GEO 11 test 2

example of fingerprints

Natural factor: changes in solar output and volcanic eruptions human factors: greenhouse gases and industrial aerosols

climate sensitivity

amount of warming that can be expected when there are changes in the various factors that control climate (increase in GHGs)

climate model examples

climate proxy data: tree rings/ice cores(estimate how the northern hemisphere temperature varied during past centuries)

How does the tropical Pacific change during El Nino? (2B.p2) La Nina?

-- During El Nino: - Trade winds in eastern/central tropical Pacific weaken (or even reverse) - Little to no upwelling of cold sub-surface ocean water in eastern equatorial Pacific - Warm water spreads out over much of tropical Pacific ocean surface -- During La Nina: - Trade winds in eastern/central tropical Pacific are stronger - Strong upwelling of cold, deep water in eastern/central equatorial Pacific

As climate has changed in the geologic past, ecosystems (plants, animals, microscopic organisms, etc.) have shifted in response. How is past climate change different than projected future changes? (3.p12) How is this related to migration rates? (3.p29) What does this imply for ecosystems, biodiversity and individual species? (3.p30) Under 2K and 4K warming, what percentage of plant and animal species will be at risk of extinction, respectively? (3.p30)

-Past climate change were slower than the projected future changes human activity is already pushing ecosystem resilience, and many lead to species extinction if they cannot adapt or migrate fast enough -Rate of climate change exceeds the natural migration capacities of most plants and animals for the higher-emissions scenarios -20%-30% of plants and animals will be subject to increased risk of extinction if global temp. Rise to 2.0 C above the pre-industrial -40%-70% at risk with temperature rise of 4.0C & extinction is irreversible

According to IPCC, what is the best range of climate sensitivity?

1.5-4.5 c

sea level during Last Glacial Maximum?

120 meters lower

How is sea level projected to change by 2100? Why? (2B.p26) How much will sea level rise with an eventual melting of Greenland / West Antarctic ice sheet? (2B.p27) What are some of the uncertainties associated with IPCC projections of future sea level rise (e.g., crevices/moulins)? (2B.p29) Will sea level rise happen everywhere over the globe (note the rebound effect)? (3.p57) How does sea level rise affect land and Gross Domestic Product (GDP)? (3.p10)

2100 projections of sea level = 0.5-1.2 meters (because melting of land ice/water expansion) Melting of greenland ice sheet: 5-7 meters increase Melting of West Antarctic: 5 meters increase Some uncertainty associated is Crevices(Moulins) are crack in the ice sheet let water go under the ice sheets' base and can cause big chucks of ice side off into the ocean thus increasing sea level. These Crevices are hard to tack down and we do not know when or how much ice will break off. Sea levels has risen except in regions (eastern Canada) where rising of coastline has happened due to Earth's slow rebound from ice age Any sea level rise will cause sizeable losses of land and GDP

best estimate of climate sensitivity?

3.0c (5.4f)

how are representative Concentration Pathways (RCPs) defined?

4 different ways based on their total radiative force by 2100 --business-as-usual:means that there is no regulation or limit on CO2 emission release --mitigation/conservation: is a scenario where there is regulation to reduce CO2 emission and thus reducing the temperature of earth --RCP8.5: is business-as-usual scenario --RCP2.6: reduction of GHG concentration (Mit/con) scenario

How has CO2 varied over time?

500 MYA (high) then fell 300 MYA (Min) at the height of the permo carboniferous glaciations on Gondwana 175 MYA (max) in the late Triassic 100 MYA (stayed high) through the age of the Dinosaurs) since then Co2 fallen reaching another min -present day

What is an ecosystem? List ecosystem boundaries delineated by climate. (3.p14) Why are they valuable? (3.p11) How does climate change affect ecosystems? Biodiversity? (3. p12) According to the IPCC, what is the most vulnerable ecosystem? Why? (3.p16) What is "coral bleaching"? (3.p18) Why coral reefs and wetlands are important? (3.p15, 3.p13) Besides coral, what other animal species will be at particular risk of extinction under continued climate change?

