Chapter 16 Global Climate Change
all models show a 2°C to 5°C rise in world temperature and a 1ft to 3ft rise in world sea level by the year? orbital forcing applied to Earth definition
2100 changes in either Earth's axis of rotation or its orbit in relation to other celestial bodies that affects the Earth's climate; climate effects of Milankovitch cycles
-non-dimensional, unitless quantity that indicates how well a surface reflects solar energy -commonly refers to the "whiteness" of a surface, with 0 meaning black and 1 meaning white what do the statements describe? most life on Earth has evolved to see what EMR?
albedo *measure of the diffuse reflection of solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that reflects all incident radiation visible light
when you feel heat outside, the heat felt is from the atmosphere or the Sun, and why? *think is the heat being felt from the air or the ground, a hint... this explains daily temperature changes number of sunspots on Sun is directly related to what?
atmosphere because a small amount of visible light is absorbed by the atmosphere and gets energized, releasing reradiated infrared light *rest is absorbed by surface solar energy output
water vapor is a greenhouse gas that helps warm the atmosphere by trapping some of the radiation Earth emits into space—this explains why it tends to be warmer on cloudy nights compared to clear nights but clouds also have a___ effect in general on the climate by reflecting incoming sunlight (reflection beats radiation trapping) but... lower-level clouds are expected to have a net cooling effect, whereas upper-level clouds should help warm the atmosphere, maybe
cooling
from 1000 to 1850's global climate was? hint:mini ice age from 1850 to today global climate has been? it has been confirmed that solar output has increased from 1610 to the mid-1900's and this is associated with more solar energy in the form of EMR reaching Earth has this been enough to explain the unusually fast period of global warming that we are experiencing?
cooling warming and doing so unnaturally fast no
has the Earth been warming or cooling during the last 150 million years—considering more geologic time? above what temperature in Fahrenheit and Celsius does liquid water thermal expand? orbital forcing
cooling (just been warming fast the last 150 years give or take but it is really minor compared to other much warmer periods within the last 500 million years) 40 degrees F or 4 degrees C
significant and rapid rise in the average global temperature opposite of above is? global climate change a scientific body created by the United Nations in 1990 that summarizes the research results on climate change from scientific institutions around
global warming global cooling wide variety of changes in Earth's climate system Intergovernmental Panel on Climate Change (IPCC)
absorbing energy causes Earth's surface to heat up Earth's surface gives off longer wavelength infrared light gases in atmosphere absorb the IR emitted by the surface of the Earth (greenhouse gases) absorbed IR keeps the atmosphere 60 degrees F warmer than it should be what is this?
greenhouse effect
what is responsible for the current global warming affecting Earth? why is the modern rate of fossil fuel emission so problematic for the world climate? is the current global warming and successive climate change natural, anthropogenic, both, or neither, in this course?
more greenhouse gases being released into the atmosphere, mainly from fossil fuels that release CO2 from the geosphere to the atmosphere ever since the Industrial Revolution excess CO2 emitted into atmosphere cannot be absorbed or contained in other reservoirs; too much in short amount of geologic time anthropogenic (it can be argued human assisted but more evidence is saying purely by man)
the contribution of individual gases to the greenhouse effect depends on their molecular properties, concentration, and residence time in the atmosphere __will absorb and transfer about 30 times more energy to the atmosphere than carbon dioxide, which is considered the most important anthropogenic greenhouse gas because of its higher concentration and long residence time (about 100 years for CO2 and NO2, and only 10 years for CH4)
methane CH4
why is anthropogenic CO2 emissions more problematic than natural processes that does the same?
natural processes emits more CO2 than fossil fuel burning, but they also remove lots of naturally emitted CO2, which is not the case for fossil fuel burning ex: 1.vegetation removes CO2 2.CO2 gets dissolved into oceans 3.precipitation of carbonate minerals meanwhile, anthropogenic emission is not removed as much, so issue is net gains, not total emissions, and natural removal is relatively slow and constantly pretty much
-after El Niño, the trade winds are sometimes stronger than usual as they push the warm water westward again -enhanced movement of air and water allows cold water from higher latitudes to move down farther than usual into the equatorial Pacific -as cold water pushes into the eastern Pacific, it suppresses rainfall in the western United States and alters the course of the upper-level air currents (jet stream) -before ESO stabilization (3-5 months) what is this?
