Geography Revision


Natural Causes of Climate Change

Volcanic Eruptions:

  • Volcanic erupptions produce vast amonts of gasses and ash. These gasses are absorbed by the water droplets in the air, which reflects the sunlight. The large ash clouds also block out the sunligh, causing it to get cooler.  
  • Up to 200,000 people died due to climate change, leading to crop failures, caused by Mount Pinatubo.

The Sunspot Theory: 

  • Black spots seen on the suns surface, indicate that the sun is more active and is emiting more energy, causing it to be warmer
  • Sometimes few black spots can be seen. this means the sun is less active and it not emitting as much heat. 

The Tilt/Wobble of the Earth:

  • If the tilt were to change it will leqad to harsher winters and summers 
  • It takes 41,000 years for the tilit to vary from 24.5 degrees - 22.5 degrees where the normal is 23 degrees.

The Orbit of the Earth:

  • Sometimes the orbit of the earth can change from a circle to an overal over a period of 100,000 years.
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Climate Change Events in Our Past

The Medieval Warm Period (800-1400)

This was a global rise in temperature and was as warm as, and warmer than temperatures today.Scientists believe that the cause of the medieval warm period was due to the increase of solar output from the sun, during the time period.The Medieval warm period occured before the Little Ice age.The production of food during this time was not effected much, however some Crops such as grapes thrived in the warmer conditions. 

The Little Ice Age (1500-1850)

The little ice age mainly occured in the Northan Hemisphere at lasted for a few hundred years. Scientists believe that what started the mini ice age was a series of volcanic activity which lead to the sun rays being blocked out. Melted sea ice also meant tht the oceans where cloder so less heat could be transfer. This is believed to be the reason for why the ice age lasted for so long. The Little Ice Age had a huge impact on many people as the cold conditions lead to crop failures and catlle dying, so people were dying of starvation.

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How Does Climate Change affect Ecosystems

Climate Change can affect ecosystems because when the climate changes it can lead to a change in food change. Here are two examples:

The wipe-out of the dinosaurs had two possible causes, a volcanic erupption in Deccan, India or an asteroid in mexico. The ash produced would have resulted in the sunlight being blocked and the cold weather would have meant that vegetation wouldn't have been able to grow. Because of this food chains would have colasped. 

The extinction of the Megafauna. As the climate change both humans and animals were forced to migrate to other places. Some of the animals were unable to find the right food/plants to eat and consequently did not survive, again this lead to disruption of the food chains. 

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Global Warming

Greenhouse Effect:  :) :) :) :) 

This is where a layer of natural gasses which have been created naturally are surrounding the earth and trapping some of the suns heat energy. Without this natural layer of gas the world would be between -16''c and -30''c colder. Without this we would be unable to grow any crops and it would be very hard to survive.

Enhanced Greenhouse Effect:   :( :( :( :( 

this is where human activities are producing more greenhouse gases such as carbon dioxide which polute the atmosphere.this creates alomost like another layer around the world which means that even moe of the suns heat energy is trapped between the layers of gas which cause Gobal Warming. 

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How to Lower Carbon Emissions

  • Recycle- This reduces the amount of waste that goes to landfill which means less carbon dioxide is emitted during decomposing
  • Save Electricity- Turning off the lights when they are not needed reduces the amount of electricity used so less carbon dioxide
  • Walking- walking means you do not burn fossil fuels when you are driving therefore less carbon dioxide
  • Desposing of Appliances- desposing of appliances properly will ensure they wont produce CFC's which contributes to global warming
  • Alternative power source- using these means you do not have burn fossil fuels in order to create electricity
  • Only use Heating when Nessersery- this saves a lot of energy and less fossil fuels have to be burnt, which produces carbon dioxide.  
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