key words Flashcards
(70 cards)
1
Q
radiative forcing
( total: 2.84 W/m2
human: 2.72 W/m2 )
A
the change in Ein - Eout for the planet as a result of some change imposed on the planet before the temperature of the planet has adjusted in response
- positive => Earth receives more incoming energy from sunlight than it radiates to space => global warming.
-negative => that Earth loses more energy to space than it receives from the sun => cooling
2
Q
inertia / time lag
A
varying timescales exist in the Earth’s response to emissions of greenhouse gases – with some aspects of the climate responding almost instantaneously, while others may take decades or more
3
Q
thermohaline circulation
A
the ocean circulation which is driven by fluxes of heat and freshwater across the sea surface and subsequent interior mixing of heat and salt
4
Q
general circulation model
A
mathematical models that attempt to simulate the Earth’s climate system
5
Q
GDP gross domestic product
A
wealth= more spending = more CO2 release
production of anything requires energy - derived from combustion of fossil fuels → releasing CO2 in
atmosphere
6
Q
kaya identity framework
I = P x A x T
A
total GHG atmosphere = population x affluence (gdp pp) x ghg intensity
ghg intensity (T) = carbon intensity x energy intensity
7
Q
transient climate response
A
- temp change at the time of CO2 doubling and the equilibrium climate sensitivity
- assuming atmospheric CO₂ concentrations increase at a steady rate of 1% per year over about 70 years
=> (which is roughly the time it takes for CO₂ to double under this scenario)
8
Q
SSPs (Shared Socioeconomic Pathways)
=>-depends on what policies will be put in place
=>uncertainty on carbon feedback
A
- Set of scenarios describing alternative futures of
societal development (very low to very high) - Used by IPCC to model different possible
emission trajectories - These scenarios are referred to as SSPx-y, ‘y’ refers to the approximate level of radiative forcing (in W/m²)
9
Q
internal climate variability
A
the natural variability of the climate system that occurs in the absence of evolving external forcing and includes processes intrinsic to the atmosphere, ocean, land, and cryosphere and their interactions
eg.el nino, la nina, AMOC
10
Q
what determines carbon intensity, how does it affect climate change?
A
- GHG emitted per joule of energy generated
- influenced by energy generation technology used
11
Q
GDP
A
standard measure of the value added created through the production of goods and services in a country during a certain period.
=> more production => more GHG emmited
12
Q
How well did past climate models perform in projecting global warming in the years after they were published by comparing them to observed temperature changes?
A
According to Hausfather, the warming that the world has experienced is pretty much exactly what climate models predicted it would be as much as 30 years ago
13
Q
uncertainties in climate projections:
A
- variability in climate sensitivity
- different future emission pathways (ssp’s)
- carbon cycle feedbacks
- natural climate varibility
14
Q
climate sensitivity
A
measure of earths climate response to GHG emission increases
- can affect magnitude and pace
Higher sensitivity = faster warming, meaning stronger climate action is needed
Factors determining climate sensitivity:
- radiative forcing
- climate feedback
- time lags
15
Q
energy intensity
A
- amount of energy (joules) needed to generate one dollar of goods and services
- influenced by economic activities and energy efficiency
16
Q
how do carbon cycle models contribute to climate predictions?
A
- Carbon cycle models simulate how CO₂ moves between the atmosphere, oceans, land, and biosphere.
- help predict future CO₂ levels by tracking carbon sources (fossil fuels, deforestation) and carbon sinks (oceans, forests, soils)
- These models feed data into climate models to estimate temperature rise, extreme weather, and feedback loops (e.g., permafrost melting).
- also test the impact of climate policies like carbon capture and reforestation to assess if warming can be limited to 1.5°C or 2°C.
17
Q
Atmospheric retention
A
how long gases stay in Earth’s atmosphere before they are removed or broken down. Different gases have different retention times, depending on their properties and interactions with the environment.
18
Q
scenario uncertainty
(SSP’s)
A
- different pathways of future emissions (and resulting future forcing).
- IPCC’s fifth assessment report uses what they called illustrative scenarios. => Hence part if the future temperature range is due to the use of the use of five different emissions scenarios.
19
Q
model uncertainty
A
- uncertainty in the response of the climate system to a radiative forcing scenario.
- Each model has its own climate sensitivity due to choices made by modeling teams regarding important feedback processes
- These variations in feedback processes lead to different climate responses and climate sensitivities
20
Q
equilibrium climate sensitivity
A
the long-term global warming caused by a doubling of carbon dioxide above its pre-industrial concentration
global warming = initial warming + feedbacks
21
Q
social tipping points
A
moments in a social-ecological system (SES) when small quantitative changes trigger non-linear, self-reinforcing changes that lead to a new social state
=> Examples given include historical shifts such as the abolition of the transatlantic slave trade
22
Q
Social tipping interventions (STIs)
A
can trigger self-reinforcing processes leading to rapid societal transformation.
