Ehh, from what I can tell based on reading through the summaries he provides on the later episodes of that series, he appears to be advocating for Anarcho-primitivism, even going so far as to say cities, and even modern medical care and medicine are a part of 'modernity', and thus unsustainable. He is not far off from a doomer, but instead is spinning it as 'letting go' and mentally accepting that we'll collapse into a more primitive state, which he sees as more in-line with positive ecological practices and ultimately a good thing. Some of his language even comes off a bit cult-y, IMHO.

I think there definitely needs to be severe economic degrowth, an end to capitalism, and a heavy focus on regenerating our natural environment and the species that live within it, but we absolutely do not need to have some mass die-off event to have a sustainable planet, we just have to stop the practices that are killing it.