La Niña
-this circulation within the oceans is driven by winds and by the temperature and density differences of the water -collection of large-scale density- and wind-driven currents that move in a convective manner through the ocean basins -it transports heat from the tropics to the polar regions and also distributes freshwater around the planet what is this? important ocean phenomenon that affects global weather patterns is the periodic changes in water and air currents in the equatorial, eastern parts of which ocean?
thermohaline circulation Pacific
because sea ice floats on the ocean, this melting will not lead to sea-level___rise/fall/neither___ methane has a residence time in the atmosphere of about a decade, and once in the atmosphere, it converts to carbon dioxide, whose residence time is around___years in addition to methane gas hydrates, the polar regions also have? these are thick layers of saturated organic material, known as peat that have been sequestering carbon in the cold climate, and when they begin to warm, the carbon breaks down and is converted into methane
neither 100 bogs
the Sun and stars similar to it emit radio waves through X-rays on the electromagnetic spectrum (EMS) does the Sun emit gamma-rays? in Earth's atmosphere, most high energy electromagnetic radiation (EMR) is blocked by the___and most low energy is blocked by___ ___is mostly not blocked and reaches the surface Earth primarily emits___and most of this is captured within the atmosphere thanks to water vapor but a small quantity escapes into outer space
no ozone layer; water vapor visible light infrared light
most promising alternative energy sources considering our future there is growing evidence that air pollution from___is also affecting the climate by cooling it, though it is being overpowered by the warming effect
1.solar 2.wind 3.nuclear *nuclear power can provide large quantities of reliable base-load electricity to the grid, with solar and wind working in tandem to help meet peak demand + wind and solar are already less expensive means of producing electricity than coal-fired power plants, plus they do not have all the environmental costs associated with using coal, oil, and natural gas aerosols
name 5 greenhouse gases data sources that can be used to estimate past temperatures
1.carbon dioxide 2.water vapor 3.methane 4.nitrous oxide N20 5.hydrofluorocarbons and other fluorinated gases; ok more than 5 temperature proxies
some more strategies for reducing greenhouse gas emissions it should should be noted that large quantities of carbon can also be sequestrated in forests and soils, and while this could help remove excess carbon dioxide from the atmosphere, it is not a long-term solution because?
1.energy conservation 2.increased energy efficiency 3.incentives ex:carbon tax; cap and trade; bargaining relatively short life-cycle of carbon in trees and soils
evidence that Earth's climate has warmed over the last 150 years or so and why? alternate theories to climate change that were debunked
1.global sea level has risen 8 inches over last 150 years 2.melting alpine glaciers, polar ice caps, and ice sheets worldwide 3.thermal expansion in oceans causing oceans to warm and to lose sea ice; melting sea ice 4.thermometers worldwide have recorded more years warmer than global mean temperature since 20th Century 1.net size of ocean basins have shrunk: faster seafloor spreading will bulge up mid-ocean ridges and bulging ridges take up more volume, less room for ocean water, so sea levels rise 2.ocean basin near Arctic has widened Arctic Ocean freezes during winter; if area between Greenland and Europe has widened because of seafloor spreading, more Gulf Stream water can get to Arctic Ocean, thus warming the water and resulting in less sea ice *neither occurring fast enough
plants thrive when CO2 collects so why is more CO2 in the air bad? utilizing of what represents millions of years of accumulated and stored carbon?
