P1: Climate Change Flashcards
What is climate change
The long term change in the earth’s climate. This is especially a change due to an increase in the average atmospheric temperature. Our atmosphere is an envelope of gases surrounding our planet. The earths average surface air temperature has risen by 1 degree centigrade over the last 100 years.
What is the Quaternary Period
Quaternary period - last 2.6 million years ago.
Holocene epock - last 12,000 years since end of last age.
Pleistocene epock - 2.6 mil to 12,000 years ago.
Holocene epock = 0.06% of earths geological time.
Main events in the Quaternary Period
Temperatures have fluctuated a lot
Modern Humans have evolved
Many large mammalian species became extinct
What are Interglacial periods
Periods of warmer than the average
What are the glacial periods
Cold ‘spikes a point below average.
Global Long Term Climate History
cools down slowly
warms up quickly
Interglacial periods = 10000 years
Glacial periods = 100000 years
Natural Causes of climate change
Suns Spots
The earths tilt
Volcanic Eruptions
How Volcanic activity causes climate change
eruptions produce ash and sulphur dioxide.
these rise and cause layers to block the sunlight.
Sulphur dioxide is converted to sulphuric acid which causes droplets which reflect sunlight.
Lowers temp of years
How Solar Activity causes climate change
Sunspots are dark patches on the sun which are caused by magnetic activity inside the sun.
They cause extra solar energy to be sent to the earth.
Orbital Changes
Eccentricity- more variations in the amount of sunlight when we have an elongated orbit.
100,000 year cycle.
Obliquity - Tilt varies between 22.2-24.5 degrees. The < the tilt angle is the more energy the poles receive.
91,000 year cycle.
Precession - A change in the wobble in the orientation of the earth. Earth’s axis affects the relationship between earth’s tilt and eccentricity . 26000 year cycle.
Enhanced Greenhouse effect
Heat from the sun goes into the atmosphere.
Some is reflected back into space some is trapped by greenhouse gases like co2.
Human activity produces more greenhouse gases so more heat is trapped.
The earth gets warmer over time
Human activity increasing levels of GHG in the atmosphere
Burning Fossil Fuels - Burning releases CO2. e.g. coal, oil, natural gases.
Deforestation - Trees can store CO2 but when chopped down they release their store of carbon.
Agriculture - Humans eat more and more so more land is needed for farming.
e.g. Rice production, rasising of live stock - methane.
Greenhouses gases- Sources,%, Warming Power compared to CO2
CO2 - cars,fossil fuels, power stations, deforestation, burning wood. 60%.
CH4 - rice farming, livestock, decaying organic matter. 20%. 21X more dangerous CO2
N2O- sewage treatment, power stations, fertilisers, car exhausts. 15%,300Xmore dangerous CO2.
Global effects of climate change
-Sea level rise- threatens low lying areas.
-Desertification
-Changing ecosystems habitats
-Increased risk of natural hazard
-Increase in extreme weather
-Higher global temps changes
-Spread of heat related diseases
-Glaciers and Ice capss melting
How to manage Climate Change- Alternative energy production
Using renewable energy resources reducing volume of greenhouse gases contributing to climate change
Adv - wont run out, wont have any maintenance requirements, saves money.
Disadv - High upfront cost, low storage capabilities, low efficiency.
Sonoran Solar Project (USA) - produces 260MW of energy. Successful due to high amount of sunlight.
