global changes final
what is the keith group at harvard doing in the realm of stratospheric aerosols? are there implications of this?
aims to create whiter clouds in order to reflect more sunlight back to space. completes this by shooting sea salt aerosols into marine clouds -> cloud condensation nuclei->diminish solar radiation, therefore reducing temperature -implications include change of weather patterns
what is global warming potential?
atmosphere lifetime+heat potential usually given per 100 years referenced to CO2 which has a GWP of 1.0 and denoted as CO2-e
most of earth's land that is not covered by ice or desert is projected to undergo at least a ____% change in plant cover
30
How much has the surface waters of our oceans increased in acidity over the past 250 Years?
30%
what did the kyoto protocol require?
38 developed countries to cut their emissions of certain GHG's to 5.2% below their 1990 levels by the year 2012.
Approximately _______ people are assessed as currently subject to severe water scarcity for at least ______ per year due to climatic and non-climatic factors
4 billion, one month
coldwater fish are losing their habitat, with projections of ____% habitat loss by 2080
47
Approximately how many people in the US live within 4 ft of high tide?
5 million
assuming a future in which cities the size of Dallas, due to adaptation, could result in an approximate ____% reduction in extreme temperature mortality estimates.
50
a _____ meter increase in sea level would submerge about the bottom 1/3 of florida
6
projections are likely when they are ______%, and very likely when they are ______%. *percentages are ranges*
66-89; 90-99
if all the ice covering antarctica, greenland, and in mountain glaciers around the world were to melt, sea level would rise ____ meters.
70
____% of the costliest hurricanes in American history have occurred in the past 15 years.
90
IPCC scenarios: A vs B models
A models are more economically/business focused, and B models are focused more toward sustainability and environmental changes
how are the Adelie and Chinstrap affected by climate change in completely different ways?
Adelie penguin: inhabits the winter ice pack; populations have decreased by 22% in the last 25 years Chinstrap penguin: inhabits open water; populations increase by 400%
the national drought monitor, the colorado river basin governance, forest adaptation, and cape cod mitigation are all examples of _____ efforts.
adaptation
What is defined as the potential of a system to adjust to climate change?
adaptive capacity
The gas lifetime for nitrous oxide is
long (100 years or more)
The concept of Intergenerational Equity suggest that the future discount rate should be _____
low
what is geoengineering?
the deliberate large-scale intervention in the Earth's natural systems to counteract climate change
decoupling issue in snowshoe hare caused by climate change
the hares may shift their colors depending on the amount of sunlight available, not weather related
mitigation of global warming
"buying ourselves more time" -aims to reduce GHG emissions, which will slow climate change, which gives us more time to switch to renewable energy sources.
what is the DICE model?
"dynamic integrated climate economy" model -weighs the projected economic damages from global warming against costs of mitigation -used by EPA -run over 400 years, typically
The current rate of CO2 rising in the atmosphere is
3 ppm/year
Why is Antarctica's sea ice growing while the Arctic sea ice melts/shrinks in size?
-The Southern Ocean Circumpolar Current prevents warmer ocean water from reaching the Antarctic sea ice zone, helping to isolate the continent. -The winds within that ice zone keep the water extremely cold.
what is cloud seeding, and what event did we talk about in class?
-The scattering of chemicals into clouds to bring about rain. Dry ice/silver iodine is put into the clouds. -cloud seeding was done in North Dakota in 1972, and flooded the town.
what are the aspects of carbon capture?
-afforestation (engaging in global scale tree planting effort) -ambient air capture ( large machines that will remove CO2 directly from ambient air and store it elsewhere) -biochar (charring biomass and burying it so carbon is locked up in soil) -bio-energy (growing biomass, burning it to create energy and capturing the CO2 in the process) -ocean alkalinity enhancement (grinding up rocks in the ocean to increase its ability to store carbon and directly improve ocean acidification) -ocean fertilization (adding nutrients such as iron to the ocean to increase primary production which draws CO2 from atmosphere) -enhanced weathering (storing a reactive compound in the ocean or soil)
what is albedo enhancement?