1.increasing CO2 levels exceeds rate of new plant growth plus plants only grow & proliferate at rates that are too slow to remove the excess CO2 from fossil fuel burning 2.replacement of natural forests and grasslands by agriculture is a net loss of stored carbon in plants—deforestation is a net loss since rain forests & grasslands store more carbon than farmlands 3.warmer climate from CO2 rise in atmosphere will increase desertification; forests to grasslands to deserts more; net loss of plants exceeds removal of CO2 via stimulated plant growth fossil fuels
consequences of a 3° to 5°C temperature increase across the world by 2100
1.more shrinking cryosphere results in 1-3ft rise in global sea level and more flooding 2.changing weather patterns-more droughts in some areas and more rainfall & floods in others, and also more other precipitation in yet other areas *bonus:not necessarily more storms but will be more intense and unpredictable 3.more acidic oceans via more CO2 absorption and reaction with H20 that makes carbonic acid H2CO3; less calcium carbonate CaCo3 as coral reefs and sea shells are lost from acidification *applies for other greenhouse gases too like CH4 4.mass extinction as many species won't be able to adjust 5.changes in agricultural patterns 6.movement of climate zones and biomes towards poles 7.spread of tropical diseases towards the poles
rough Earth atmospheric composition in descending order in %
1.nitrogen-78% 2.oxygen-21% 3.argon-0.93% *everything else is in trace amounts including greenhouse gases
global rankings of energy sources used (2006) name organisms that are particularly sensitive to pollution and climate change? what can be done about anthropogenic global warming?
1.oil 2.coal 3.natural gas 4.biomass 5.hydropower 6.nuclear 7.geothermal 8.all others amphibians decrease or stop fossil fuel extraction and emission with the help of taxation, bargaining, tradable permits, or banning?
Earth climate zone categories the oceans store 93.4% of all of Earth's heat and without them the___—the 2nd largest storage-would would be 10°C warmer
1.tropical-tropical wet; tropical wet and dry 2.dry-semiarid; arid 3.moderate-humid subtropical; marine west coast; Mediterranean 4.continental-humid continental; subarctic 5.polar-tundra; polar; highland 6.non-permanent ice atmosphere
which has global warming warmed the most? A.oceans B.atmosphere C.continents D.glaciers and ice caps E.sea ice F.ice sheets G.all what is used to get an idea what climate was like in the past (get temperature proxies)?
A.oceans 1.historical records from humans 2.trees: tree rings from across globe used to reconstruct global climate conditions over last 5,000-10,000 years; thick tree rings = warm + wet; thin tree rings = cool + dry 3.pollen: oak + grass = warm and wet spruce + pine trees = cool + dry 4.oxygen isotopes: track 2 isotopes 1.oxygen-16 (16O): 8 protons & 8 neutrons; atomic mass of 16 2.oxygen 18 (18O): 8 protons & 10 neutrons; atomic mass of 18 18O/16O ratio determines ocean temperature because ocean water has more 180 and ice has more 160, plus sea shells store the same amount of both isotopes if oceans have more than usual 18O, then global warming and the opposite for global cooling (more than usual 16O) *it should be alternating as 160 is evaporated from and oceans and returned from stream discharge **during ice ages, oceans have depleted 160 that is stored in expanded glaciers, ice caps, ice sheets, and sea ice, and has elevated 180 concentration ***tracked using glacial ice and seashell compositions and radiometric dating to determine age 4.thermometers worldwide have recorded more years warmer than global mean temperature since 20th Century 5.glacial features; less pronounce due to melting 6.fossil record provided by sedimentary rocks
David Keeling measured global CO2 levels and already suspected that CO2 levels drop in spring & summer and rise in fall & winter annually what Keeling didn't expect? *leaves mature during the spring and summer, and die and decomposes in the fall and winter
CO2 levels were consistently rising over the years, decades, and centuries
what climate program is this that never took off? -part of the U.S. strategy of the Paris Climate Agreement -under this new program, the EPA set emission standards for electric generating plants that burn fossil fuels -set the goal of having renewables, primarily wind and solar, supply 28% of U.S. electricity by 2030—renewables currently provide about 15% of U.S. electrical production -never went into effect as opponents immediately challenged the program in U.S. federal courts evidence from Greenland ice suggests that the current ice covering of the Earth began___ago rather than around 3 million years ago
Clean Power Program around 8 million years
what climate agreement is this? -in 2010, representatives from nations around the world met in Copenhagen, Denmark, and agreed to reduce their CO2 emissions by 2020 -non-binding plus the agreement did not extend the binding caps previously agreed to under the 1997 Kyoto Protocol.