Key Social Tipping Elements (STEs)
Expensive Shoes, Fake Nails, Endless Instagrams (ESFNEI)
- Energy Production and Storage: Remove fossil fuel subsidies and support decentralized energy generation.
- Human Settlements: Build carbon-neutral cities with sustainable infrastructure.
- Financial Markets: Divest from fossil fuels and redirect investments toward low-carbon solutions.
- Norms and Values System: Promote recognition of fossil fuels as unethical to shift social behavior.
- Education System: Strengthen climate education and engagement at all levels.
- Information Feedbacks: Increase transparency in greenhouse gas emissions to influence consumer behavior.
23
Q
otto et al paper on climate action
A
- argues that climate action should not just be top-down (government mandates) but also bottom-up (societal shifts in norms, values, and markets)
- social tipping interventions, once triggered, can accelerate their own impact through positive feedback mechanisms
- climate action cannot rely on a single lever but instead must activate multiple tipping elements in finance, infrastructure, policy, education, and social norms
24
Q
European Investment Bank’s and ABP’s decisions to phase out fossil fuel financing
A
- EIB world’s largest multilateral financial institution, making its move to cut fossil fuel financing
=> landmark shift in the financial landscape - ending oil, gas, and coal project financing after 2021, the EIB is aligning its lending with the Paris Agreement, signaling to both public and private investors that fossil fuel projects** no longer have long-term financial viability**
- redirect capital toward renewables, energy efficiency, and sustainable infrastructure
25
carbon budget
the total amount of carbon emissions that can be emitted for temperatures to stay below a certain long-term warming limit
26
emissions gap
the difference between where global greenhouse gas (GHG) emissions are heading
and where science indicates emissions should be in 2030
27
draw down project
research organization that identifies and ranks the most effective climate solutions to reverse global warming.
28
social ecological system
system where humans (society) and nature (ecosystems) interact dynamically.
29
social economic system
system where society and the economy interact, influencing each other through policies, markets, and social structures. It explains how economic activities impact social well-being and vice versa.
30
European investment bank
31
cascading tipping points
occurs when passing one tipping point triggers at least one other tipping point
32
decarbonization
Decarbonization refers to the process of reducing or eliminating carbon dioxide (CO₂) emissions from economic activities, primarily by shifting away from fossil fuels and adopting low-carbon solutions.
33
systemic tranformation
the transformation of a system to create a lasting difference
34
social unrest
civil disorders, acts of mass civil disobedience, and strikes
35
What is radiative forcing and how/why did it change since preindustrial times?
Human factors:
- Green house gasses ⇒ positive radiative forcing (warming)
- Aerosols ⇒ negative radiative forcing (cooling)
- Human activities (like burning fossil fuels and biomass) have increased the number of aerosols in the atmosphere.
⇒ enhance cloud reflection increasing albedo
Land-Use Change:
- Deforestation and other land-use changes have increased the Earth's albedo, resulting in a negative radiative forcing
- Natural Factors:
- Solar variations and volcanic eruptions
36
Committed warming
the future warming to which we have committed ourselves by virtue of past human activities
37
What happens to radiative balance if greenhouse gasses are added to the atmosphere?
- Greenhouse gases absorb some of the outgoing energy (Eout) and redirect part of it back to the surface instead of letting it escape to space
=> reduces amount of energy leaving the planet => imbalance => Ein > Eout
- planet starts accumulating heat => causes temperatures to rise over time
=> radiates more energy because warmer objects emit more heat
=> planet gets hot enough that Eout increases to match Ein again
radiative balance is restored—but at a higher temperature
38
What is the (coupled nature of the) climate system?
"All Legendary Hoes Collect Birkins" (ALHCB)
- atmosphere
- lithosphere (rocky layer)
- hydrosphere (all water)
- cryosphere (frozen water)
- biosphere (life supporting part)
⇒ one being affected will always affect the others (they are all connected)
⇒ it operates as a system
39
feedbacks
Happens after forcing
can amplify or reduce climate changes. For example, warming melts ice, which means less sunlight is reflected, causing even more warming
40
time lag
- climate does not change instantly
when energy balance shifts
- oceans absorb heat slowly, so it takes time for the climate to reach a new balance
41
Unforced Variability
- The climate can change naturally without an outside cause.