-aspect of solar engineering -increasing the reflectiveness of clouds or the land surface so that more of the Sun's heat is reflected back into space -e.g space reflectors, aerosols
adaptation of global warming
-devises strategies to reduce inevitable harmful effects of GHG's.
what is the "coastal spine" of Texas, and what is happening to it?
-flooding of Highway 1, the gateway to many oil facilities, is increasing -18 feet annually lost to erosion -wetlands are disappearing
what are the three major strategies for carbon reduction?
-improve energy efficiency -shift from carbon-based fossil fuels to carbon-free renewables -sequester as much CO2 as possible in soil, vegetation, the underground, and the deep ocean
what practices can make a significant contribution to the removal of CO2 from the atmosphere at a relatively low cost?
-improved agricultural practices (better land management, more efficient fertilizer use can minimize soil erosion and increase restoration) -forest-related mitigation
why do economists like to place a lower value on consumption occurring in the future rather than in the present?
-improved technology of the future makes it easier to address global warming concerns -future consumption levels are uncertain -consumption levels will be higher in the future -because of inherent discounting, people prefer the present to the future
how can cities fight back against climate change?
-invest in cooling techniques (e.g green roofs, eventually to receive incentives for doing so) -embrace urban-growth with clean energy solutions(e.g solar panels, recycling, transportation and technology)
what is happening to the greenland ice sheet?
-it's melting.. -as of 2021, it is melting faster than any time in past 12,000 years, and has melted enough ice to cover florida in 2 inches of water
in the paris agreement, what do countries agree to?
-limit increase in global average temp to well below 2 degrees C -pursue efforts to limit the increase to 1.5 degrees C -aim to achieving net-zero emissions in the second half of the century
what is petra nova?
-located at a power plant outside of Houston -captures 90% of CO2 for an increase in oil production in the area
who is disproportionately affected by the effects of climate change?
-lower income -children -elderly -immunocompromised (e.g asthma,allergies) -rural areas -communities of color
Nordhaus assumes a discount rate of
3% per year
how can ecosystems mitigate extreme climate events such as wildfires, flooding, droughts?
-natural buffers -e.g reefs/barrier islands that protect coastal ecosystems from storm surges -e.g wetland ecosystems that absorb floodwaters
what are lagrange points?
-positions in space where objects sent there tend to stay put - gravitational pull of two large masses equals the centripetal force required for a small object to move with them
how is agriculture going to be affected by climate changes?
-reduced productivity overall -accelerate depletion of irrigation systems -intensify wildfires -expand distribution of pests and diseases
earth radiation management definition and implications
-suggests that negative effects of climate change can be offset by allowing heat to escape into space- for example, by thinning cirrus clouds by injecting ice nuclei -implications include injection of "too many" ice nucleating particles that may produce the opposite effect (thicker clouds that increase global warming)
how is the Pika being affected by climate change?
-the warming climate is causing the Pika to die off at elevations below 7,000 -in certain studies, more than 1/3 have disappeared in the past few decades
what is the IPCC "Water Top Ten"?
-water security is being affected physically and therefore exacerbating existing water-related vulnerabilities -extreme weather events that cause floods and droughts are more likely and more severe -negative changes in the hydrological cycle impact vulnerable populations more disproportionately -water-related risks increase with every degree of global warming -drought and flood risks increase with every degree of global warming -limiting global warming would reduce water-related risks -water adaptations have multiple benefits, but effectiveness falls under a certain threshold -effectiveness of water adaptations might be unclear -many mitigation strategies have a high water footprint -strong political support is needed
why did the keutsch group at harvard choose to use calcium carbonate as a stratospheric aerosol?
-white in color, mimics sulfur without negative impacts
during the last two decades, the global glacier mass loss rate exceeded _____ meter water equivalent compared to an average _____ meter water equivalent in 1950-2000.
