Global Climate Change Final Exam

T or F although there was a unusual amount of sea ice in 2012 the melt in the following years was back to normal

False

T or F increase in low cloud from global warming is a positive feedback

False

Where do you think the ice-albedo feedback is most important for changing annual surface temperatures? greenland brazil germany

greenland

the actual increase in greenhouse gas effect due to elevted CO2 concentrations is relatively small but this small push can be amplified by the earths climate system (2-4 times)

t

ice cores paleo

when air temp increases, more heavy water is evaporated measure isotopes in ice, and get a proxy for air temp

Impacts of climate change

- extreme weather - rising sea levels - coral bleaching - loss of biodiversity - air pollution

Radiative forcings

-Carbon dioxide largest -methane large too -aerosols (sulfer dioxide) can cool

Climate predictions

1- c02 emissions policy and econ 2- co2 concentrations carbon cycle 3- predict climate (global climate models/ forcings and feedbacks 4- impacts humans/environment

If an object's temperature doubles, it will emit how many more times radiation, according to the Stefan-Boltzman law?

16

which of the following is incorrect? 1- at the end of an ice age, carbon dioxide concentrations increase which increases air temperatures due to the greenhouse gas effect. 2- increases in solar radiation at high latitudes due to orbital variation trigger ice sheet melting 3- the increase in global temperatures at the end of an ice age is seen in ice cores records but not sea core records

3- the increase in global temperatures at the end of an ice age is seen in ice cores records but not sea core records

More low clouds suddenly appear. Where would these low clouds have the biggest impact on surface temperatures? greenland brazil

Brazil

Land use changes

Humans' effects on the climate system through modifications of the land surface e.g. through deforestation and agriculture.

Albedo

Reflectivity. Snow, ice, clouds and other bright surfaces have a high albedo, which leads to most sunlight being reflected to space. Ocean and vegetation on land have low albedos. They absorb lots of the suns radiation, which leads to warming.

Forcing

Radiative forcing (ΔF) is a change in energy fluxes F (in W/m2) at the top-of-the-atmosphere that causes climate change. It is defined as positive (negative) if it leads to warming (cooling). The radiative forcing for a doubling of CO2 is ΔF2xCO2 = 3.7 W/m2. Other examples are increased solar radiation (positive), increased aerosols (negative) or increased surface albedo (negative), e.g. due to land use changes.

Aerosols

Small particles in the air. Aerosols reflect sunlight back to space and therefore lead to cooling of the surface (negative forcing). Aerosols originate from natural (dust, ash from volcanic eruptions, wave breaking) and anthropogenic (smoke) sources.

select the following response lifteimes ranked correctly from shortest to longes methane-soot-carbon dioxide soot-methane- carbon dioxide carbon dioxide- methane-soot carbon dioxide-soot-methane

Soot-methane-carbon dioxide

All atmospheric gases -transmit -visible radiation while greenhouse gases -absorb- infrared radiation

True

Which type of radiation has the most energy?

Ultraviolet light

solar radiation (short wave)

Visible light Uv light Infrared

Which of the following systems exhibits a negative feedback? interest charges on your credit card? A building heating system? A ball perched on top of a hill?

a buildings heating system

wildfires

climate change in the western US has been linked to increased wildfire frequency urban encroachment on forests also leads to increases in forest fire suppression over time fuel builds up and leads to catastrophic wildfires

forcing

a change in energy fluxes F (in W/m2) at the top-of-the-atmosphere that causes climate change. It is defined as positive (negative) if it leads to warming (cooling). The radiative forcing for a doubling of CO2 is ΔF2xCO2 = 3.7 W/m2. Other examples are increased solar radiation (positive), increased aerosols (negative) or increased surface albedo (negative), e.g. due to land use changes. -initial shove causes a change in the system (for global warming it's the direct increase in the GE by co2) -increase in greenhouse effect due to increase in co2 is small, but the small push is amplified by earth climate system

heatwaves

adapting 2-4 c increase in air temp may be possible much more difficult to adapt to extreme temps

air pollution

air pollution increases wth elevated temps more energy demands means more pollution sources higher temps lead to faster pollution production

longwave radiation

all electromagnetic radiation from the earth less intense energy infrared

shortwave radiation

all electromagnetic radiation from the sun high energy

Thermal Equilibrium

amount of energy absorbed= the amount of energy released or radiated away -if the input of energy exceeds the output energy is added to the system and it will heat up - if the input of energy is less than the output energy is removed from the system and it will cool down - TE implies that there is no net heating of the system

