History .................
It started over the use of icons.The Romans wanted to use icons while the Eastern Orthodox so it as worshipping a false god. This resulted in the Roman Pope excommunicating the Emperor because he banned icons.
The weather affected the building of the Panama Canal quite negatively because the hot, humid weather made the work exhausting. The workers had to take long pauses until it was suitable for them to work again, because it was scorching hot in Panama so that no work could be done. This greatly slowed the process of building the Panama Canal because the workers didn't have the required conditions under which to work properly.