0.5;0.33
Stern assumed a discount rate of
1.4% per year
Out of the CO2 emitted per year, ____ is removed naturally over the century, and ___ continues for +1000 years
1/2; 20%
by 2050, moderate (typically damaging) flooding is expected to occur on average, more than ____ times as often as it does today.
10
According to the most recent NOAA technical report: Sea level along the U.S. coastline is projected to rise, on average, _________________ in the next 30 years (2020 - 2050), which will be as much as the rise measured over the last 100 years (1920 - 2020).
10-12 inches
snow cover extent decreased by ___ per decade for 1967 to 2018.
13.4%
U.S forests and associated wood products currently absorb and store the equivalent of _____% of all carbon dioxide emitted by fossil fuels burning in the U.S each year
16
about ____ feet of sea level rise along the U.S coastline is increasingly likely between 2020 and 2100 because of emissions to date.
2
offsetting one CO2 doubling would require deflecting about _____ of the incident sunlight
2%
national climate plans were most likely only sufficient enough to limit warming to ________ degrees C.
2.7-3.7
about ____% more power is needed on a 90 degree day compared to an 80 degree day.
20-25
the IPCC estimates that ____% of the studied plant and animal species are at risk of extinction.
20-30
U.S emissions were high in ______, and fell 9% between ______ and ______ due to recession, coal to natural gas switch, and policy changes
2007, 2008-2012
The RCP 2.6 states emissions peak around ____ and then decline.
2020
Biden has pledged that the U.S will achieve net-zero emissions no later than _____.
2050
as of a 2015 study, agriculture contributes to _____ jobs and $ _____ annually to the U.S economy.
21 million;1 trillion
Population density in flood-prone coastal zones and megacities is expected to grow by ____ by 2050.
25%
oceans absorb about ____ of human CO2.
25%
in 2015, ____ of the world's population did not have access to safe drinking water.
29%
•Mitigation scenarios in which it is likely that the temperature change caused by anthropogenic GHG emissions can be kept to less than _______ °C relative to pre-industrial levels are characterized by atmospheric concentrations in 2100 of about ______ ppm CO2eq
2;450
which continent accounted for 2/3 of the global increase in emissions, as of 2017?
Asia
Regarding the NASA integrated system, what are the FORCINGS, the FEEDBACKS, and the TIPPING POINTS scientists need to examine?
Forcings: solar irradiance, GHG emissions, aerosols Feedbacks: clouds, precipitation, forest greening, ice albedo, water vapor Tipping Points: ocean circulation, sea level rise, ice loss, rapid methane release
Practical carbon policy implications: Stern vs Nordhaus
Nordhaus: $30/ton of carbon rising to $200/ton in 200 years Stern: $100/ton initially, rising to $950/ton in 200 years
what are the different Shared Socioeconomic Pathways (SSP's)?
SSP1: sustainability SSP2: middle of the road SSP3: regional rivalry SSP4: inequality SSP5: fossil-fueled development
______ suggested that we should cut back much more sharply on CO2 emissions than ______.
Stern/Nordhaus
which country had the biggest drop in emissions as of 2017?
U.S, because of higher renewables deployment.
What is defined as the adjustment in natural or human systems to a new or changing environment that exploits beneficial opportunities or moderates negative effects.
adaptation
why can't we just look at one sector to determine the effects of climate change in the U.S?
because of complex sectoral interactions; it is not possible to fully understand implications of climate change in the U.S without doing so
what are some barriers to adaptation?
climate change info and decision making divergent risk perceptions, cultures, and values -lack of leadership -institutional constraints -fragmentation of decision making -lack of resources to begin and sustain efforts
how would the east coast be affected by a sea level rise?
collision, overwash, inundation
The Mt Pintatubo Eruption of 1991 caused a worldwide _____ effect (cooling or heating)
cooling
what is the definition of growth discounting, and how can it be applied to global changes?
definition: if one saves money now by not building, one could invest this money somewhere else and make profit global changes: if society is 100 years richer from now than it is today, people at the time can afford to pay more than they can at the present
overall, species are shifting their breeding, migration, and nesting times ____ than historical trends (earlier or later)
earlier
what is controlled freeze zone (CFZ) technology, and how does it work?
