nuclear plants usually have a significant ecological footprint and it only growths stronger with climate change.
If the rivers they are typically placed at, carry less water, which we can see all over the world to happen, they stress the rivers ecology further and are at risk of needing to be shutdown, or slow cooking the river dead. That in return has consequences for peoples access to usable water, as the intact ecosystem in the water cycle is vital for the quality of water.
So while the current CO2 emissions might be lowest, which also does not account for the change in energy production for the plants creating solar panels or wind turbines, the local impact is much more severe than that of a solar or wind power plant.