-eg. El Niño causes temporary warming and changes in weather patterns, even though no extra energy is added to the system.
42
climate models
a computer simulation of the Earth's climate system, including the atmosphere, ocean, land and ice
43
General circulation models
used to look at only ocean or atmosphere now they look at them together
- simulate the physics of the climate itself
- capture the flows of air and water in the atmosphere or the oceans, as well as the transfer of heat
44
emergent properties
properties that are not evident in the individual components of a system, but show up when combining those components
45
upwelling & downwelling
90% of heat is absorbed by the ocean (biggest sink)
up: (rich in marine life)
is a process in which deep, cold (nutritions) water rises toward the surface
- wind blows warm water => cold water takes its place
=> windblown coastlines
down:
is where surface water is forced downwards, where it may deliver oxygen to deeper water
46
ocean => heat & distribution
- moving heat from the equator toward the poles, moderating global temperatures and influencing regional climates
- achieved through both wind-driven currents and the thermohaline circulation
- ocean stores much of the heat trapped by greenhouse gases
47
ocean => carbon cycle
- ocean is a significant carbon sink (30%)
- absorbing a large amount of carbon dioxide (CO2) from the atmosphere => dissolves it
-mixed layer (100m) =>exchanges carbon rapidly with atmosphere + deep ocean
-deep layer (stores more carbon) (more slow)
48
Ocean-Atmosphere Interactions
- exchange of heat, water, gases between ocean and atmosphere
=> affects weather
=>evaporation of water from ocean's surface adds water vapour to atmosphere (GHG)
49
density => salinity and temperature
high salinity low temp => dense => heavy => sink to the bottom
50
ocean gyres
a large system of rotating ocean currents
51
thermohaline circulation
largest ocean circulation pattern that depends on temp + salinity of water
-starts at Iceland with cold and salty water sinking to antartica and around the world till its in the north making it warm again and move back up to the north pole
- moving large amounts of water
- distributes heat along the way
- 1 particle takes 1000 years
52
Atlantic Meridional Overturning Circulation (AMOC)
=> part of thermohaline circulation
- near iceland
53
el nino (ENSO)
overall warming (christmas time)
ocean temperatures in the central and eastern Pacific become warmer than usual, disrupting global weather patterns
- Weakened trade winds → Warm water moves east toward South America.
- Warmer ocean temperatures → Less upwelling of cold, nutrient-rich water.
- Disrupts normal atmospheric circulation (Walker Circulation).
Effects:
🌧️ Heavy rainfall & flooding – In South America (Peru, Ecuador).
🔥 Droughts & wildfires – In Australia, Indonesia, and parts of Africa.
🌊 Weaker fisheries – Less cold water = fewer nutrients = marine life declines.
🌪️ Stronger hurricanes in the Pacific – But weaker hurricanes in the Atlantic.
54
la nina
occurs when strong trade winds push warm surface waters toward Asia, allowing cold, deep ocean water to rise in the eastern Pacific
🔹 Causes:
Stronger trade winds → Push warm water west (toward Indonesia/Australia).
Upwelling increases → Cold, nutrient-rich water rises in the eastern Pacific.
Strengthened Walker Circulation → More intense air circulation between Pacific regions.
🔹 Effects:
🌧️ More rain & flooding – In Australia, Indonesia, Southeast Asia.
🔥 Drier conditions & droughts – In South America & parts of the U.S.
🌊 Stronger Atlantic hurricanes – La Niña fuels more storms in the Atlantic.
🐟 Boosted fisheries – Cold, nutrient-rich water increases marine life productivity.
55
climate feedback
response to climate forcing either amplifying (positive) it or reducing (negative) it ⇒ initial change is fed back into
Positive: A positive feedback amplifies an initial warming ⇒ a change in one climate quantity causes a change in a second, and the change in the second quantity ultimately leads to an additional change in the first
Negative: A negative feedback reduces an initial warming. In other words, a change in one climate quantity causes a change in a second, and the change in the second quantity ultimately leads to an opposing change in the first
Fast Feedbacks: Fast feedbacks respond rapidly to changes in surface temperature, meaning they will play an important role in climate change over the coming century.