efficiently removes impurities from natural gas and is less expensive than existing technologies removes CO2 and hydrogen sulfide-> CO2 is melted and distilled to recover valuable methane->CO2 is injected underground for sequestration or for use in enhanced oil recovery->discharges the CO2 as a high pressure liquid
historically, the _______ sector has accounted for 31% of emissions since 1990. since 2017, the ______ sector is now the largest contributor.
electricity generation ;transportation
how has the scientific understanding of climate changes evolved throughout the years?
energy balance models-> atmosphere ocean general circulation models-> earth system models
carbon dioxide is removed from the atmosphere by natural processes at a rate that is roughly ____ of the current rate of emissions from human activities.
half
climate changes have led to a range contraction for ___ of studied plants and animals
half
by 2100, global climate will modify plant communities covering almost ____ of Earth's land surface will drive the conversion of nearly _____% of land-based ecosystems from one to another
half;40
what are the 4 basic elements of risk assessment?
hazard (likelihood of incident, including interactions) inventory(properties, people, and the environmental risk) vulnerability (estimation of the losses from different scenarios by integrating biophysical info with socioeconomic and environmental info) loss (involves evaluation of exposure, sensitivity, and adaptive capacity for current and projected changes
how can heavy downpours lead to exposure to disease?
heavy downpours occur->waterways begin to rise, and can flood sewer and stormwater systems, which can back up to people's homes->floodwaters can become contaminated with agricultural waste, or contain disease already
using a ____ discount rate decreases the assessed benefit of action designed to reduce GHG emissions.
high
many area with ____ water availability have ___ levels of water security. WHY is this?
high; low increased flood risk, poor water quality, poor governance
how can extreme heat affect livestock and human health?
increased heat stress among animals and livestock, decreased milk production
what is carbon capture utilization and storage (CCUS)?
instead of storing carbon, it could be reused in industrial processes by converting it into something else (e.g graphene or engineered molecules)
what are stratospheric aerosols?
introducing small, reflective particles into the upper atmosphere to reflect some sunlight before it reaches the surface of the earth
what is a risk?
measure of likelihood that you will suffer harm from a hazard.
what are Coupled General Circulation Models (CGCM)?
models that combine the effects of the atmosphere and the oceans on climate (e.g sunlight, clouds, land masses, currents, GHG's, feedback loops, pollutants)
Where will Higher Temperatures will NOT occur in the future?
near the equator
as temps increase, the habitat ranges of many north american species move ____ and to ____ elevations
north;higher
why is geoengineering so controversial?
one area is positively benefitted while another area suffers the consequences (e.g U.S uses solar geoengineering to reduce global warming but Russia then suffers from drought and loses crop production)
what is time preference (inherent) discounting?
people still want their money now, instead of later
What is defined as the capability to anticipate, prepare for, respond to, and recover from significant multi-hazard threats with minimum damage to social well-being, the economy, and the environment.
resilience
The gas lifetime for methane is
short (10 years)
Fossil fuel emissions are _____ relative to fluxes in the terrestrial organic carbon cycle means that imbalances in the organic carbon cycle (e.g., deforestation, reforestation) can have a ______ effect on atmospheric CO2 levels
small; substantial
what is a discount rate?
the minimum interest rate set by the Federal Reserve for lending to other banks.
what can cause an ecosystem to change rapidly and irreversibly?
threshold, or tipping point has been passed
phenology
timing of important biological events (blooming, migration,hibernation)
How likely is it for the Earth's mean temperature to increase by 2.4-5.4 degrees C from preindustrial by 2100?
very likely
The gas lifetime for industrial Gases is
very long (100-1000 years)
What is defined as the degree to which a system is susceptible to, or unable to cope with, adverse effects of climate change, including climate variability and extremes. This is a function of the character, magnitude, and rate of climate variation to which a system is exposed, its sensitivity, and its adaptive capacity.
vulnerability
