Download 15_06_Human Effects on Ecosystem

The Effect of Humans
On Ecosystems
and Biological Cycles
Changes to the Atmosphere
 The atm is a greenhouse
 Normal atm composition maintains global
temperature
 Too much Carbon Dioxide in atm will increase
global temperature.
 Carbon dioxide traps suns rays rather than
reflecting them back into space - global
CO2 Increase Due to
Human Activities
 Carbon dioxide has increased by 30%
since the industrial revolution
 Canadians release 18 000 kg of carbon
dioxide/person/year
 Why?
 Burning fossil fuels (gas, coal, oil) for
energy (factories, homes, workplaces) and
transportation
 Aerosols
 Deforestation
Global Climate Change

Warmer atm influences:
1) Sea levels rise (melting ice
caps and glaciers)
-flooding of low lying areas and
coastal regions
-higher tides; coastline erosion
-salt water can enter wetland
ecosystems (some species may
die out while others flourish)
Global Climate Change
2) Higher Ocean Temperatures
-shift in ocean population
-algae blooms
-decreased fish population, species
may die out
Global Climate Change
3) More Energy in the ATM
-severe weather: storms, tornadoes,
hurricanes
-floods
-droughts (increase in Forrest Fires)
This will impact AGRICULTURE, HUMAN
HEALTH, and PROPERTY.
Hurricane Katrina
BC Forest Fires
Global Climate Change
4) A Shift in Carbon Cycle
-increased photosynthesis
-some plants growing faster
-others may not grow due to higher
temperatures
-may change nature of agricultural
crops (weeds?)
Global Climate Change
5) Human Health:
-increase in viruses and bacteria that
prefer warm climates
e.g. malaria
-respiratory illness due to increased
pollutants in air; swelling due to
heat
Nitrogen Increase Due to
Human Activity
 Sewage plants and crop fertilizers release
nitrous oxides into the atmosphere
 More nitrogen is being added to the
environment than ecosystems can use
 Excess nitrogen in soil increases soil acidity
and damages tree and plant roots
 Eutrophication of lakes when nitrogen
compounds build up due to sewage plant
wastes; increase algae growth
Acid Rain
-caused by burning of fossil fuels
-nitric acid and sulfur dioxide
released
-acidify lakes
-species that cannot tolerate
acidic environment die out
(Maple trees)
-degrades limestone buildings
What Can You Do to Decrease
Greenhouse Gas Emissions?
 Be power smart - unplug, turn off lights
 Walk, bus, carpool
 Fuel efficient vehicles (not SUVs)
 Purchase energy efficient appliances
 Recycle - reusable energy
 Plant trees near your home
A Few Interesting Facts
 If people let their dishes air dry instead of
using the heat setting on their dishwashers,
we could decrease CO2 emissions by 200
pounds/year/household
 Painting houses dark colors in cool climates
and light colors in warm climates decreases
CO2 emissions by 5000 pounds/year/house
How Much Carbon Dioxide
Does Our Class Emit Getting
to School?
 Estimate the distance to school:
 Charleswood: 3.5miles
 Waverly/Lindenwoods: 2.5 miles
 Pembina: 5 miles away
Identify Transportation
Method
Miles/gallon
Pounds
CO2/gallon
Compact car 24
20
Fullsized car
Truck/van
Bus
20
21
22
16
13
8