Foundations Of Climate Change Flashcards
1
Q
We have high quality weather observations which are adequate over the last …. Years?
A
150 Years
2
Q
Earth has warmed by what *c since the late C19?
A
1.1*c
3
Q
As of 2021, the warmest year on record was ___? Followed by ___ & ____
A
1st : 2016
2nd : 2020
3rd: 2019
4
Q
Proportion of the world which lives in N.Hemisphere
A
85%
5
Q
What % of heat trapped by GHGs goes into heating the oceans?
A
93%
6
Q
IPCC has determined that the confidence in the warming of the climate system in early C20 is…
A
Unequivocal
7
Q
Tree rings are what colour in spring and what colour in autumn?
A
Spring - light coloured growth
Autumn - darker colour growth
8
Q
Speleothems are what sort of structure?
A
Cave structures
9
Q
Climate measurements only go back 170 years - name 5 other techniques:
A
- Tree Rings
- Corals
- Speleothems (caves)
- Ice Cores
- Ocean Sediment Cores
10
Q
How far do ice cores go back?
A
Past million years
11
Q
Ocean sediment cores go back how many years?
A
Tens of millions of years
12
Q
How many years ago was the Earth much warmer than today?
A
50 million
13
Q
50 million years ago the Earth was…
A
Much warmer - no permanent ice
14
Q
The planet cycles between ice ages and interglacial periods - each period is how many years
A
C. 100,000
15
Q
When did the last ice age reach its coldest point? When did it end?
A
Coldest peak - 20,000 years ago
Ended 10,000 years ago
16
Q
The last 11,000 years are known as the ___?
When did temperatures peak?
A
Holocene
Temperatures peaked around 7,000 years ago
17
Q
When was the little ice age?
A
200-300 years ago
18
Q
What is the average difference between the Ice Age & Interglacial periods?
A
6*c
19
Q
The 1*c of warming since the Little Ice Age is happening at a much more rapid rate…what is the rate?
A
X16 faster than out of the Ice Ages
20
Q
Sunlight is absorbed by the Earth, at what W/m2?
A
340 W/m2
21
Q
What % of the Earth’s sunlight is reflected back to space by clouds / reflective elements?
A
30%
22
Q
What is the net solar energy absorbed by the Earth’s surface?
A
238 W/m2
23
Q
Who recognised that the Earth had to be radiating an equal amount of energy to space (infrared radiation)?
A
Fourier
24
Q
When did Fourier realise that GHGs reduced the amount of power than Earth radiated to space?
A
1820s
25
Possibility of the greenhouse effect was first recognised in 1896 by and was furthered in 1940 by?
1896 - Arrhenius
1940s - Callendar
26
Majority of the atmosphere contains what three gases?
Nitrogen (N2)
Oxygen (O2)
Argon (Ar)
27
Minor constituents of the atmosphere cause the greenhouse effect - which is the most important GHG?
Water vapour - most important GHG, trapping the most heat
28
The monitoring of CO2 is done on what curve? It has been measured since when?
Keeling Curve - measured since mid-C20
29
For the past 50 years the increase in CO2 each year averages what % of what humans released into the atmosphere that year?
44%
30
What proportion of CO2 emitted is absorbed by oceans ?
1/4
31
All carbon dioxide molecules have six protons - however different sources of carbon dioxide contain different numbers of neutrons. Name x3 types
Carbon 12 - x6 neutrons
Carbon 13 - x7 neutrons
Carbon 14 - x8 neutrons
32
Air bubbles trapped in glacial ice - in late C18 there was 280ppm
By 2020, humans increased atmospheric CO2 by what ppm and what %?
Increased by 135ppm, 45%
33
Each KG of methane traps as much heat as how many KGs of CO2?
28KG
34
Pre-industrial methane levels were ___ ppm? In 2020 these levels were ____ ppm?
