slide 64)
The process that turns rocks into soil and dissolved salts in rivers. Atmospheric CO2 dissolved in rain forms carbonic acid, increasing weathering process Negative. Increased weathering (during warming) -> increased removal of CO2 -> reduction of initial warming
What is the carbon cycle? What are the main reservoirs of carbon?
The series of processes by which carbon compounds are interconverted in the environment, typically between the land, ocean and atmosphere -Atmosphere -Ocean -Vegetation and soil on land
With modest warming, how will food production change? Is this dependent on region? With more warming (>3C), how will food production be affected?
Undermine food supplies=more famine Yes Negative impacts for crops in all agricultural regions.
How are soil microorganisms related to carbon cycle feedbacks? (Slide 59) Plants? Phytoplankton?
They decompose organic matter and fart out CO2 Plants use CO2 to grow Take CO2 from the atmosphere, and die. As they decompose, IF they sink, this transfers the carbon to the bottom of the ocean.
What is a hysteresis loop? How are these related to ice sheets?
Two stable states in which the environment operates on. If the environment begins warming/cooling, the two stable states may be surpassed by two thresholds: the temperature for catastrophic ice sheet melting and the temperature for ice sheet regrowth. If the climate warms too much (past a threshold) ice sheets melting will become unstoppable
Is photosynthesis important? Respiration?
Yes, photosynthesis is responsible for the transaction of carbon between the land biosphere and atmosphere Respiration is responsible for the transaction of carbon from the atmosphere to the biosphere
