Net Zero Carbon and Zero Carbon - What’s the difference?

 Net Zero Carbon and Zero Carbon

–        What’s the difference?

–        Does it matter?

–        Is there a better way?

Of course it matters, because these are wildly different things, with hugely different consequences.

Net Zero Carbon is the aim of many countries, who following COP26 are saying that their collective individual efforts will meet the aims of the Paris Agreement, to keep global overheating below +2°C and hopefully below +1.5°C.

There are a number of different problems about each country managing their own efforts with no overall binding global plan, and the option to drop out like Trump did. But the main problem is that even if everything goes as hoped, the world remains in a dangerously overheated state: temperatures never drop back down again. Net Zero means that CO₂ (Carbon Dioxide) emissions balance sequestration: additions balance subtractions. So CO₂ levels remain high, keeping temperatures high. It’s like climbing a poorly supported ladder that is only just in balance. The higher you climb, the more dangerous it is, and the more likely disaster is to happen. The safe thing to do is climb back down the ladder. But with Net Zero Carbon we stay balanced high on the ladder. Zero Carbon means we climb back down the ladder, to the very bottom and stay safe.

These three graphs from my Climate Model illustrate the global situation. Note the difference between the 2050 deadline that most have agreed, and the 2060 deadline which China has said they will follow.

Graph of Net Zero Carbon by 2050

Graph of Net Zero Carbon by 2060

Graph of Zero Carbon

As can be seen, the delay of just ten years pushes the temperature increase above +2°C. Also it takes a very long time to get to Zero Carbon, even reducing emissions by 5% of the previous year each time. In fact because this is an exponential progress we never get to zero, just closer. But Zero Carbon does bring the temperature back down again.

Don’t take these graphs as being set in stone, they are illustrative, like all models. In reality, achieving a uniform reduction in the real world, with each country doing its own thing, is nearly impossible under the COP26 agreement rules.

There is another problem with the Zero Carbon approach. Is it realistic to expect a complete switch away from fossil fuels? Is it even necessary? My final graph suggests that as far as bringing temperatures back down to a safe level goes, there is a safe middle way which still allows some use of fossil fuels.

Reducing to 25% of Carbon

This doesn't reduce temperatures as quickly as with Zero Carbon. Also temperatures still go above +2°C. But that can be changed by reducing carbon more quickly as follows.

Reducing to 25% of Carbon More Quickly

A better, more certain way, of ensuring carbon emission limits are achieved is required, but that I have already outlined in Pages on this Blog.