Pre-industrial: 0.8ppm
| 2020: 1.9ppm
35
Ozone has the ability to absorb what time of radiation?
| Humans do not emit ozone
Absorb ultraviolet radiation
36
Name x3 types of aerosols and where they come from…
Surface aerosols (sulfur released from FFs)
Black carbon aerosols (soot)
Mineral dust (agri activities, changes in water features, cement production)
37
Atmosphere lifetime of Carbon Dioxide
500 years
38
Atmospheric lifetime of methane
12.4 years
39
Atmospheric lifetime of nitrous oxide
121 years
40
Atmospheric lifetime of halocarbons
Years to millenia
41
Atmospheric lifetime of ozone
Weeks to months
42
GWP of the following gases:
- Methane
- Nitrous Oxide
- Halocarbons
Methane - 28
Nitrous Oxide - 265
Halocarbons - 100s to 1000s
43
Increase in abundance since pre-industrial times:
- CO2
- Methane
- Nitrous Oxide, Halocarbons, Ozone
CO2: 130ppm
Methane: 1.1ppm
Other: ppb
44
Fraction of total greenhouse radiative forcing
- CO2
- Methane
- Nitrous Oxide
- Halocarbons
- Ozone
```
CO2: 56%
CH4: 15%
NO2: 5%
Halocarbons: 11%
Ozone: 12%
```
45
Anthropogenic changes to radiative forcing quantify…
Difference between the incoming energy absorbed by Earth and outgoing infrared radiation
46
CO2 & GHGs have caused a positive change to radiative forcing of __ W/M2
3 W/M2
47
Aerosols have caused a negative change to radiative forcing ____ W/M2?
0.75 W/M2
48
Net human contribution to radiative forcing is ___ W/M2?
2.25 W/M2
49
What does water vapour do to the Earth’s temperature? What is this process called?
Water vapour feedback
Main role is to amplify changes caused by increasing CO2
50
Climate has experienced cyclical patterns:
Tectonic processes - explain
Tectonic processes can substantially alter arrangement of continents - ice sheets are reflective
51
Output of the sun can be attributed to warming in what way…
Scientists have been measuring the output of the sun since when…
Scientists have been measuring the output of the sun since late 1970s
Suns output has changed little over the past few hundred years - doesn’t explain warming period
52
Orbital variations can be impacted by the Earth-sun distance, name x3 ways how:
1. Shape of orbit
2. Tilt of Earth
3. Date of closest approach
53
Shape of Earth’s orbit becomes more and less elliptical every ____ years
100,000 years
54
Tilt of the Earth is around what degrees currently
Cycles vary between X and Y every how many years
Tilt is currently 23.5*
Cycles between 22.3* and 24.5*
Tilts around every 41,000 years
55
Date of closest approach is currently in what month?
Cycles though the calendar year over how many years?
January
23,000 years
56
El Niño and La Niña - which is the warmer period? How long do they last?
El Niño - warmer period
La Niña - colder period
Last around a year
57
IPCC’s 2013 summary statement on warming attribution identified that:
‘_____ that ____ of the observed increased in global average surface temperature from _______ was caused by anthropogenic increase in GHG concentrations and other anthropogenic forcing together.’
Extremely likely that…
More than half…
Global average surface temperature from 1951 to 2010…
58
Extremely like = what confidence %?
95%
59
Who set up the SSP 1-5 shared socioeconomic pathways?
Integrated Assessment Modelling Consortium
60
```
Temperature Increases:
SSP 1
SSP 2
SSP 3
SSP 5
```
SSP 1 - 2*c
SSP 2 - 3*c
SSP 3 - 4.5*c
SSP 5 - 5.5*c
61
Describe SSP 1
- general overview
- emissions peak
- temp increase
Sustainable World - gradually shift to decarbonise
Emissions peak now
Emissions go negative in 2075
Temperature increase of 2’c
62
Describe SS2
- general
- temperature increase
Follows trends of world today - general decline in GHGs as renewable energy adoption increases
Economic growth similar to SSP1
Temperature increase of 3*c
63
SSP3 describe
- general
- temperature increase
- emissions
Economic Inequality - increasing conflict between nations
Economic growth is slow, adaptation of new technology slow
Emissions double today’s in 2100
Temperature increase of 4.5*c
64
SSP5 describe
- general description
- temperature increase
- emissions
BAU focused on economic growth > sustainability
Fossil fuels power a significant fraction of the growth
Emissions triple today’s values in 2100
Temperature increase of 5.5*c
65
Temperature difference between SSP1 to SSP5
Nearly 4*c temperature difference (2*c to 5.5*+)
66
What warming do we control?
