Changing Climates Flashcards
What do we call historical warm periods?
Interglacial periods
What do we call historical cold periods?
Glacial periods
How does climate vary over history?
Mostly glacial with a few interglacial periods. In the last 2,000 years it has been rising and is now the highest it has ever been.
What is the Milankovic Cycle?
The cycle in which the Earth’s orbit changes shape slightly over 100,000 years so sunlight amounts vary. This can contribute to climate change.
What are the natural causes of climate change?
- Milankovic cycle
- Earth wobbling on its axis varies how much sunlight we get
- Ash from volcanic eruptions can stop the sun’s rays from reaching the Earth
- Asteroid collisions block out the sun
- Asteroids collide with Earth and release Carbon Dioxide
- Sunspots give particularly high amounts of heat
How are humans accelerating the greenhouse effect?
By burning fossil fuels which release greenhouse gases. These gases culminate in the atmosphere and prevent heat radiated from the Earth to escape.
What are ecosystems?
Systems which involve plants, animals and the physical environment working together to survive.
What happens if you change one part of an ecosystem?
The whole system is affected
What are the two possible things that caused the dinosaurs to become extinct?
- A meteor strike in Mexico
* A million-year volcanic eruption in India
Regardless of what the instigator was, how did the dinosaurs become extinct?
- Layer of ash released into stratosphere
- Sun blocked out
- Plants can’t survive without sunlight so die off
- Herbivore dinosaurs die without a food source
- Carnivore dinosaurs die without a food source
What happened to the Megafauna?
They started to move north about 10,000 years ago as the climate rose. However, they couldn’t find their usual food which broke the ecosystems of the area and so the megafauna started to die. Humans also started to move in to similar areas and hunted the megafauna.
When was the Little Ice Age?
Between the 15th and 19th centuries
What do scientists think caused the Little Ice Age?
A drop in sun spots and a rise in volcanic activity
What were the negative effects of the Little Ice Age?
- Crops failed leading to food shortages
* Long winters and short summers
What were the positive aspects of the Little Ice Age?
- Frost fairs held on the Thames when it froze over
* We could grow new crops - i.e. potatoes
What term is used to describe the UK climate? Why?
Temperate Maritime. This means we get warm winds from the south-west.
What else warms the UK aside from winds from the south-west?
The North Atlantic Drift
What does the polar front do?
- Determines what air masses we get
* Moves with the seasons
What are the three possible climates the UK could have in the future?
- Warmer climate
- Cooler climate
- Wilder climate
Describe a Warner climate
- Polar front will move north
- Mediterranean summers
- Higher drought chance
What could the pros of a warmer UK climate be?
- Lower heating costs
- More tourists
- Fewer cold related deaths
- New crops
- More land suitable for farming
What could the cons of a warmer UK climate be?
- More water shortages
- Increase in heat stroke and skin cancer
- Melt roads and buckle railroads
- Some wildlife could die out
Describe a cooler climate
- Polar front moves south
- Increased flooding
- Colder summer
What would a wilder climate include?
- Heatwaves
- Flooding
- Storms
What would the economic impacts of a wilder climate be?
- Higher insurance rates
* Flood proofing buildings would cost a lot
What are Egypt’s greenhouse emissions like?
They are very low
What is a consequence of Egypt having a lot of uninhabitable desert?
99% of the population live on 5% of the land
What could the impacts of climate change be on Egypt?
- Tenperature rises of 8 degrees - twice global average
- less and unreliable rainfall
- Spread of desert
- Failing crop yields
- Spread of malaria, strokes and skin cancer
- 7 million people would have to leave
Describe Egypt’s water war.
Water is very scarce in Egypt because rainfall that feeds the Nile is largely caught upstream. As countries upstream such as Uganda and Sudan build dams, Egypt gets less and less water leading to conflict.
