Climate & Change:
Climate in the past:
What caused climate change in the past? After 3/11/2015, before 10/11/2015.
In the past, climate change was caused by natural causes.These were the eruption theory, asteroid collisions, thesunspot theory and the orbital theory.
Eruptions would produce lots of ash and gas, if they went very high, they would be spread around the earth by the wind and block the sun, making the earth cooler.
Every 500,000 years, a 1km sized asteroid strikes the Earth. This would blast ash and rock into the atmosphere and cool the earth for 5-10 years.
Black dots on the sun (sunspots) are actually magnetic storms. When there are more sunspots, the Earth is warmer because more energy is coming towards it.
There are 3 ways that the earth's orbit changes. It can be circular or eliptical, this takes 100,000 years. When the Earth is closer to the sun, it is warmer. It takes 41,000 years for trhe Earth's axis to tilt and straighten. When a country is tilted away from the sun, is is cooler and vice versa. It could also wobble, this takes 26,000 years. This affects which hemisphere faces the sun at different times of year.
The Little Ice Age:
Socail and environmental impacts:
How climate change caused the extinction of the megafauna:
Mass extinction is when a number of species are wiped out at the same time.
There are 6 ways the climate change caused the extinction of the megefauna:
1) As the last major ice age ended, the temperature warmed by 6 degrees in 1000 years (quickly).
2) So, many megafauna had to migrate.
3) There wasn't enough flora there to support the herbivores, so the megafuana had no prey.
4) They could also have been weaker due to climate change anyway.
5) Humans had also migrated to the same places and hunted the megafuana.
6) Humans also hunted the herbivores, so the megafuana had no prey.
The enhanced greenhouse effect:
In the future:
Case study of a developing country(Egypt):
Why it is vunerable to climate change:
As it gets under 10mm water per year.
Depends on the Nile…