GLOBAL WARMING AND CLIMATE CHANGE | CD1
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CLIMATE
what has happened in the past to predict the future
generalised statements
what is normal and expected
based on cycles
WEATHER
what is happening right now or in the near future
measured and observed at a specific time
THE 6 VITAL SIGNS
surface temperature (land and sea)
atmospheric CO2 concentration (carbon footprint)
forest area
land ice area & volume
arctic ice minimum area & volume
sea level rise
V1: GLOBAL AVERAGE SURFACE TEMPERATURE
average global temperature from 1951-1980: 14C
average global temperature from 2009-2014: 14.68C
.68% increase
GREENHOUSE GAS EFFECT
some sunlight that hits the Earth is reflected, some becomes heat
CO2 & other gases in the atmosphere trap the heat, keeping the Earth warm
BLANKET ANALOGY: CO2 & other gases are the blanket keeping the Earth warm, the blanket is getting heavier with more gases being released
6 GREENHOUSE GASES
CO2
H2O (67% of total greenhouse gas effect)
Methane (CH4)
CFC’s (chlorofluorocarbons)
Ozone (O3, reflects UV rays)
Sulphates & nitrates (SOx & NOx compounds from burning fuels)
V2: ATMOSPHERIC CO2 CONCENTRATION
KEELING’S CURVE
graph of the accumulation of atmospheric CO2 based on measurements taken at Mauna Loa, Hawaii
Mauna Loa: remote, unaffected by industrial activity
started in 1958
CO2 reading in October 11, 2015: 398.02 ppm
atmospheric CO2 is rising, but goes up and down every year
increase of CO2 levels is increasing
rise in CO2 concentration is growing in pace, not linear
NECESSITIES TO LIVE
AEROBIC RESPIRATION
primary energy production pathway
sugar + O2 → CO2 + H2O + energy
PHOTOSYNTHESIS
primary food & oxygen source
process that absorbs solar energy, CO2 & water vapour
CO2 + H2O + energy → sugar + O2
CO2
CO2 ↑ = temperature ↑
is not returning to baseline = Earth can’t keep up with our carbon consumption and can’t clean the atmosphere fast enough
CURVE GOING UP AND DOWN?
In spring and summer, plants begin to bloom, scrubbing the atmosphere of CO2 & causing the CO2 concentration to go down with photosynthesis
water & CO2 combine in a synthesis reaction to form carbonic acid
H2O(l) + CO2(g) → H2CO3(aq)
atmospheric CO2 is at 400 ppm
causes oceans to become more acidic (30% more acidic, down 0.3 pH points)
CORAL REEFS AND ACIDIC WATER
coral reefs experience:
weakened calcium carbonate structures, leading to slower growth, reduced resilience, and increased vulnerability to erosion and damage
V3: FOREST LAND AREA
DEFORESTATION
when trees are destroyed, the carbon stored in them are released back into the atmosphere as CO2
deforestation = less trees = less plants photosynthesising = more CO2, less oxygen
STATS
2000 to 2012: 2.3 million km2 of forest lost (3.4x the size of Saskatchewan)
AMAZON RAINFOREST
loses more than 20 000km2 of forest area per year
although decreasing through increased awareness
cleared for agricultural land, soybean crops
INDONESIAN RAINFOREST
loses more than 10 000km2 of forest area per year
increasing over 1000km2 per year
V4: ARCTIC SEA ICE MINIMUM EXTENT
the area of ocean where at least 15 percent of the surface is frozen
all excess atmospheric heat is being absorbed by arctic ice and water
causing it to melt
ice absorbs energy/heat to melt
since 1979, 50% of arctic ice has been lost
remaining 40% is thinner & melts easier
transportation of goods by boat through the arctic made possible by technology, innovation, and climate change
V5: LAND ICE AREA & VOLUME
258 billion metric tonnes of ice lost from Greenland Ice Shelf
147 billion metric tonnes of ice lost from Antarctica
MOULINS
conduits that funnel the meltwater runoff from the ice surface each summer
lead to faster sliding of the ice sheet
acts as a lubricant at the base of the glacier, allowing the glacier to flow more easily, which enhanced melting further
V6: SEA LEVEL
caused by water from melting ice sheets and glaciers & the expansion of warming seawater
400 billion tonnes of ice goes into the ocean
causes sea levels to rise
since 1997, sea level rose 60.12mm
if all Greenland ice melted, sea levels would rise 24ft
if all ice melted, sea levels would rise 216ft
BIOGEOCHEMICAL CYCLES
CARBON CYCLE
WAYS CARBON ENTERS THE ATMOSPHERE
exhalation
burning fossil fuels
plant decay
fires
PHOTOSYNTHESIS
process that absorbs CO2 from the atmosphere
turns CO2 into sugars
PLANTS
perform photosynthesis
use solar energy to combine CO2 with the Hydrogen & Oxygen from H2O to create sugars
DECOMPOSERS
fungi, bacteria, invertebrates, etc
break down dead organisms & waste into smaller components & to create new compounds
without decomposition,
nitrogen in dead organisms would not be released
nitrogen taken from the soil would not get replaced
plant growth would decrease
CARBON SINKS
long-term storage carbon from some organisms is kept in
coal, soil, limestone, etc = fossil fuels
used as energy sources, for agriculture, etc