Copenhagen Accord
-divided into sets of three large-scale atmospheric circulation "cells" in the Northern Hemisphere + Southern Hemisphere that shift polewards in warmer periods and towards the equator in colder periods -irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics, and much of the world really -has accompanying atmospheric component, coupled with the sea temperature change -included El Niño and La Niña
El Niño-Southern Oscillation (ESO)
energy Earth receives from the Sun = energy Earth radiates into space 50% is absorbed, reflected, or scattered by clouds (most high energy and low energy of EMS) 50% is absorbed by Earth's surface (most VL) what is this? absorbed heat keeps the atmosphere how much warmer than it should be in F? to be more precise, heat or thermal energy results from what?
Earth's energy balance 60 degrees F mid-infrared light
-periodically disrupted when easterly trade winds slacken along the equator, allowing the elevated pool of warm water to migrate eastward toward South America *easterlies are trade winds and westerlies are anti trade winds -produces dry conditions in Southeast Asia and Australia, brings heavy rains and destructive flooding to parts of coastal North and South America. -on the other side (facing away from ocean) of the Andes Mountains in South America, precipitation typically decreases over the Amazon rainforest -generally occurs every 3-5 years and lasts for 9-12 months, after which time the ocean and wind currents in the equatorial Pacific return to their normal pattern what is this?
El Nino
most famous part of the thermohaline circulation
Gulf Stream
what climate agreement is this? -first serious effort to reduce greenhouse gas emissions was this 1997 international treaty -developing nations were exempt from having to meet specific emission reductions; rationale behind the exemption was that most of the excess CO2 currently in the atmosphere was released over many decades by industrialized nations -developing nations would be able to first grow their economies, and then reduce emissions later -in 1998 the U.S. Senate failed to ratify largely because China was exempt from emission reductions due to its developing nation status
Kyoto Protocol
what climate agreement is this? -most recent attempt by the international community to cut greenhouse gas emissions occurred in 2015, when 196 nations signed -designed to reduce emissions to a level scientists believe will keep temperatures from rising beyond the IPCC's 2.0°C (3.6°F) target over preindustrial levels -no exemptions for developing countries and all participating nations are required to submit individual plans for reducing carbon emissions through 2030 -non-binding -since many climatologists believe that the climate system will pass critical thresholds earlier than previously expected, the deal set a long-term goal of keeping the temperature rise below 1.5°C (2.7°F) -each member nation is legally required to monitor and publicly report on its progress every five years and are legally required to meet every five years and submit updated plans that include even more stringent reduction
Paris Climate Agreement
the element___makes up a very small percentage of the entire Earth but has become concentrated near the surface because of biological activity and the planet's internal heat and plate tectonics if the Earth did not have mechanisms for removing CO2 from the atmosphere, then the outgassing by volcanoes over time would have led to an ever-intensifying___long ago partly because of the oceans' ability to absorb CO2, there must be something removing CO2 from the oceans and placing it in storage, otherwise the oceans would have become saturated and stopped absorbing additional CO2 early in Earth's history—carbon sequestration that occurs not only artificially but also naturally
carbon C runaway greenhouse
the key process that sequesters carbon dioxide from the ocean-atmosphere system is the formation of___sedimentary rock geologic processes in the carbon cycle operate on time scales covering millions of years, but there are biological and chemical processes within the cycle that affect greenhouse gas concentrations on time scales ranging from___ that largely affect short term global climate change in coastal cities, unusually high tides combined with higher sea levels have allowed seawater to move up through the stormwater system and cause street flooding, even on dry and clear days—commonly referred to as sunny day___
carbonated days to millennia floods
processes within the Earth system that respond to a disruption in the energy balance, and then act to either increase or decrease the energy imbalance positive climate feedbacks increases or amplifies the system's response to a change in the heat balance, whereas negative climate feedbacks works in the opposite sense and reduces or dampens the response give an example of each type of climate feedback
climate feedbacks positive-thawing permafrost releases additional greenhouse gases (CO2 and CH4), which then amplify existent global warming, and the thawing permafrost will actually result in another positive feedback as underlying methane gas hydrates located in polar regions thaw and release more CH4 negative-elevated CO2 levels cause plants to absorb CO2 at a higher rate, which then reduces or dampens the effect of global warming until they cannot keep up with emission rate
