In a shiur which my Rov gives early Sunday AMs on Rav Dessler’s writings), he told us that it was not that the people made fun of Noach because they didn’t believe a flood was coming. On the contrary, the DID believe, and therefor built strong homes and fortresses to protect themselves. But they laughed at that foolish Noach spending 120 years building an Ark out of the flimsiest wood and a little tar, thinking it could possibly withstand a torrential downpour. That’s where the derision lay. And boy were they ever shocked when his flimsy vessel held his family and all those thousands of species of animals safe from the Mabul, as their own reinforced “safe houses” broke apart and they all drowned.
It is very interesting to me, as my rov pointed out in R’ Dessler’s teachings, that Noach who was called “ish tzaddik” was not a baal chessed UNTIL he was forced to do daily chessed in caring for all the animals. A tzaddik will give tzedaka to whomever ask him. A baal chessed will go out looking for people to whom he can give tzedaka. That’s why Noach was not in the same league as Avraham Avinu, the paradigm of chessed. It also explains why Noach actually made a tikkun Olam through the chessed of taking care of the animals. His act was one of giving. The “chamas” (which is quoted as the ultimate straw that broke the camel’s back, resulting in Hashem’s decisiion to cleanse the world through the Mabul), were people’s repeated acts of rationalized “gezel,” of stealing from each other. That taking, was why the world needed to be destroyed. It merited being renewed through Noach’s act of giving on a daily all-day basis.