positive feedback

amplify the push (lead to stability) bad to climate change

CO2 lifetime

at least 1000 of years for co2 to be completely removed

how do soot emissions warm the environment? a- they reflect short wave radiation b- they absorb long wave radiation c- they decrease the albedo of snow b and c a and c

b and c

Blue light has more energy than red light

because blue light is closer to ultraviolet and shorter wavelength IR radiation is less intense than visible light

extreme weather

climate is defined as the avg over 30 years to really understand if extreme weather is changing need long term records worst case scenarios melting ice caps arctic methane release sea level rise collapse of amazonian rainforest

Ocean feedback- thermohaline circulation negative feedback

co2 increases- increases in surface temp- ocean temp increases- glaciers melt- ocean becomes more stable (salt water more salt the denser it is if you melt more ice it makes it fresh water which makes it stable- no deep water formation (instead of water form surface sinking to the deep that process slows down- gulf stream changes course- temp in europe decreases

Ice albedo feedback (positive feedback)

co2 increases- surface temperature increases through th egg effect- glaciers start to melt (they have high albedo) - when they melt it it makes the labedo go down- the solar absorption increases (amount of sunlight absorbing increases)

cloud feedback 1 (postive feedback)

co2 increases- surface temperatures increases- increased evaporations- more clouds- high clouds- causes long wave radiation to be trapped by atmosphere - long waves reradiates back to the surface of the earth- leads to increase in surface temp

cloud feedback 2 (negative feedback)

co2 increases- surface temperatures increases- increased evaporations- more clouds- low clouds- increases earth albedo-it cools it off because it reflects more sunlight and that causes the surface temp to decrease-

Stefan-Boltzmann Law

computes the total flux of energy emitted per unit area as a function of temperature

Wein's law

computes the wavelength of the most intense radiation as a function of temperature

Negative feedback

diminish the push (lead to stability) in climate change they are good

agriculture and food supply

drought and extreme temps are detrimental to food production some northern regions may become more productive key is variability (developing countries have little cushion/ cities depend on surrounding regions for food production

geothermal energy and nuclear energy

energies that do not come from the sun

drought

even if no change precipitation, warmer temps mean less storage as snow in the sierra nevada mountain range- snow acts as a natural reservoir to provide a steady flow of water

tree rings

find a location where trees are growing in a cold environment during warmer years trees grow more (rings are bigger) many cold env are dry, so can also get records from deadwood calibrate with air temp records from thermometers can go back 1000 years longer with less reliability

energy issues

food supply- cities outside look for energy supply cities can be energy efficient (public transportation/ heating and cooling ) concentrated pollution cities are more vulnerable to energy disruptions they also have unique opportunities for conserving energy cities have lower emissions

The impact of aerosls on climate is ------- and the impact of the melting sheets is a forcing/forcing forcing/ feedback feedback/forcing feedback/feedback

forcing/feedback

which combination produces the smallest future emissions ? global econ regional econ global env regional env

global /environment

which combination prodces the largest future emissions ? global econ regional econ global env regional env

global economic

forcings carbon dioxide is the largest methane is large too aerosols (soot dust) can cool

t

extreme weather

hard to pin a single extreme weather event on climate change one approach is to say how much more an event is under climate change can say that some extreme events are consistent with climate change science of attributing extreme events to climate change is progressing EPA best source of info about hwo climate is changing (not up to date )

which of the following is most worrisome for chicago? heatwaves sea level rise landslides drought food supply

heatwaves

feedback

how a system responds to a focing

Climate Feedback

how a system responds to a forcing -A change in the climate system as a response to a radiative forcing that will amplify (positive feedback) or dampen (negative feedback) the initial forcing. E.g. initial forcing of increasing CO2 leads to warming, which leads to more evaporation and water vapor in the air, which leads to more warming (because water vapor is a greenhouse gas). Important feedbacks are the Planck (negative), water vapor (positive), ice-albedo (positive), lapse rate (negative) and cloud (positive or negative) feedback. The sum of all feedbacks determines the climate sensitivity.

