> You do know that the west is continuing to grow while using less and less resources ever year? For a long time GDP followed resource use, now it has been decoupled.

I know some people argue this, but I think this argument misses the point, particularly when it is made rhetorically and not spelled out in detail. I don't think if GDP is coupled to resource usage or not is relevant when we're talking about physical / ecological limits. GDP doesn't measure anything physical, so it isn't a particularly helpful thing to add into the discussion.

What precisely could we mean by GDP decoupling from resource usage?

Suppose the statement "GDP has now decoupled from resource usage" is defined like so: Let g(t) denote GDP and r(t) denote resource usage at some time t. Then by "GDP has decoupled from resource usage" perhaps we mean that the fraction g(t) / r(t) will becomes arbitrarily large (monotonically in t, say) as t increases.

That sounds superficially positive, but then consider, from an environmental perspective, the GDP g(t) quantity is irrelevant -- it measures economic activity in units of human accounting conventions, it doesn't measure any physical quantity about our world --- we need to be able to enforce upper bounds on r(t), resource usage, for key resources, where we express r(t) in terms of physical and environmental limits.

To cherry-pick a working definition of resource consumption, r(t), for a key environmental bottleneck resource, we could approximate r(t) as "consumption of remaining free storage capacity for CO_2-e in the atmosphere to have a 2/3rds chance of limiting global warming to at most +3 degrees C, in gigatons of CO_2-e". That's measurable, has real physical meaning, is a critical factor in the future of our environment, our society & our physical economy, and is still being consumed with no real sign of us all slowing down.

If you look at the trend of CO_2 emissions attributed to the US and Europe, I acknowledge there is a slight downward trend over the past few decades:

https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di...

If we want to pick at the details I might argue that the graph attributes CO_2 emissions to countries like China for polluting economic activity required to produce cheap goods that are consumed in wealthy countries that industrialised earlier, so arguably this way of attributing CO_2 emissions against countries doesn't even fairly account for which countries are capturing the value associated with producing the pollution. You might argue that the manufacturers of exported goods captured a lot of the value, and imported a lot of stuff from other countries to help bootstrap their industry, so my argument that western countries likely are more responsible for CO_2 pollution in recent years than this graph suggests isn't entirely one-sided.

But, leaving that all those blame games aside, the slight declines observed in some countries CO_2 emissions is nowhere near fast enough compared to the remaining capacity left in the our shared global greenhouse-gas-atmospheric-sink definition of remaining resources r(t) . If you squint and look at the trends over a 50 year span for a country like the US, it doesn't look like greenhouse gas emissions have becoming arbitrary small, at a very crude approximation it looks more like that they're constant! US emissions now are similar to what they were in 1970. They need to go negative!