Providing a moderate, livable climate<span />
Answer:
Democratic Republican or Democracy
Explanation:
One of the main causes was the rise of the Nazi party in Germany. Other considerable causes could be issues from past wars such as WW1. The effects were from the Cold War. There was a lot to break down. Some historians did tons of work to bring you and I this knowledge that's for sure.
Hope this is the answer you were looking for and that it helps. :)
Answer:
had to complete 5 years of continuous residence before receiving ownership of the land
Explanation:
The answer is Human
While the other options are always affecting the ecosystems, humans have a greater affect than all of the above