We control the warming in the second half of C21 -
Lag means warming over the next few decades is largely determined by past investment
67
Example of the impacts of heatwaves
2003 heatwaves in Europe - caused 10s of thousands of excess deaths
68
Global precipitation projected to increase by Xm for every degree Celsius of global average warming?
3m
69
IPCC’s 5th Assessment Report suggests sea level will rise ____ above today’s levels by 2100
What proportion of Florida would be flooded at high tide under this estimation?
Sea level will rise 45-75cm above today’s levels by 2100
9% of Florida’s land
70
Describe ice melt -
What will the impact of C21 warming be on ice melt?
Ice melts slowly, this is just a fraction of how much sea level rise we are committed to
May take millennia for sea level to fully respond to the warming of C21, or more rapid under tipping point scenario
71
How is ocean acidification caused?
What is the impact?
In liquid environments, carbon dioxide is converted to carbonic acid
Ocean pH drops, harder for calcifying species - can be fatal for some
72
How can you quantitatively determine what role climate plays in extreme events?
What do you need?
Extreme-event attribution science
1. Statistical analysis of historical climate
2. Physics of the phenomenon
3. Computer Simulations
73
Estimated that rainfall from Hurricane Harvey was x% greater due to climate change?
15% greater due to climate change
74
Who has concluded that most extreme events have been affected by climate change?
AMETSOC
75
When was the last climate tipping point?
What happened to temperatures in the Northern Hemisphere?
Last ice age - 12,000 years ago
N.Hemisphere plunged several degrees due to disrupted ocean currents
76
Describe some potential abrupt changes should a tipping point occur:
- Shutdown of Gulf Stream
- Disintegration of Greenland Ice Sheets
- Thawing of permafrost
- Shift in timing & magnitude of Indian monsoon
77
What is carbon intensity?
Amount of carbon dioxide produced per unit of energy generated
78
What is the highest carbon intense fuel - rank them
Coal
Oil
Natural Gas
79
To satisfy the Earth’s energy requirements, what area of solar energy collectors is required? What proportion of the Earth’s surface is this?
1million Km2
| 0.2% of Earth’s surface
80
What is a logical short term solution for solving intermittency?
What is the longer term solution?
Short term - natural gas
Long term - energy storage technologies
81
What are the key challenges of biomass energy?
- getting to a large scale
| - additional land typically comes from clearing forests
82
What proportion of the world’s energy is generated on hydroelectricity?
16%
83
What is the key challenge for hydroelectricity?
Many of the world’s big rivers already dammed - new dams cause local issues & opposition
84
Nuclear generates what proportion of the world’s electricity?
2018
85
Where is CO2 from CCS injected?
Underground in depleted oil and gas fields, coal beds that cannot be mined or deep saline formations
86
Solar Radiation management - what is the mechanism?
Injection of sulfur into the stratosphere
87
What does the injection of sulfur into the stratosphere do?
Reacts with ambient water Vapor to form droplets, which reflect sunlight back to space
88
What are the side effects of solar radiation management?
Changing precipitation patterns
Potential for droughts
Governance nightmare
Political destabilisation
89
What is a disadvantage of carbon dioxide removal schemes?
Required scale is enormous - we add 40bn tonnes of CO2 into atmosphere pa
90
Carbon dioxide removal - differences from CCS
CCS captures exhaust gas of a power plant
Carbon dioxide air capture removes carbon from the free atmosphere
91
What is BECCS
Bio energy with CCS
Plants burned to produce power - carbon sequestered using CCS tech
92
What has the Biden administration committed to the US doing?
Cutting overall GHG by 50% below 2005 levels by 2030
Net zero 2050
93
What has the EU committed to in emissions reductions?
Reduced 55% in 2030 below 1990 levels
94
When has China agreed to level off emissions
2030
95
What do our NDC commitments currently put us on track for warming wise?
2.5-3*c by 2100
96
For every trillion tonnes of CO2 emitted, warming goes up by ___
0.3-0.6*c
97
How much CO2 has been emitted between the industrial revolution and 2017?
2.2 trillion tonnes
98
What is our emissions budget for…?
- 2*c
- 1.5*c
2*c : 1.5trillion tonnes
1.5*c : 580 billion tonnes
99
We cannot reach either a 2*c nor 1.5*c target without…
The ability to generate large negative emissions