by using these carbon sinks, we are:
releasing the stored carbon into the atmosphere
releasing the carbon stores faster than they can be
replenished by nature
balance of carbon has been thrown off by human use of the fossil fuels
WAYS CO2 CONCENTRATION IS INCREASING THROUGH HUMAN ACTIVITY
deforestation, pollution
increases CO2 concentration → increasing temperatures → harming wildlife → less photosynthesis → increases CO2 concentration
NITROGEN CYCLE
WAYS NITROGEN GAS IS REMOVED FROM THE ATMOSPHERE
nitrogen fixation by nitrogen-fixing bacteria in the soil and in the root nodules of legumes
4 TYPES OF BACTERIA INVOLVED IN THE N2 CYCLE
nitrogen-fixing bacteria
decomposing bacteria
nitrifying bacteria
denitrifying bacteria
AMMONIFICATION
process where animal wastes, urine & dead organisms turn into nitrogen containing compounds
NITROGEN-FIXING BACTERIA
transform atmospheric nitrogen into fixed nitrogen that is usable by plants
DECOMPOSING BACTERIA
decomposes organisms
NITRIFYING BACTERIA
converts ammonia into nitrites and then into nitrates
DENITRIFYING BACTERIA
convert nitrates back to atmospheric nitrogen
WATER CYCLE
LARGEST WATER RESERVOIRS
oceans
WATER CONVERTED TO VAPOUR
evaporation
transpiration
WATER RETURNING TO THE OCEANS FROM THE LAND
surface run-off
precipitation that does not soak into the soil but instead moves on land toward streams
groundwater flow
water that exists underground that is discharged into a stream
EXAMPLES OF PRECIPITATION
rain, sleet, snow
POLLUTED AIR AFFECTING WATER
through condensation, the polluted air can be brought down to and pollute rivers, streams, lakes & oceans
CLOSED SYSTEM
if one place with water is polluted, the whole water system can get polluted
ex: ground is polluted → surface run-off will pollute the water → polluted water evaporates → pollutes the air
HOW DOES PRECIPITATION & RUN-OFF CONTRIBUTE TO POLLUTION
PRECIPITATION
pollutes water with air pollutants
RUN-OFF
carries ground pollutants to water
PLANTING OF LEGUMINOUS PLANTS
farmers leave old roots in the soil & plant leguminous plants back into the soil
legumes have bacteria that convert nitrogen into a form plants can use
boosts nitrogen levels
increased soil fertility
lowers environmental impact of farming
lowers use of fertilisers
LONG ANSWER QUESTION
3 VITAL SIGNS PROVING GLOBAL WARMING (1 BEING CO2)
ATMOSPHERIC CO2 CONCENTRATION
pre-industrial revolution, CO2 concentrations were at 280 ppm
now: 420 ppm
CO2 is a significant greenhouse gas
increased concentration enhances the natural greenhouse effect
traps more heat in the Earth's atmosphere
mostly caused by the burning of fossil fuels, ex: coal, oil, and natural gas, and deforestation
FOREST LAND AREA
trees are carbon sinks that absorb CO2 from the atmosphere
reduction in forested areas diminishes the Earth's capacity to sequester CO2
leading to higher atmospheric CO2 levels
feedback loop where increased CO2 levels contribute to global warming, which in turn can affect forest health and productivity
climate change affects trees with:
increased frequency and intensity of wildfires, pest infestations, and droughts
ARCTIC MINIMUM EXTENT
each summer, the Arctic sea ice reaches its lowest extent
correlates closely with the rise in global temperatures due to increased greenhouse gas emissions
higher temperatures = more heat for ice to absorb = more ice melting and more ice melting faster
direct consequence of warming temperatures, which cause the ice to melt more extensively and earlier
less ice = less sunlight is reflected back into space = more is absorbed by the darker ocean waters = warming waters and planet
consistent and accelerating decline in Arctic sea ice cannot be explained by natural variability
it is caused by human activity
HUMAN ACTIVITIES CAUSING CLIMATE CHANGE & THEIR EFFECTS
BURNING FOSSIL FUELS
EXAMPLES: burning coal, oil, and natural gas for electricity generation, transportation, and industrial processes
EFFECTS
emits greenhouse gases
primary source of CO2 emissions
contributes significantly to the greenhouse gas effect
creates a ‘bigger’ and ‘heavier’ blanket over the Earth
increased concentration of CO2 and other greenhouse gases traps more heat in the atmosphere, leading to hotter temperatures
DEFORESTATION
EXAMPLES: clearing forests for agriculture, logging, and urban development
EFFECTS
less trees = less things photosynthesising & absorbing CO2 = more CO2 in atmosphere
destruction of habitats, endangering biodiversity and disrupting ecosystems
INDUSTRIAL AGRICULTURE
EXAMPLES: large-scale farming practices that include the use of synthetic fertilizers, pesticides, and extensive irrigation
EFFECTS
emits a lot methane gases from livestock farming, particularly cattle
emits nitrous oxide from the use of synthetic fertilizers
intensive agriculture leads to soil degradation, deforestation, and loss of biodiversity
reduces the land's capacity to absorb CO2 and maintain ecological balance