That might be a sensible objective. It does remain to be seen if this is actually possible at all. Same problem: The concept of net zero carbon is admirable, yet the reality of achieving something like that is closer to a fantasy than reality.
In other words, we might be able to slow the rate of CO2 contribution. It is likely impossible to get it down to zero. Maybe in a few hundred years? That's as easy to predict as someone in 1824 predicting that we would have computers on every desk and our pockets, MRI machines, etc.
Note that achieving net zero does not slow down or reduce atmospheric CO2 accumulation. It will continue to rise.
And, of course, to reverse course, not only do we have to achieve net zero (which is impossible), we would have to go net negative in a very substantial way.
And that's where the "WTF are you talking about?" part comes in when listening to the fantasies being sold. Going net zero would require planetary scale resources and energy we cannot even imagine. Going negative is orders of magnitude worse.
When you move and use resources of any kind at a planetary scale, you will use unimaginable amounts of energy. Physics tells us that no process can ever be 100% efficient. In fact, most complex processes are quite inefficient when evaluated from start to finish. Assuming, say, 50% efficiency, that means that we would have to generate twice the planetary scale energy required to achieve this (if it were possible). The same is true of resources such as minerals, manufacturing, processing, transportation, digging, whatever. Which, in turn, means that we would then introduce a seriously massive amount of pollution and cause collateral effects/damage to the environment, again, at a planetary scale.
That's where the conversations go loopy very quickly. Its easy to say "cover the Equator with solar panels". It isn't easy to explain how we would do that without destroying entire ecosystems around the planet and introducing so much additional pollution that things would get worse rather than better.
The planet will address this problem naturally. We can clean-up our act to help. Yet, we should not go to insane lengths in doing so. The risk is to cause more damage and to do so at a very serious scale. In other words, in an effort to save life on earth we could, instead, succeed at killing everything on this planet.
A nice thing that physics tells us is how to precisely imagine even amounts of energy that vastly exceed the observable universe. In https://news.ycombinator.com/item?id=42423291 I have calculated roughly how much energy is needed and how much it will cost, in https://news.ycombinator.com/item?id=42424292 I have explained why this doesn't violate either the laws of physics or even the demonstrated of currently deployed systems, and in https://news.ycombinator.com/item?id=42424748 I have outlined how we would do that without destroying entire ecosystems around the planet or introducing additional pollution.
Predicting what will happen is much more difficult than calculating what can happen, but we seem to be on a good path, with atmospheric carbon capture becoming feasible at the necessary terraforming scale within decades rather than centuries.
In other words, we might be able to slow the rate of CO2 contribution. It is likely impossible to get it down to zero. Maybe in a few hundred years? That's as easy to predict as someone in 1824 predicting that we would have computers on every desk and our pockets, MRI machines, etc.
Note that achieving net zero does not slow down or reduce atmospheric CO2 accumulation. It will continue to rise.
And, of course, to reverse course, not only do we have to achieve net zero (which is impossible), we would have to go net negative in a very substantial way.
And that's where the "WTF are you talking about?" part comes in when listening to the fantasies being sold. Going net zero would require planetary scale resources and energy we cannot even imagine. Going negative is orders of magnitude worse.
When you move and use resources of any kind at a planetary scale, you will use unimaginable amounts of energy. Physics tells us that no process can ever be 100% efficient. In fact, most complex processes are quite inefficient when evaluated from start to finish. Assuming, say, 50% efficiency, that means that we would have to generate twice the planetary scale energy required to achieve this (if it were possible). The same is true of resources such as minerals, manufacturing, processing, transportation, digging, whatever. Which, in turn, means that we would then introduce a seriously massive amount of pollution and cause collateral effects/damage to the environment, again, at a planetary scale.
That's where the conversations go loopy very quickly. Its easy to say "cover the Equator with solar panels". It isn't easy to explain how we would do that without destroying entire ecosystems around the planet and introducing so much additional pollution that things would get worse rather than better.
The planet will address this problem naturally. We can clean-up our act to help. Yet, we should not go to insane lengths in doing so. The risk is to cause more damage and to do so at a very serious scale. In other words, in an effort to save life on earth we could, instead, succeed at killing everything on this planet.