See that's the problem of if I can't see it, its not happening. Or worse, if I don't understand it, its not a problem. There are a million things that depend on precise balance and happen in infinitesimal quantities. NO2 happens in the junctions of your synapses in mind numbingly small quantities and lasts as NO2 for only nanoseconds. However, without that happening you cease to function. 1 pound of botulina toxic properly distributed is enough to kill the entire human population several times. You haven't the foggiest clue which species or processes are critical to the continued function of our ecosphere, how can you begin to measure what is or isn't significant without understanding that living things have indirect and profound impacts and implications.
Our planet functions on virtually countless feedback cycles, so when something over here shifts another system over there picks up the slack and tends to recenter the system. Increase the heat, more clouds and earth reflects more sunlight. Up to a point. Once you exceed the normal capacity for the "Global System" to absorb more energy/ CO2/ heavy metals/ plastic... whatever, then old systems breakdown and subtle but significant shifts begin to make themselves evident as fundamental perturbations in the existing system.
The change in carbonate vs carbonic acid in the ocean is telling (and making life for carbonaceous shelled sea life growingly more difficult.) The loss of glaciers and polar marine ice while possibly enhancing navigation, is already having significant impact both in rising sea levels and changes in ocean salinity. In fact a recent report suggests that as much as 40% of the increased sea level and reduced salinity is directly attributable to human enterprises over the last 2 centuries.
CO2 is in fact toxic, but not in the quantities one is likely to see on an earth that isn't in catastrophic environmental meltdown. I don't see such a meltdown happening in my lifetime of that of my grand children's. However there is a potential avalanche of greenhouse gases soon coming where the warming caused by CO2 triggers a sudden explosion of methane from decaying permafrost in the high latitudes and potential release of massive methane ice seeps in the ocean. Its all tied together. Its a little like someone saying I need some wire while driving a truck, and having your passenger go under the dashboard and cut you some. You might get away with that for a little while, but sooner or later something really nasty will happen. Why would anyone, keep cutting. Its silly. There's no need. The only folks who would truly suffer are the incredibly rich executives at companies that sell us our fossil fuel fix (and by the way the warnings of jobs are coming from the folks who I would suggest are far more worried about their golden parachutes and fat campaign contributions.) Let's simply make the move to saner energy sources, by all means nuclear, solar, wind, geothermal, add OTECs, Tidal hydro generation, new hydrogen technologies. Nobody can tell me that it would be more difficult to build a sustainable energy economy than to send a man to the moon 1960. We actually have sufficient technology to resolve our own problem today, all we lack is the leadership and will to implement it.