Defining a discrete "boundary" seems misleading, since most of these things have linearly worse effects as you do more of them, there's no bright red sharp line. Eg. climate change is obviously bad, but you can't really point to a specific temperature as a "boundary" - 2C of warming is worse than 1.5C, 3C is worse than 2C, 4C is worse than 3C, and so on.
I didn't recognize the term "novel entities" - it seems to refer to new industrial chemicals, plastics, etc. developed by humans that don't exist in nature. The graphic is drawing on a paper which says people are developing and releasing these chemicals without enough safety testing. That's bad, sure. But how could you say when this has crossed a "boundary" - at a million tons of release? Ten million tons? Of which chemicals? Any chemicals? The paper is very fuzzy, and basically just waves its hands and says:
"We define and apply three criteria for assessment of the suitability of control variables for the boundary: feasibility, relevance, and comprehensiveness. We propose several complementary control variables to capture the complexity of this boundary, while acknowledging major data limitations. We conclude that humanity is currently operating outside the planetary boundary based on the weight-of-evidence for several of these control variables."
Again, sure, obviously pollution is bad, but this doesn't meaningfully define what a "boundary" would be, or what the consequences of crossing it are.
https://pubs.acs.org/doi/10.1021/acs.est.1c04158#
I didn't recognize the term "novel entities" - it seems to refer to new industrial chemicals, plastics, etc. developed by humans that don't exist in nature. The graphic is drawing on a paper which says people are developing and releasing these chemicals without enough safety testing. That's bad, sure. But how could you say when this has crossed a "boundary" - at a million tons of release? Ten million tons? Of which chemicals? Any chemicals? The paper is very fuzzy, and basically just waves its hands and says:
"We define and apply three criteria for assessment of the suitability of control variables for the boundary: feasibility, relevance, and comprehensiveness. We propose several complementary control variables to capture the complexity of this boundary, while acknowledging major data limitations. We conclude that humanity is currently operating outside the planetary boundary based on the weight-of-evidence for several of these control variables."
Again, sure, obviously pollution is bad, but this doesn't meaningfully define what a "boundary" would be, or what the consequences of crossing it are.
https://pubs.acs.org/doi/10.1021/acs.est.1c04158#