This is such a tired argument. The socialist block was, at least by the 1980s, much more wasteful and destructive to the environment than the capitalist world. I encourage you to search for videos like "1980s krakow winter" or "Elbe river GDR" to see a few examples. Then for comparison research when capitalist countries passed their various environmental protection laws.

More than that, it's easy to make abstract statements like "we need to slow down", but how do you imagine that could be done? Who decides which sectors need to be frozen and how do we make sure we don't accidentally starve millions of Africans while doing it (look up food self-sufficiency numbers)?