We're on track to reach 1000ppm by the end of the century, if levels continue to rise at their present (accelerating) rate. This is about the threshold where cognitive effects become reliably detectable. However, such levels also bring climate change on such an apocalyptic scale (4.5+ degree temperature rise) that industrial activity could well wind down as society collapses.

This is absolutely not true.

The predicted number is much closer to around 650 ppm, and that's assuming no change.

In reality, things like solar technology have massively gone down in price over the last couple decades, and are only continuing to reduce in price.

We will likely see 2-3 degrees of warming, but no credible scientist is making the predictions that you seem to be making.

I suppose the question is, predicted by whom? And no change in what?

If there is no change in CO2 emission, then yes we might restrict the total damage to 650 ppm. But "no change in CO2 emission" doesn't mean "business as usual", it means a moratorium on all kinds of expanding industrial activity.

Not only are CO2 levels increasing, but CO2 emission rates are increasing. Hell, the first derivative of CO2 emission rate was also increasing until the past couple of years, a minor but happy development that could easily snap back. "Business as usual" means an exponential curve.

Solar powered industry is still a far-off pipe dream. Even if it only takes 30 years to replace all energy sources with sustainable alternative, in 30 years huge damage will have been done. We cannot afford to just shrug and say the problem will just solve itself.

https://www.co2.earth/images/widgets-in-site/climate-interac...

> I suppose the question is, predicted by whom?

As predicted by the scientific consensus and the intergovernmental panel on climate change.

Disagreeing with them on this is no different than being a climate change denier, TBH.

The right thing to do is listen to the opinions of the experts, and this is what the experts believe and is the scientific consensus.

> The predicted number is much closer to around 650 ppm, and that's assuming no change.

Though solar and other non-carbon energy sources are coming down in price, world energy needs are outpacing them. Out CO2 emissions are increasing, not decreasing. I doubt that we'll see 1000 ppm by the turn of the century, but if the "no change" projection is 650 ppm then by simple matter of inference, due to increasing CO2 output, we should be higher than that.

What I am saying is, that we will get to the point where it literally doesn't matter if world energy demand is increasing or not.

Why? Because if solar power and others, continue to go down in price, as they are doing now, then solar ect will be cheaper than coal.

From a purely economic stand point, countries will eventually just stop burning coal, because the alternatives are just flat out cheaper, even when you ignore the costs of global warming.

That point in time, when alternatives are just straight up cheaper than coal, isn't too far away.

From a certain level of abstraction, if countries always did the economically rational thing, we wouldn't be in this mess at all. Building out solar capacity requires planning and foresightedness and political will. Hell, America could transition entirely to solar power for a fraction of the price of the Iraq war - in that sense, sustainable power is already cheaper than carbon-based, once you factor in the externalities of middle-eastern instability. If you factor in all the externalities - pollution, environmental destruction etc - then sustainable has been "cheaper" for a very long time.

The trouble is that countries are not purely rational, and do not factor in all externalities.

Or maybe Solar will never be the environmental fix-everything that people hype it as - https://www.youtube.com/watch?v=ciStnd9Y2ak

Why was it so important to you to say something so perversely selfish that you felt compelled to make a throwaway account to do so?

That's an attitude that we can all apsire to.

Probably still going to be your family's problem..

Not with that attitude :)

Indoor air co2 only lowers due to outdoor filtration. So, higher outdoor co2 will make us reach higher indoor levels faster. A change of outdoor air to 500 from 400 ppm, for example, means there's 16% less difference with indoor air at 1000 ppm.