An ecosystem is an interdependent community of plants, animals, and microscopic organisms, and their complex physical environment. Ecosystems are valuable to humanity because they assist us with: Provisions Food (seeds, fruits, game, spices); fiber (wood, textiles); medicinal and cosmetic products (dyes, scents) Environmental Regulation Climate and water regulation, water and air purification, carbon sequestration, protection from natural disasters, disease, and pests. Cultural Benefits Appreciation of, and interaction with, the natural world; recreational activities. Human activity is already pushing ecosystem resilience, and may lead to species extinction if they cannot adapt or migrate fast enough.(losing biodiversity) IPCC concludes that "coral reefs are the most vulnerable marine ecosystem with little scope for adaptation". Coral bleaching—the loss of algae that live in a symbiotic relationship with the coral & give it color —is linked to exceptionally hot ocean temperatures. The importance of wetlands that they are biologically diverse, providing homes for endangered species and a refuge for migrating birds. Coral reefs are important because they are among the most diverse ecosystems. Polar bears, amphibians (the golden toad), and birds are in danger of being extinct.

How is extreme weather predicted to change? (2B.p32) Severe frosts? (2B.p33) Heat waves? (2B.p34) Intense rainfall events and flooding? Dry spells? (2B.p35) Hurricanes? (2B.p40)

Because of more warming, it changes the frequency and intensity of extreme weather. Severe frosts (very cold nights) will decrease while heat waves (very hot days) will become more intense, more frequent, and long lasting. Water cycle is connected to global warming so the frequency of wet and dry days increased. Warming has a big impact in creating Hurricanes in Cat 4-5 level (strongest levels) plus with strong level of winds and sea level rise to deal more damage in the tropical Atlantic area.

where do estimates of climate sensitivity come from?

Climate models are compares to observations over the past 160 years; study responses to changes in nautral factors governing climate in previous centuries

How will climate change affect disease (Malaria, dengue, West Nile Virus)? Why? How is this related to mosquitos and other vectors? (3.p51) Are the health impacts associated with climate change uniformly distributed across the globe? Who is more susceptible? Why?

Diseases will spread because the barrier will be broken by climate change. Rodents and insects w/ diseases will range/spread more widely Disease-carrying mosquitoes (typically in warmer climes) spreading to extratropics due to warmer winters (West Nile virus) Warm temperatures lead to faster malaria-carrying parasite reproduction cycles Health impacts will not be globally uniform Poor nations will be more susceptible along with children, elderly, urban poor and low lying coastal areas Unlike wealthy nations, they are susceptible due to inadequate access to air conditioning, infrastructure (clean water, electricity), health care, and emergency response facilities

What are fingerprints?

Distinguish human and natural climate impacts

What is El Nino Southern Oscillation (ENSO)?

El Nino Southern Oscillation (ENSO): natural irregular oscillation of the climate system, involving inter-related changes in sea surface temperatures (SSTs), ocean currents, and winds across the tropical pacific.

What are the characteristics of ENSO projections (climate overall? ENSO magnitude?) Are ENSO projections certain?

El nino is associated with- weakening/reversal of southeast trade winds, warmer water in the eastern tropical pacific, reduction in cold upwelling off coast of south america, wetter conditions` in southern US

what causes delay in warming in response to doubling of CO2?

Equilibrium climate sensitivity: takes into account the fact that the full amount of warming, ini response to an increase in GHGs, may not be realized for many decades, due to delayed ocean warming

what is the" faux pause"?

Faux Pause: explains that there was not a pause in global warming and it si not smiluated by most model simulations.

How are floods and droughts projected to change? Why?

Floods and droughts are expected to increase and become more intense due to decreased summer precipitation and increased evaporation

With modest warming, how will food production change? Is this dependent on region? With more warming (>3oC), how will food production be affected? (3.p 47-48) Note the effect of socioeconomic development. (3.p50)

Food production changes= short term positives, long term negatives Famine due to warmer temperatures and less precipitation and less crops Diseases and wildfires Dependent on region since some regions (US, Europe, Canada) will benefit @ moderate levels of additional warming (increased crop/livestock) whilst many tropical/subtropical regions suffer (decrease of key crops) with decreased rainfall/warmer temperatures Socioeconomic development could partially/completely offset negative impacts on food supply Projections of # of undernourished people by 2080 range from reduction of 100 million to an increase to 1.3 billion (currently 820 million people)

13. What is a hysteresis loop? Tipping points? How are they related to "abrupt climate change"? Be familiar with the case of ice sheets

Hysteresis loop: path back to the original condition can be much different than the path that led the system to the altered state Two-stable states: (also the tipping points) Threshold temperature for catastrophic ice sheet melting Threshold temperature for ice sheet regrowth. Climate will eventually tip into an ice-free state Potential tipping points include: Ice sheets collapsing Cease of conveyor-belt-like mixing of [Atlantic] warm waters to polar latitudes Tropical rainforests unrecoverable under warmer global climate conditions Ice sheets have been shrinking

how has CO2 varied over geological time scales?

