Climate change is already making floods more frequent and more intense. As the world warms, the atmosphere can hold more water vapor. That extra moisture leads to more extreme precipitation events, like the heavy rains that cause floods.
At the same time, sea level rise is making coastal flooding worse. As the oceans warm, they expand. That means that even a small storm surge can lead to flooding that was once impossible.
Climate change is also making floods more difficult to recover from. Warmer temperatures mean that floodwaters evaporate more quickly, leaving behind salt and other pollutants. That can damage crops and make it harder to drink the water.
There are steps that we can take to reduce the impact of climate change on floods. For example, we can reduce greenhouse gas emissions to slow the warming of the atmosphere. We can also adapt to the changes that are already happening by building levees and other flood-control infrastructure.
But adaptation will become more difficult as climate change continues. Eventually, we may have to abandon some coastal areas altogether. That would be a devastating loss, but it may be the only way to protect people from the ever-increasing risk of floods.
https://www.scientificamerican.com/article/how-climate-change-is-making-floods-worse/
https://www.nrdc.org/stories/how-climate-change-making-floods-worse
https://www.washingtonpost.com/news/energy-environment/wp/2015/10/05/this-is-how-much-worse-floods-and-droughts-are-getting-because-of-climate-change/