Climate Change Flashcards
climate change=
give an example
long-term variations of the average weather conditions experienced in a particular region
example: Edmonton has milder winters than 30yrs ago
global warming=
increase over time in the average temp across the entire planet
example: the planet as a whole is on average 1C warmer than it was in 1880
explain the positive feedback loop of ice melting
ice melts –> albedo decreases because more land is exposed –> more solar radiation is absorbed –> warming –> more ice melts
list 5 factors/ events that can cause climatic shifts
- variations in solar output
- variations in earth’s orbit
- volcanic events
- meteorite events
- anthropogenic greenhouse gas emissions
dust, smoke, and fog in the atmosphere are called ___
They absorb ____ _____
aerosols
shortwave radiation
Clouds alter the amount of sun that makes it to the surface. How?
they reflect shortwave radiation back out
the amount of _____ ____ we receive from the sun varies on a daily, yearly, decadal, centennial, and millennial basis
solar radiation
Changes in ___ ____ _____ (TSI) are caused by changes in activity of ___ and ___
total solar irradiance
sunspots
faculae
sunspots=
dark spots on the surface of the sun in which magnetic forces are very strong and block the hot solar plasma; they are cooler and darker than their surroundings (so absorb more heat)
more sunspots = ___(more/less) faculae = ___ (increased/ decreased) TSI
more
increased (solar output)
what is the average TSI? (total solar radiance)
1368 W/m2
When was the little ice age? Why did it occur?
16th to mid-19th century
- caused by increased volcanic activity and fewer sunspots
Eccentricity=
our orbit around the sun is eccentric (it changes over time)
Regarding Eccentricity;
There is currently a 3% (5million km) difference between perihelion and aphelion
Perihelion=
Aphelion=
This difference equates to a __% difference in the solar radiation reaching the Earth in perihelion vs aphelion
perihelion= closest to the sun
aphelion= furthest from the sun
6%
Earth’s orbit cycles between circular and elliptical about every ___ yrs, from __ (circular) to ___ (slightly elliptical)
100,000yrs
0-0.07
Is the sun ever right in the middle of earth’s orbit?
When is the difference between perihelion and aphelion larger?
no it’s not
The difference b/w perihelion and aphelion increases as eccentricity increases
The obliquity is:
does it change? If so, by how much?
the tilt of the earth
yes
cycles every 40,000 years between 24.5 degrees to 22.1 degrees
What obliquity are we currently at?
high angle=
low angle=
23.5 degrees
high= more extreme seasons (cold winters, hot summers)
low= mild seasons (cool summers, warm winters- ice sheets form here because snow can accumulate during the cool summers)
precession is:
cycle spans___ yrs
changes in the orientation of the Earth’s axis
25,000yrs
precession can alter:
1.
2.
1, the position of the earth with respect to perihelion and aphelion
2. which hemisphere is facing the sun at each point
Milankovitch cycles=
example:
regular cycling of the eccentricity, obliquity, and precession of earth’s orbit drives glacial and interglacial periods
example= Pleistocene glaciation
volcanic eruptions produce ___ ___ and __ ___ which can cause cooling. How?
sulfuric gas (sulfate aerosols)
volcanic ash (tiny particles of rock and glass)
cause cooling:
- decrease tropospheric temp
- alter radiation balance on earth
- alters atmospheric cycling
In 1999, Mount ___ in ___ erupted, which caused the Earth to cool by 0.5C for 2 years! Why did that occur?
Mt Pinatubo in the Philippines
- sulfate aerosols etc in the plume of smoke scattered incoming solar radiation (acts as a sun shield)
- when these gases enter the stratosphere, they stay there for years
Volcanoes can cause cooling, but can they cause warming? If so, how?
yes!
they produce water vapor and carbon dioxide, which are greenhouse gases and aid in heat retention
T/F
meteorite strikes can have similar effects as volcanic events concerning climate
Explain
true!
- they create clouds upon impact (can block solar radiation for months)
- can create shock waves that can disrupt ecosystem structure
The Chicxulub crater was formed by a meteor about __-__Ma in ___
65-66 million yrs ago
Mexico
65-66Ma layer of sandstones has high concentrations of ___
What does this imply?
iridium
Lots of meteorites hit around the same time= cretaceous-Paleogene boundary and mass extinction event
The main drivers of climate change are no longer ___ ___ cycles, but massive and rapid _____ ____ ____ emissions
evidence of this?
