So for example the Soviet Union never had environmental disasters, prison labor and slavery, or its own military-industrial complex?

The Soviet Union collapsed in 1991. So certainly not since then.

I'm a little surprised you didn't pivot to China. But then you might have to ask what they've been up to in the Gobi Desert or with their domestic air pollution or in pursuit of zero-emissions international bulk shipping

In fact China is one of the only countries set to OVERACHIEVE its climate goals by 2030

Obviously bad stuff like that happens.

If we're just running the numbers, we'll consistently find that privatization consistently increases the rate of pollution despite reducing gross productive volumes.

In that sense, capitalism is absolutely responsible for Net Increase In Per Capita Pollution.

It isn't merely that bad things happen. It is that in a private model, the economic benefit of production is given priority over the social cost of ecological degradation. Soviet central planned economies, operating as a holistic body, must account for waste. And while they can have a tolerance of it in pursuit of longer term goals, they cannot ignore ecological costs indefinitely. The Dengist industrial period is a perfect case in point. Although, under Lenin at least, the Russian Soviets gave ecological preservation a priority not known since at least Catherine the Great.

"Capitalism" in the functional sense is an ecological moral hazard. Westward expansion is uniformly recognized as an ecological blight, with a number of very plain incentives to wage war through ecological destruction, most notably during the Indian Wars. And plantation ecology was nearly as bad as its labor practice, with southern tobacco farming rapidly depleting the soil and causing crop failure that even 18th century rural aristocrats couldn't ignore.

These two economic systems are not the same in this regard.