flooding and landslides

increased extremes in precipitation lead to more intense floods and landlsides in developing countries landlsides often impact poor that build on marginal sites

aerosols

liquid and solid particles that remain suspended in the atmosphere (not gases) examples- volcanic dust dust soot from cooking, fires, combustion and engines aerosols forcing aerosols increase- increases albedo (more sunlight reflected)- less short wave radiation absorbed- less surface temp other way aerosols can work aerosols increase - absorb shortwave radiation in atmosphere-increases temp of earth atmosphere- reradiates long wave radiation back to surface - which causes increase in surface temp

sources of methane

livestock manure rice paddies wastewater treatment plants municipal waste, coal mines, gas transmissions, oil and gas production

sea core

look at oxygen isotope imbedded in organisms that live on the sea floor when it is cold more heavy water is left behind gives and estimate of global ice volume

disease-- human and plant

malaria and west nile (born by mosquitoes) climate extremes are the culprit- drought followed by rains spread of malaria zones warmer temps - more mosquitoes zika virus

Hurricanes

may become more intense medium level of certainty

greenhouse gases

molecules that are able to absorb and emit electromagnetic radiation in the infrared part of the spectrum (longwave). Water vapor (H2O), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are Earth's most important greenhouse gases.

soot (aka black carbon)

more prevalent in developing countries india and southeast asia warming is more regional-glacial met

ice age

more than 30 glaciations over 2-3 million years at intervals of about 90,000 years currently in an interglacial period- its warm whats the cause? variations in the earths orbit around the sun

Water vapor feedback (positive feedback)

most important feedback 1- co2 increases 2-increased greenhouse effect causes the earths surface to warm 3-the warming evaporates more water vapor 4- increased water vapor leads to an increased greenhouse effect CO2 increases-causes surface temperature to increase (initial shove)- evaporation increases-amount of h2o in atmosphere increases- more long wave radiation trapped in the atmosphere- long wave radiation gets trapped behind the increased # of water vapor molecules reradiate that long wave radiation back into the surface (counter radiation)

sea level rise

most well known and dramatic consequence of global warming rising temps lead to melting ice sheets and thermal expansion of ocean Vulnerability to sea level rise is a combo of physical changes and social factors (level of development leads to more resources)

low thick clouds

negative feedback high albedo cool small greenhouse effect

which location gas the least paleo climate data? north america europe south america africa

north america and europe have a lot more africa one south america 2 but both are correct

list some potential abrupt climate changes that have occured with other env issues

ozone hole cfc destroy the layer but the whole in the ozone layer is very abrupt and not clear

If the Earth cools, less water vapor is evaporated, and the Earth cools some more, this is an example of a _______________ feedback.

positive

high thin clouds

positive feedback warm (don't change earth albedo much increase in greenhouse gas effect

methane

strong greenhouse gas more potent than co2 (more warming than co2 per molecule )but has a shorter lifetime reactive gas about 5% remains after 30 years

Paleoclimate

study of past climates old adage- the key to understanding the future is understanding what we know about past climates

Fracking

the bad natural gas from fracking increased 500% over 5 years coal use for electricity production dropped 15% during that time this decrease compensated by increases in natural gas and renewable energy fracking can release methane that is not captured methane leaks in distribution offsets efforts to reduce short lived gases the good burning natural gas produces 1/2 the co2 compared to coal little toxic air pollution (co- benefit) natural gas not too bad (improves air quality) reduces our carbon dioxide emissions

forcing

the initial shove that causes a change in the system for global warming this is the direct increase in the greenhouse effect caused by CO2 (lead to feedbacks - forcing initial shove feedback response to initial shove

Weather

the instantaneous state of the atmosphere around us. It consists of short-term variations over minutes to days of variables such as temperature, precipitation, humidity, air pressure, cloudiness, radiation, wind, and visibility.

Climate

the statistics of weather over a longer period. It can be thought of as the average weather that varies slowly over periods of months, or longer. It does, however, also include other statistics such as probabilities or frequencies of extreme events. Climate is potentially predictable if the forcing is known because Earth's average temperature is controlled by energy conservation. For climate, not only the state of the atmosphere is important but also that of the ocean, ice, land surface, and biosphere.

which of the following is true? climate change will reduce crop yields all over the globe increasing co2 concentrations always increase crop yields changes in the mean amount of precipitation are most important for agriculture there is uncertainty about climate change and future yields

there is uncertainty about climate change and future yields

all objects emit radiation

true

greenhouse gas concentration paleo

usually from ice records measure concentrations of gases that get trapped in air bubbles within the ice question of dating is an issue can use isotopes from same ice core to estimate air temp c02 and temp are tightly correlated both co2 and air temo increase dramatically at the end of the ice age

global warming focings

water vapor ice albedo clouds ocean circulation