all the atmospheric increase is us.
Let's assume for the sake of argument that was a proven fact. It isn't, but we'll just assume for now that it is.
Emitting zero carbon is beyond our ability as a species - things we eat rot and the air we expel during breathing contains elevated CO2. So what we're left with is trying to minimise our collective output.
Minimising our output can be achieved in just two ways - lower output per person,or fewer people.
Efficiency gains should reduce our output per person, but they haven't, because we've found other uses for that energy - flight, air con, a lot of computers etc. People who were poor and had limited access to heating/cooling, transport, or power are now more wealthy and have raised their output per person.
People simply won't go back to an agrarian lifestyle, they just won't, so we can only reduce emissions per person by changing how the power they consume is generated. As vehicle propulsion currently means hydrocarbons, we can only target coal/gas/oil fired power stations for replacement with nuclear.
The above, if it could be implemented globally without proliferation of nuclear weapons, would reset our emissions by a generation or two. The issue then becomes flight. People are flying more often and further than ever before. Families don't live in the same town anymore - they don't even live in the same country or even continent. Only one couple I know are from the same country: the rest must fly to visit family. Jet engines are being made more efficient, but the increase in number of flights will dwarf engineering gains. Automotive uses will be a sideshow to air travel. Trains are still powered by coal (its just burned in the power station rather than the steam engine), which is the worst fuel in terms of CO2:Energy output.
Absent a carbon neutral jet fuel and some realistic way to power electric cars from nuclear fuel, all we have done is extend the timeline until we inevitably come face to face with route #2 - fewer people.
You can't double the population and expect emissions to fall. It isn't realistic. So how do you get the population to shrink? Well, you need to reduce the number of children being born. The debate on how best to achieve that can be expected to be heated & emotive, but ultimately you'd have to look to complusory sterilisation after the second child. A capitalist alternative would be to auction permits to have children. That's not something you could force on people without being absolutely certain the science is right this time and that the conclusions drawn from that science are also correct. We're simply nowhere near that point. Things like the CRU hack and all the crying wolf just discredit the 'science' more each year.
Logically, to minimise economic damage - for society will still need an economy - the least harmful way to reduce the population is to reduce childbirth within the lower half of the economically active adults. The poor, in other words. We'd need to maximise economic activity per person with fewer people in order to minimise the reduction in econoic activity you see, meaning only the well off could breed.
So what are your answers? What is your road map? There'll be plenty of downvotes for this, but predictably no answers. Slapping a few pence per litre on petrol, a couple of quid on the air passenger levy, and a few hundred on domestic power bills just doesn't change anything. So be honest about how you'd solve the issues... are we rationing child birth or auctioning permits to do it, or are we banning transport entirely and letting grandma freeze to death this winter? Are we having a really big war to whittle down the numbers, or making Logans Run real?
Let's just say that you don't have any answers, because you don't. You'd never be able to convince the world to follow your plan. Even assuming all climate 'science' is accurate as presented, all we have left in the toy box then is learning to live with the effects of any climate change. To accept it will happen at an ever escalating rate, and to try to reduce its impact upon us. Anything else is just wasting time and resources, assuming you're right about AGW of course. I don't sweat it, because I know you're not, or people like the CRU wouldn't be spinning their research while hiding or destroying their data to prevent it being analysed by more rational minds.