Climate & Change Flashcards
What are the natural causes of climate change?
- Solar Output
- Volcanic Eruptions
- The Milankovitch Mechanism
- Orbital Geometry
What is meant by Solar Output?
The amount of energy given off by the sun.
- Sun is more active in last 60 years.
- Sunspots: patches on the sun which release more energy.
What is meant by Orbital Geometry?
The way the Earth orbits the Sun.
- Circle - Elipse: Earth was 5-6 degrees colder.
- Within 100 years, Earth goes from circle to oval.
- Circular Orbits result in cold, glacial periods.
- Eliptical Orbits result in warmer periods.
What is meant by Volanic Eruptions/ Catastrophic Events?
The idea that volcanos help change temperature. They also produce greenhouse gas.
- 1991 eruption of Mount Pinatubo lowered global temp by 0.5’C.
- 1783, Mt Laki released so much ash that it blocked the sun.
What is meant by the Axis Theory?
The Earth’s tilt affects the amount of the suns energy reaching different parts of Earth.
What is meant by ‘Happy Earth’?
Before humans have inpact
What is meant by ‘Sad Earth’?
Humans having impact
NATURAL CAUSES
What is the Eruption Theory?
- Volcanoes release CO2 and S02
- Causes greenhouse effect
- Can affect the planet for weeks, years etc depending on the size
- Cause cause or end ice age or alter temperatures by 0-2’C
NATURAL CAUSES
What is the Oribital Theory - Circle to Ellipse
- Orbit changes from circular to elliptical orbit
- Takes 100,000 years to complete full circle
- Global temperatures increase when earth is closer to sun and reduce when further away
NATURAL CAUSES
What is meant by Meteorites?
- Have potential to cause catastrophic changes to earth’s climate
- Impact creates cloud of dust, smoke and ash to be released into atmosphere which can block out sun
- Can cause or end ice age
NATURAL CAUSES
What is meant by Orbital Theory - Axis Tilt
- Angle of earth’s tilt can get larger/ smaller
- 41,000 years for full cycle
- Area’s on earth can experience greater climatic extremes so are pointed towards/ further away from sun
NATURAL CAUSES
What is meant by Changes in Solar Output?
- Sun works on 11 year cycles of heightened/ lowered activity
- More solar radiation can be released to earth resulting in changes to earth’s climate
NATURAL CAUSES
What is meant by Orbital Theory - Wobble?
- earth wobbles on axis
- 26,000 years for full cycle
- Area’s on earth can experience greater climatic extremes as pointed towards/ further from sun
HUMAN CAUSES
Main focus of attention is on?
Rising levels of C02 and methane caused by human activity
Source of Carbon Dioxide?
- Burning fossil fuels (coal, oil, and gas)
- Deforestation
- Burning of trees
Carbon Dioxide warming power compared to CO2?
1
Carbon Dioxide % increase since 1850?
Increased by 30%
Source of Methane?
- Gas pipeline leaks
- Farming rice in paddy fields
- Cattle farming
Methane warming power compared to CO2?
21x more powerful than carbon dioxide
Methane % increase since 1850?
Increased by 250%
How much % of global methane emissions come from livestock?
15-20%
What 2 things on a local scale have contributed to climate change?
- Domestic Energy Use
- Car Ownership
Which Milankovitch cycle takes 41,000 years?
Orbital Theory - Axis Tilt
Which Milankovitch cycle takes 26,000 years?
Orbital Theory - Wobble
Which Milankovitch cycle takes 100,000 years?
Orbital Theory - Circle to Ellipse
How many methane emissions come from livestock?
15-20%
What are the three impacts (GLOBAL)?
- Food Production
- Coral Reefs
- Sea Level Rise
Impacts on Food Production?
- Califonia’s weat and maize yield to drop 10-30%
- W Australia 15% drop in annual rainfall since 1970’s = fall in production of agriculture
Impacts on Coral Reefs?
- Warmer waters = bleaching
- Economic impacts on locals as fish and bird numbers decline
- Food chain is disrupted by disappearance of soft corals
Impacts on Sea Level Rise?
BANGLADESH
- 80% of fertile land is under 10m above sea level
- Extreme floods spread over 60% of country
- 65 mill live in high risk flood zones
- huge impact on economy which is reliant on agriculture
What are the two climate change debates?
Humans Are To Blame vs It’s All Natural
Act Now vs Do Nothing