processes that disrupt Earth's energy balance, thereby forcing the climate to change give example ^
climate forcing (climate drivers) if the Earth were to suddenly gain heat due to a large asteroid impact, the amount of heat escaping into space would abruptly increase until the equilibrium of the energy balance is restored
to simulate Earth's global___, scientists use what are called general circulation models (GCMs), in which the simulation period is commonly on the order of years to decades results are statistical in nature and have a certain level of scientific uncertainty, which is a mathematical term expressing the___ groupings of similar organisms and are functions of temperature and precipitation patterns amount of energy stored in a given system or region of space per unit volume
climate or climate system likely range of results biomes energy density
glacial ice sheets are actually slow-moving bodies with numerous fractures called lakes often form on the surface of ice sheets during the summer, which increases solar heating and accelerates the melting, and this meltwater also moves downward through crevasses and large vertical conduits called___, causing the ice to melt from within some of this water will build up and this increases the pore pressure at the base of the ice, thereby reducing the friction between the glacier and underlying bedrock, and the reduced friction allows the ice to flow more rapidly, and in some cases, triggers a sudden and rapid increase in flow called a___ the combined effects of internal melting and glacial surging act as a positive feedback, which can cause large ice sheets to break up much more rapidly than predicted by previous model calculations glacial topography: narrow glacial valleys rapidly moving zones some ice streams extend great distances over the sea and form what is known as?
crevasses moulins glacial surge fjords ice streams ice shelfs
true or false, variation in sunspots has produced relatively large changes in our climate compared to those that have resulted from the modern increase in greenhouse gas concentrations? when sunlight strikes an object (matter), some of the light is transformed into thermal energy, a process called? *naturally warms our planet whenever sunlight strikes the atmosphere, land, or oceans energy balance also called?
false solar heating heat balance
despite solar output having increased somewhat over geologic time, Earth has still remained within the solar system's___-where surface temperatures allow liquid water to exist, and this has provided our planet with the ideal conditions for the evolution of complex life solar output or the electromagnetic radiation emitted from the Sun is formerly called and oscillates back and forth in a rhythmic manner as it rises overall during the Sun's lifetime up until a certain point the oscillating cycles are linked to? the number of sunspots on Sol (the Sun) varies on an 11-year cycle, with more sunspots corresponding to higher___
habitable zone solar irradiance sunspot activity (relatively cool, dark areas on the Sun's surface) the number solar irradiance (output)
what is included for high energy electromagnetic radiation (EMR)? medium energy? low energy?
high: 1.gamma-rays 2.x-rays 3.ultraviolet light (UV or UVL) medium: 1.visible light (VL or light) low: 1.infrared light (IR, IRL, or heat) 2.microwaves 3.radio waves 4.extremely long frequencies (ELF) *basic a bit
fast flowing, narrow, meandering, air currents in the atmospheres of some planets, including Earth why does the oceans together (most of the hydrosphere) store over 90% more heat (mid-infrared light) than the 2nd largest storer, the atmosphere
jet stream water has a much higher heat capacity than air, meaning the oceans can absorb larger amounts of heat energy with only a slight increase in temperature
will global warming eventually result in a water world scenario or end all life? *or not within next 500,000 years? explain carbon capture and sequestration and the related pros and cons
no and no process: 1.after burning fossil fuels and using scrubbers to decrease pollution as they are emitted—most likely conventional—; CO2 is captured and compressed 2.compressed CO2 is decompressed (liquefied) injected and pumped into ground (sequestered), in permeable rock or sediment layers *maybe depleted confined aquifer too **refining is only part that can be done elsewhere pros: 1.no greenhouse gases emitted based on net cons: 1.must burn fossil fuels at same locations that petroleum (oil and natural gas) is pumped out, processed, and maybe refined 2.CO2 could decompress and leak out over time due to leakage even though it will be slow and more beneficial to do it 3.aligns with oil and natural gas extraction but doesn't align with coal mining 4.expensive
is orbital forcing from than Malintovich cycles responsible for the current warming trend of Earth's climate and why or why not? Malintovich cycles what is precession in astronomy or general precession?