Slow Feedbacks: Slow feedbacks respond slowly to increasing surface temperature and require long periods of warmth before they significantly alter energy in or energy out (millennia)
56
positive feedbacks
- Ice-albedo feedback (sea ice/ice sheets): As ice melts, a darker surface such as the ocean is exposed, which decreases the planet's albedo, leading to more solar radiation being absorbed and additional warming
- Water-vapour feedback: A warmer atmosphere can hold more water vapour. Because water vapour is a greenhouse gas, increased atmospheric humidity leads to further warming
- Carbon cycle feedback: As the planet warms, there is a risk of the release of large amounts of carbon dioxide and methane that are currently frozen in the ground or otherwise sequestered. The release of these greenhouse gases leads to more warming and the further release of greenhouse gases
- permafrost (thick subsurface layer of soil that remains below freezing point throughout the year) releasing that carbon into the atmosphere as the greenhouse gases carbon dioxide or methane. Once in the atmosphere, these greenhouse gases further warm the planet, creating a positive feedback loop that thaws more permafrost.
-cloud feedback (net positive): clouds block outgoing energy
57
negative feedbacks
- Chemical weathering: Increased rainfall due to a warming planet increases the rate of chemical weathering, which removes carbon dioxide from the atmosphere. This reduction in atmospheric carbon dioxide acts to offset some of the initial warming
- cloud feedback: water vapour reflect sunlight
58
why AR6 is better than AR5?
-SSP's for policy making
- carbon budget 1.5-2
59
fast feedbacks
- ice-albedo feedback (associated with snow and sea ice) (+)
- water-vapour feedback (+)
- cloud feedback (+/-)
- lapse rate (-)
60
slow feedbacks
- ice-albedo feedback associated with land ice sheets (+)
- the release of carbon dioxide and methane from thawing permafrost (+)
- chemical weathering (-)
- ocean carbon sink (+)
- biosphere carbon sink (+)
61
Measure Climate Sensitivity
1. Equilibrium Climate Sensitivity (ECS)
- The long-term warming once the Earth fully adjusts to doubled CO₂.
- Best estimate: 3°C warming (likely range: 2.5°C to 4°C)
2. Transient Climate Response (TCR)
- How much warming happens over about 70 years as CO₂ gradually doubles.
- Best estimate: 1.8°C (range: 1.4°C to 2.2°C)
62
climate tipping points
critical thresholds in the climate system that, when exceeded, can lead to abrupt, self-perpetuating, and often irreversible changes
key driver ⇒ positive feedback loops
63
Cascading tipping points
Crossing a threshold in one part of the climate system may trigger another tipping element to tip into a new state (domino effect)
⇒ one tipping point will affect other tipping point
64
climate tipping points examples
cryosphere:
- Ice sheet collapse:
- Antarctic: it is vulnerable to collapse, lead to a rapid and substantial rise in sea level
- Greenland Ice Sheet: experiencing mass loss, which is virtually certain to continue under all scenarios => irreversible for millennia.
ocean atmosphere:
- Shutdown of the Atlantic Meridional Overturning Circulation (AMOC)
biosphere:
- Amazon Rainforest Dieback:
- Deforestation and climate change are destabilizing the Amazon rainforest. A tipping point could lead to a shift from rainforest to a drier state, such as a savanna
=> major loss of biodiversity and the release of large amounts of carbon into the atmosphere
65
natural processes that significantly affected our climate since pre-industrial times
- volcanic eruptions: short-term cooling effect by releasing aerosols into the upper atmosphere, which reflect sunlight
- Variations in the sun's energy output: solar constant
- climate variability refers to natural fluctuations within the climate system, like El Niño/Southern Oscillation (ENSO)
- (greenhouse gas) Natural carbon cycle processes on land and in the oceans have also had a major impact on climate. These processes have removed about half of the CO2 emitted by human activities, thereby slowing down global warming
- plate tectonics: ocean currents
- earths orbit: eccentricity, obliquity (angle)
more elliptical (more oval) lower solar constant more eccentric
more sun light hitting polar regions
66
external climate variability
Climate variations caused by external forcing, which alters the Earth’s radiation balance
67
evidence for the claim that the observed climate change is caused by humans
90-100%
climate models cannot show present day warming without human factors affecting the planet
- 2019, atmospheric concentrations reached 410 ppm for carbon dioxide (CO2)
- decrease in Arctic sea ice
68
How do you assess scientific consensus on climate change?
cook et al 2016
only looked at ones used a definitive conclusion
- expertise
- peer reviewed
- domain experts (climate scientists)
- On what grounds is the consensus being questioned? For example, by Tol (-> discussed in the paper by Cook et al 2016)?
- described uncertainties as nothing at all
- Why do you think that an accurate understanding of scientific consensus is important for public climate literacy?
- lack of confirmation = disagreement
69
tobacco strategy
- A deliberate misinformation campaign used by industries to cast doubt on science and delay regulations
✅ Manufacturing Doubt
✅ Hiring Fake Experts misinformation
✅ Cherry-Picking Data
✅ Lobbying & Delays
70
