ENVS 1000U Study Guide - Winter 2018, Comprehensive Midterm Notes - Water, Solar Irradiance, Soil Erosion
ENVS 1000U
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Lecture 2
What is environmental science?
- It is the knowledge and understanding of how the environment works
- It is a science not an advocacy
- It is interdisciplinary (drawing on many divisive disciplines)
Lecture 10
What is Climate?
- It describes the patterns of atmospheric conditions (such as temperature, moisture content,
precipitation, wind, etc.) across large geographic regions over long periods of time
What is Weather?
- Specific atmospheric conditions over short time periods (hours, days) within small geographic
areas
The sun exerts more influence on the climate because without it the earth would be dark and frozen
The atmosphere exerts more influence on the climate since without tit the Earth's temp. would be
colder
The oceans exert more influence on the climate by shaping the climate through storing/transporting
heat/moisturise
30% of the solar energy is reflected
70% of solar energy is absorbed
What is Climate Change?
- It describes the trend and variations in Earths’ climate (e.g. temperature, precipitation, storm
frequency and weather extremes)
global warming
- It is the increase in the Earth's average temperature. Rapid climate change taking place now
are due to human activity (fossil fuels, combustion, and deforestation)
What is causing global climate change?
- The changes in absorption of Solare radiation (increased absorption= increased warming/
decreased absorption=increased cooling)
What are the factors that affect the absorption of solar radiation?
1. Orbital cycles of Earth: periodic changes in Earth's rotation and orbit around the Sun
(referred to as Milankovitch Cycles)
2. Solar output: drives temperature change on Earth's surface because of variation in solar
flare activity and solar storms
3. Ocean absorption of atmospheric gases: the ocean holds 50 times more carbon than
the atmosphere, and by absorbing CO2 from the atmosphere, the ocean acts as a carbon
sink that maintains stable levels of atmospheric gases
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4. Ocean circulation patterns: worldwide current system in which warmer, fresher water
moves along the surface, and colder, saltier water moved deep beneath the surface. This is
impacted by glacier and polar is melting.
5. Changes in atmospheric gases (especially greenhouse gases): changes in
atmospheric gases that absorb infrared radiation (water vapor, ozone, CO2, NOx,
chlorofluorocarbons) can alter amount of solar radiation absorbed by the Earth's surface.
With more absorption the Earth's surface temperature increases and emits more infrared
radiation that warms lower atmosphere
• CO2 is the most abundant but not the most potent. Methane is the most potent
6. Changes in absorption of solar radiation by Earth. Albedo can alter the amount of
solar radiation absorbed.
Positive forces are the warming effect, the negative forces are the cooling effect
What is the evidence of climate change?
- Direct atmospheric sampling describes the present: CO2 levels in Mauna Load, from 1995 to
2005= 315ppm to 383ppm
- Long-term temp. measurement describes trends: temps. Were cooler in the first half 20th
century then started to increase
- Proxy indicators provide info about the past: proxy evidence (types of indirect evidence)
instead of direct measurements. (evidence from ice cps, ice sheets, glaciers, sediments, plants,
animals, fungi and microorganisms)
• Trapped air bubbles in ice cores.
• For the past 400,000 years temps have followed CO2 levels which has increased
significantly
• Sediment cores preserve pollen grains and other plant remnants
• Tree rings indicate age, wetness of season, droughts and seasonal growth
• Coral reefs provide data on past ocean conditions
What are the Implications of Global Climate Change?
1. Temp. changes will be greatest in arctic
2. Changes in precipitation will vary by region: some will have more precipitation while others
less. More extreme weather (hurricanes). Drought more frequent.
3. World-wide glaciers are melting rapidly: risk of floods as ice dams burst. Albedo Changes: less
reflective surfaces due to ice melting which means more absorption on the ice that didn’t
melt=more melting
4. Rising sea levels are observed in coastal areas: ice melt=increase water flow=oceans expand
due to warming=beach erosion, floods. Sea levels has risen 10 to 20cm over the last century
5. Coastal areas will flood: storm surge=rise in sea level from high tides and winds associated by
storms
6. Ocean waters are becoming more acidic: CO2 levels increase= decrease Ph level (acidic)= coral
bleaching= depriving corals of necessary carbonate ions for structure
7. Climate change exerts ecological impacts: species moving to higher altitudes or latitudes, early
blooming flowers, early hatching od insects
8. Climate change exerts societal impacts in: Agriculture (growing season shortened, more
droughts, decrease crop production), Forestry (increase insect and disease outbreaks, increase
forest fires), Health (heat waves, stress, respiratory ailments, drowning), Economics (widen the
gap between rich and poor)
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
It is the knowledge and understanding of how the environment works. It is interdisciplinary (drawing on many divisive disciplines) It describes the patterns of atmospheric conditions (such as temperature, moisture content, precipitation, wind, etc. ) across large geographic regions over long periods of time. Specific atmospheric conditions over short time periods (hours, days) within small geographic areas. The sun exerts more influence on the climate because without it the earth would be dark and frozen. The atmosphere exerts more influence on the climate since without tit the earth"s temp. would be colder. The oceans exert more influence on the climate by shaping the climate through storing/transporting heat/moisturise. It describes the trend and variations in earths" climate (e. g. temperature, precipitation, storm frequency and weather extremes) global warming. It is the increase in the earth"s average temperature. Rapid climate change taking place now are due to human activity (fossil fuels, combustion, and deforestation)
