Water shortage, domestic waste, coastal erosion
The sky is blue because blue light is scattered in all directions by the tiny molecules of air in Earth's atmosphere. Blue is scattered more than other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time.
One simple and easy way that scientists can accurately date fossils found is through the ground levels. When you take a big chunk out of the earth, you can see the changes in the texture in the "ground" Each "layer" represents a set of years. And as you get further and further into the ground, fossils become older and older.
The only country that boarders both Israel and Libya is Egypt