These revision cards will be reviewing:
- Past Climate Change - The Little Ice Age
- Natural Causes of Climate Change
- Present and Future Climate Change
- The UK Climate - Environmental and Economic Impacts
- The Effects of Climate Change
- The Bangladesh Climate - Environmental and Economic Impacts
Ice Age - An extended period of time when its cold.
Quaternary - The last 2.6 million years of geological time.
Glacial Period - A period of time lasting between 80,000 to 100,000 years.
Interglacial Period - A warm period of time lasting between 10,000 to 15,000 years.
Past Climate Change - The Little Ice Age
The little ice age was a colder period in northern Europe starting in the 15th century and lasting to the mid 19th century.
It has various negative impacts on people:
Crops did not grow well which meant people had to go hungry because there were less productivity and food.
The winters were very cold and the summers were very short.
The little ice age was most likely to be caused by natural changes and not humans because there were not enough people or industry to cause it.
It could have been caused by:
- Fewer sunspots
- Volcanic ash in the atmosphere
- Orbital Changes
- Asteroids hitting the Earth
Looking at tree rings in old trees can tell us what the climate was like. The thinner the rings in the trees, the colder the years were.
During the little ice age, Megafauna (big animals) had evolved during the Ice Age.
These animals were weighing over 40kg, such as wooly mammoths, giant beavers and sabre-toothed tigers.
One the ice age has finished, the temperatures rose by 5 degrees celcius in 10,000 years.
Due to this temperature rise, the megafauna couldn't adapt to the change of a warmer climate and then these animals became extinct.
Also, humans could be a cause to their extinction due to the hunting of Megafauna.
Present and Future Climate Change
Most people agree that humans are causing climate change through the production of greenhouse gases.
The rise in greenhouse gases, such as carbon dioxide and methane, matches the start of the Industrial Revolution.
Animals, such as cows, contribute to the methane released in the atmosphere due to their waste.
Current levels of carbon dioxide are thought to be at their highest levels for at least 650,000 years.
Current levels of methane are thought to be at their highest for at least 900,000 years.
Methane is 21 times more potent than carbon dioxide.
As country develops, more greenhouse gases are produced and released into the atmosphere.
More carbon dioxide is produced because:
- There is more industry
- More energy is needed so more fossil fuels are burned
- Transport increases so more vehicles ont he road consuming petrol and diesel
The Greenhouse Effect
1. Most of the radiation is absorbed by the Earth's surface and warms it.
2. Some solar radiaton is reflected by the Earth and the atmosphere.
3. Some of the infrared radiation passes through the atmosphere. Some is absorbed and re-emitted in all directions by greenhouse gas molecules. The effect of this is to warm the Earth's surface and the lower atmosphere.
4. Infrared radiation is emitted by the Earth's surface.
The UK Climate
The climate of the UK is mild and wet - temperature maritime.
Several factors impact on the UK's climate:
- Latitude affects how much Sun the UK gets and how strong it is during different seasons.
- The North Atlantic current keeps the UK warmer than other places of the same latitude.
- Air masses bring weather conditions with them. The UK is affected by 5 air masses.
- The prevailing winds from the Atlantic Ocean in the South West. They pick up moisture from the sea and often bring rain to the UK.
Possible changes to the UK's climate include:
- Average temperature rise
- Less predictable rainfall patterns with drier summers
- Changing seasons - possibly longer summers and more extreme cold in winter
These changes will happen because:
- The North Atlantic current is likely to move which will probably reduce sea temperatues and bring less rainfall
- More air masses will come from the north, bringing more storms and maybe more extreme cold in the winters.
- The paths of depressions, which bring rain, may be altered by these changes in air masses and ocean currents
The UK Climate - Environmental and Economic Impact
- Loss of coastal land and increased erosion due to sea level rise.
- More severe storms and longer summer droughts.
- Changes to fishing industries if fish species move to different waters.
- Eco-system change could mean some plant and animal species move into new areas and new invasive species emerge.
- Warmer temperatures could encourage diseases such as malaria.
- Damage to cities from flooding would be expensive and extremely disruptive.
- Farmers can grow different crops and enjoy longer growing seasons if warmer weather occurs.
- People would spend more holidays in the UK then goin abroad if there were hotter summers.
- Cost of protecting places from flooding will be expensive.
Predicting the effects of Climate Change
If carbon dioxide concentrations go over 550 parts per million, the predictions are that:
- Global temperature rises will be 6 degrees celcius more
- Millions of people would lose their home due to sea level rises
- Changes to world weather patterns would cause extreme weather such as droughts and storms, leading to famines and disasters.
- Animal and plant species would not be able to adapt fast enough to the changes, meaning that they would eventually die out.
If carbon dioxide concentrations stay under 550 part per million, the predictions are that:
- Global temperature rises will not go above 2 degrees celcius.
- Sea level might rise up to 1 metre, causing coastal flooding.
- More storms and hurricanes will occur
- Some species may be wiped out and others would shift to new zones.
The Bangladesh Climate
Banglaseah is a low lying country that is already suffering problems from coastal and river flooding which is not helped by its very large and very poor population. This makes the area extremely vulnerbale to climate change. Climate change will affect Bangladesh both environmentally and economically.
The environmental impacts are:
- There is already severe river flooding, which would become worse from heavier rainfall and sea level rise.
- Tropical storms could become more of a common occurrence, and possibly do more destruction if it were to move further inland.
- The dry season is already getting longer and this could cause more droughts.
The economic impacts are:
- A small rise in sea levels could massively impact upon Bangladesh's farmland and agricultural output.
- More river flooding could cause damage to peoples homes and more disruption to lives and the economy.
- Shrimp farming, is a very important but rising sea temperatures may damage this form of aquaculture.
- Increased flooding will increase the spread of water-borne diseases.