no, although the cycles do affect the distribution of solar energy (solar radiation) reaching Earth, they are only significant over tens to hundreds of thousands of years, not within the last 150 or so years 1.eccentricity (orbital eccentricity)-variation in Earth's orbit from near circular to slightly elliptical more circular-less seasonal difference in solar energy distribution during summer and winter more elliptical-more seasonal difference in solar energy distribution during summer and winter; more extreme seasons 2.obliquity (axial tilt)-variation in the tilt of the Earth's axis of rotation from 22.1 degrees to 24.5 degrees closer to 22.1-warmer winter in Northern Hemisphere and cooler summer in Southern Hemisphere and the reverse closer to 24.5-cooler winter in Northern Hemisphere and warmer summer in Southern Hemisphere and the reverse 3.axial precession (planetary science)-variation in the orientation of Earth's axis of rotation from closer to the Sun to further leaning more towards the Sun-warmer leaning more away from the Sun-cooler 4.apsidal precession-variation in the rotation direction of Earth's orbit 5.orbital inclination (planetary precession or precession of the elliptical)-variation in the inclination of Earth's orbit from up to down variation in the orientation of the rotational axis of a rotating body
study of Earth's past climate change to make and edit the global climate record most climate recording goes only as far back as more or less 3 million years ago since_ 18 of the 19 hottest years on record have taken place since 2001, and the 4 hottest have occurred since? climate threshold
paleoclimatology only the most recent cycle of glacials and interglacials (the most recent ice age) began around 3 million years ago 2015 some component of the climate system is pushed beyond a critical point, causing the entire system to suddenly change; there are thought to be many
scientists have found evidence for a major global warming event 55 million years ago, which is believed to be related to a rapid release of carbon dioxide and methane from the___
seafloor likely from rupturing methane gas hydrates and flood basalt eruptions at spreading centers; lasted approximately 200,000 years, but the global average temperature increased as much as 11°F (6°C) in just the first 20,000 years
land temperatures on Earth are recorded from ground stations and ocean temperatures from satellite, buoys, and__ ___concentration is measured is in parts per million (ppm), whereas the CH4 and N2O concentrations are in parts per billion (ppb) primary driving force behind Earth's climate system? A.oceans B.radiation emitting from Earth's surface C.solar radiation coming from the Sun D.gas molecules in the sky E.all contribute equally
ships CO2 (carbon dioxide) C.solar radiation coming from the Sun
measurement of the speed of the gas molecules (gas kinetic energy) which oxygen isotope evaporates faster and is thus found less in ocean water and more in the air and precipitation, natural oxygen (oxygen-16) or oxygen-18? even though it has oxygen-16 and oxygen-18, ice collects less of which? *17 is radioactive so we ignore
temperature natural oxygen (oxygen-16) oxygen 18
since___changes temperature more slowly than air, the oceans end up storing some of this heat from the atmosphere each day, and the additional heat is later released back to the atmosphere whenever the air temperature becomes cooler than seawater *explains why water stores over 90% more heat than air because incoming___is more intense near the equator, tropical regions undergo considerably more solar heating and evaporation than do areas at higher latitudes *causes tremendous amounts of water and heat to be transferred from the tropical oceans to the atmosphere, and the combined energy imbalance combined with the rotation of the globe sets in motion wind and ocean currents that transport both energy and water to higher latitudes * density of water is determined by both its temperature and its?
water solar radiation salinity
short term local variations in temperature, humidity, precipitation, wind, atmospheric pressure, and cloud cover *weeks, days, and months same atmospheric conditions as weather, but over time periods of decades, centuries, or millennia climate pertains more to regions than locations, true or false? 1/2 of sea level rise is happening because of melting ice and 1/2 from
weather climate true warming oceans via thermal expansion
