"Johnny...did you not look at the pictures of the beaches without tourist. The clips of dolphins surfing etc"
Nothing to do with climate change, simply less humans, particularly in boats will mean fish will come in.
I dont thing there were any changines to the climate changing, yes pollution got better and that is certainly something to think about but the lockdown had zilch effect on Nature changing our climate.
We need to live with the fact that the climate changes. Has done for millennia and will continue to do so for Millennia to come. So dont build on flood plains or near cliff edges and adjust crops etc to the prevailing conditions of the time.