Milankovitch’s orbital cycles
now: anthropogenic greenhouse gas emissions
evidence:
usually insolation and heat distribution is affected on a scale of tens of thousands of years
- outside of the natural trajectory
CO2 is:
a) the most abundant greenhouse gas
b) lasts a long time in the atmosphere
c) is the most potent greenhouse gas
d) is responsible for 2/3 of our energy cycle imbalance
e) all of the above
f) a, b, d
f
List the 6 main greenhouse gases in order from least potent to most potent
- CO2
- water vapor
- methane (CH4)
- Nitrous oxide (N2O)
- Ozone
- CFCs
The Keeling curve shows us that:
atmospheric CO2 is increasing (latest reading= 414.86ppm)
T/F
concentrations of most of the greenhouse gases are increasing
- give 2 reasoning why they are or aren’t
true
- use of fossil fuels etc has been increasing
- forestry and other land use is increasing (trees are carbon sinks!)
In Canada, which sectors are the largest GHG emitters?
oil & gas, and transport
Climate change is impacting crops in __ regions more than crops in ___ regions
temperate
worse than
tropical
What’s happening to communities in marine ecosystems as a result of climate change?
waters are warming, so many marine animals are moving towards the poles to stay in cooler water
- but some species will also move into the warmer waters (non-bony fish that are adapting)
- this causes an overall change in the communities
T/F
the relationship between the cumulative CO2 emissions and global warming is almost linear
true
Across warming levels, ___ areas warm more than ____
The ___(poles/ tropics) warm faster than the (poles/ tropics)
land
oceans
poles
tropics
precipitation is projected to __(inc/dec) over high latitudes, the equatorial pacific, and parts of the monsoon regions, but ___ (inc/dec) over parts of the subtropics and in limited areas of the tropics
increase
decrease
oceans are acidifying because of increased ___ dissolved in them
CO2
food availability will change in the future, especially in the ___ hemisphere
- list 4 reasons why
southern
- overfishing
- crop yields decreasing
- loss of coastal areas
- loss of crops to urrbanization
Ecosystems are predicted to be affected by climate change in the following ways:
- increased __ and __ in boreal forests
- thawing of _____
- species ____, especially on the prairie and other flat landscapes
- increased ____/ water scarcity
- pests and fires
- permafrost
- extinctions
- drought
The _____ was created by the UN in 1998 and is the world’s top authority on climate science .
What do they do?
IPCC (intergovernmental panel on climate change)
- spell out specific scientific findings that help policymaking decisions
- must remain neutral and can’t suggest any particular political action (can’t tell leaders what to do, only what CAN be done)
What is the Paris Agreement?
Legally binding international treaty (192 countries) that sets long-term goals to:
- reduce GHG to limit the global temp increase in this century to 2C (1.5C even better)
- provide financing to developing countries to mitigate climate change
Are we on track to limit warming to 1.5C?
No :(
try for 2C
What sectors should we target to make these changes happen?
- industry
- electricity and heat production
- agriculture, forestry, and other land uses
How can we make industry reduce CO2 emissions?
tax! Don’t make it free to pollute
- if CO2 production is expensive, they’ll find ways to reduce emissions
How can we make industry reduce CO2 emissions?
tax! Don’t make it free to pollute
- if CO2 production is expensive, they’ll find ways to reduce emissions
list and explain 2 canadian carbon pricing mechanisms
- federal fuel tax (ie pollution price or carbon tax)= applies a tax on the sale of fossil fuels, based on their C content
- Federal baseline and credit system= for industrial facilities: allows to release a baseline amount of emissions per unit of product produced
- ie federal output-based pricing system
A potential solution could be to burn methane to convert it to CO2. Explain how this works
methane is 4x stronger than CO2, so if we burn it, it will turn into CO2 and reduce the amount of CH4 in the atmosphere
- decreases CH4 but increases CO2 (which is less potent, but does this really make sense?)
This is very controversial! Short term solution
The federal sustainable development strategy has goals, targets, and actions. Match the term to the definition of each
a) set out what the federal gov will do to reach the targets
b) aspirational results that reflect Canada’s domestic & international priorities and commitments
c) measurable objectives that contribute to each goal
a) actions
b) goals
c) targets
The federal gov’s efforts are assessed on 4 fronts:
1. _____ GHG emissions
2. _____ to climate change
3. ____ subsidies to fossil fuel
4. _____ clean energy
- reducing
- adapting
- eliminating
- promoting