Ice cores show fluctuations in CO2 and temperature have gon hand in hand.

Under climate change, what are the threats to coastal and low-lying regions (e.g., Bangladesh, Southern Florida, Netherlands)? (3.p5) With 6 meters of sea level rise, will most of New York City be submerged? (3.p7) What will be human loss in the coastal regions that are even not inundated by higher sea level? (3.p8) How does global warming affect air pollution? Why? (3.p39)

Low lying regions - rising sea level/increasing tropical cyclone New York will be submerged by 6m of sea level rise Human loss= dead or wounded Coastal regions not yet inundated (flooded) will be subjected to: Increased exposure to floods and storm damage More intense coastal surges Altered patterns of coastal erosion Air pollution= warming accelerates ozone production and promotes air stagnation

What are required to achieve lower stabilization targets? (2B.p43). To stabilize CO2 level at 450, 550, 750 ppm, by which year we need to reach emission peak? (2B.p42-43)

Lower stabilization targets requires sharp reduction in CO2 emissions. Sharp reduction in Co2 emissions following the 2040 peak (RCP 2.6) To stabilize CO2 levels at 450 ppm, must peak by 2020 (RCP 4.5) To stabilize CO2 levels at 550 ppm, must peak by 2040 (RCP 6.0) To stabilize CO2 levels at 750 ppm, must peak by 2080

What are the main reservoirs of carbon and processes of carbon transfer in the carbon cycle? Is photosynthesis important? Respiration? Does all of our CO2 emission stay in the atmosphere? If not, where does it go?

Main reservoirs of carbon: atmosphere, ocean, vegetation, soils, & detritus on land. Photosynthesis- red and blue boxes clicker question = respiration/photosynthesis. Respiration into atmosphere / photosynthesis into vegetation ½ of CO2 emissions stay in atmosphere, the other half sinks in the ocean

What are MPAs? Are they effective at reducing fish and coral loss? (3.p20) Can they protect coral from global warming? Ocean acidification? If not, then what needs to be done? (3.p21)

Marine Protected Areas(MPA's) have proven effective at saving off coral and fish losses, and are of great economic benefit. MPAs cannot protect coral from global warming, nor can they protect from acidification effects of CO2. What can be done to prevent this catastrophe is to reduce or eliminate CO2 emissions, or to sequester (hide) it before it escapes into the atmosphere.

does IPCC overstate the effects of climate change?

Over the past decade, due to natural factors, the globe has warmed a bit less than the model projected (the temperature changes were projected purely from future increases in greenhouse gases, without taking into account the timing of El Niño events, volcanic eruptions, and other natural factors that influence global temperature). Critics sometimes accuse the IPCC of overstating the effects of climate change.If anything, the opposite appears to be true.

How is precipitation projected to change? Why?

Precipitation pattern changes projected to occur by 2100 are in response to business-per-usual emission scenarios (RCP 8.5) Increased precipitation near the equator, polar, and subpolar regions Decreased precipitations in subtropics and mid-latitude regions (making them drier)

Under RCP8.5, how much warming does IPCC project by 2100? Under RCP2.6?

RCP 8.5: Warming of 2.5-4.6 C degrees (about 3.8-6.8 C degrees relative to pre-industrial time) RCP 2.6: Warming of 0.2-1.8 C degrees (about 1.2-2.8 C degrees relative to pre-industrial time)

Is the surface warming spatially uniform? What are the warming patterns and reasons? (2B.p8) Which continent will see the most warming? (2B.p9)

Surfacing warming is not spatially uniform Greatest warming over polar latitudes in northern hem due to positive feedbacks of melting ice Weak north atlantic warming due to change in ocean currents North America will see the most warming

What are the projected change of Arctic sea ice? (3.p61) The impacts (polar bear, international implications, etc)? (3.p42) What is permafrost? How is it expected to change in a warmer world? What are some of the impacts of permafrost melting? (3.p 64-65)

The Arctic Ocean will be ice-free in september later this century and the smallest projection is a 43% decline in year-round sea ice cover. Internal implications include the "middle of the road" scenario where North America and Eurasia will suddenly have to defend the Northern Coastlines. Permafrost - Permanently frozen soil. Permafrost is melting which will cause bridges to collapse, pipeline breakage, roadway degradation, and will ultimately release more methane into the atmosphere when it was originally trapped in the ice (causing increased warming).

