This website could help you http://www.weather.gov/cle/Seasons
A-through an optimistic viewpoint.
One way is that the sun is heating up the world causing droughts and causing the water level to rise to cause floods
Answer: Texas and California
A possible cause was a meteorite hit the earth. it caused many organisms to become extinct because it blocked out the Sun so plants couldn't grow and herbivores couldn't eat the plants and carnivores couldn't eat herbivores.