How well did the past IPCC projection do?

The past IPCC projections compared well with what actually happened in subsequent years.

What are positive feedbacks associated with the carbon cycle? Negative feedbacks? Which type of feedback dominates? What does this imply for future climate change?

Warmer land -Positive feedback: Soil microorganisms increase their growth and respiration rates as their environment warms. One of the waste products of their metabolism is CO2. As a result, carbon in soils is now being converted to Co2 at increasing rates Negative feedback: This release of Co2 to the atmosphere by soil microorganisms offsets gains made by plants responding favorably in their growth to elevated Co2 levels. Warmer Ocean Positive feedback: A warmer ocean has less ability to absorb carbon dioxide, just as an opened can of warm soft drink loses its carbonation and goes flat. Ocean Acidification Negative feedback: Acidification of the surface ocean reduces the production of calcium carbonate by organisms such as corals and tiny plankton. Calcification reduces the ocean's ability to take up fossil fuel Co2. -Implies that warming is reducing nature's ability to absorb CO2 7 types = 4 ocean feedbacks 2 land based feedbacks 1 chemical weathering(Rock weathering)

what do fossil fuel emissions scenarios consider?

consider population growth,per capital enegery demand, economic growth and technological advances

Ice sheets during the last glacial maximum ?

covered most of Canada, Northern US, Scandinavia and Northern Europse; the ice sheets accounted for half of the cooling since they reflected heat rather than abosring it

what caused the "Faux Pause?"

explanation appears to lie with natural factors: background volcanic activity short term reduction in solar output series of La Nina events - all of which have let to Temporary surface cooling

climate model examples

explosive volcanic eruptions can be determines by the aerosol deposits they leave behind in ice cores GHG concentrations can be inferred from trapped air bubbles within ice cores

How does climate change stress human societies [e.g., natural resources (3.p41), fresh water supplies (3.p32), water pollution (3.p34), food supplies (3.p47), human health (3.p 51-52), international conflict (3.p45)]? What will happen when nations exceed their capacity to adapt to climate change? (3.p45) How might climate change affect environmental refugees? Why? (3.p43-44)

human societies= increase competition for natural resource Water supplies= diminished/unreliable fresh water supplies Water pollution= warmer water, more rainfall, longer period of low river levels will lead to more water pollution. Food supplies= increase with modest warming (1-2C) human health= spread of diseases (malaria) International conflict= stress water, land, food resources- lead to conflicts within/between nations and cause violence and destabilization of nations

Atmospheric fingerprints

increasing solar output warms essentially the entire atmosphere Volcanoes slightly COOL the TROPOsphere and WARM the STRATOsphere GHGs WARM the TROPOsphere and COOL the STRATOsphere

earths orbit configuration during the last glacial maximum?

summer sunlight at high northern latitudes was reduced snow from winter survives and more ice accumulates

climate model examples

sun spots: more sunspots=brighter sun;less sunspots= simmer sun

how are sunspots related to solar intensity?

sunspots record are available from early 17th century till today. more sunspots deliver more energy to the atmosphere, so that global temperature should rise. more sunspots=brighter sun less sunspots= dimmer sun

How was the Last Glacial Maximum (LGM) different than today?

temperature:3-8c cooler than today CO2: content is 50% less of what it is today Methane: was about 1/5 of what it is today Nitrous Oxide: was about 2/3 of what it is today

Why are fingerprints useful?

they help identify the likely underlying factor associated with that change. Spatial pattern of observed surface warming, and vertical structure of atmospheric temperature change point to the importance of human activities (GHGs)

why are future projections of climate change uncertain?

two factors: unknown trajectory of future GHG emissions uncertain response of the climate to these emissions

what is meant by climate change uncertainty?

uncertainty: the lack of exact knowledge, regardless of why this knowledge deficiency exists, and scientist try to draw conclusions through best guess scenarios of fossil fuel burning, and average projections of climate change

are there more sunspots than those in the Little Ice Age?

yes there are more sunspots than in the Ice Age Era