I get the basic maths. If you have something, and you offset it with negative something, you have nothing. If all those damaging climate emissions can be cancelled-out with ‘negative climate emissions’ the party can continue. But this is a fantasy. There is no way societies can offset carbon emissions in the time left, even with John Kerry’s magic beans.

First, let’s look at the target. To avoid catastrophic and unstoppable climate change, societies need to keep the concentration of CO2 in the atmosphere below 450 parts per million (ppm). If humanity breaches that level it sets off a series of chain reactions which will make most of the planet uninhabitable, with large parts it unlivable by 2050.

In May 2021, the concentration hit 420ppm. That’s nearly 4ppm higher than the year before. So, it’s really quite simple. If societies keep generating emissions at the current rate, it’s game over in 2029.

That’s a bit of a worry, when there are no serious plans for countries to cut emissions until 2030.

It also means that setting a carbon neutral date – a net zero target – of 2050 (or 2060 in China) is a complete waste of time. It’s too late.

Yet that is what the world is doing.

I strongly suspect those advocating net-zero know all this. What they are doing is greenwashing, telling people who don’t understand how serious the situation is that there are tough emissions targets, and though these are far off in the future, and those making them will have long retired, there is the appearance of action and so no need for any change now.

Planting trees is a popular way to meet these targets. The most ambitious reforestation plans suggest that trees could remove 200 giga tonnes of carbon from the atmosphere in 50 to 100 years. To put that in context, annual equivalent carbon emissions (that is, accounting for the other main greenhouse gases as well as CO2) are just over 40 giga tonnes. So all those trees could absorb five times today’s carbon emissions, which is really good, but because they will take so long to grow, their impact will come 75 years too late. Trees also have an irritating habit of dying, or burning when they get too hot, and releasing all the carbon they’ve stored back into the atmosphere.

Trees store carbon for a while, and then release it. That’s what I call net zero.

Dream big not small

All those seemingly dramatic claims by big corporates are drops in the ocean too. Shell wants to offset 120m tonnes of emissions by 2030(!). Nestle wants to cancel 13m tonnes and (wow) make Kitkats carbon neutral by 2025. BA says 10% of its flights will be carbon-neutral by 2030, while the shipping industry brazenly admits it will actually increase emissions in the next ten years.

Combined, these (not even vaguely) ambitious goals will have almost zero effect on global emissions.

The 40+ giga tonnes of emissions generated today come from a bewildering array of man-made sources, from buildings and vehicles, to cement production and deforestation. To slow the pace of climate change societies need to cut these emissions to ACTUAL zero as fast as possible – regardless of the cost.

Then they have to invest in new technologies (John Kerry’s magic beans) to try and offset the additional ONE giga tonne of emissions that are now being released each year AS A RESULT of human activities – from the wildfires around the world, from under the warming oceans and from melting permafrost, for example.

To do this, societies will have to build HUNDREDS of carbon capture plants and run them at full blast for more than century to bring the atmosphere into better equilibrium. And, even then, even having done all that, they will have maybe a 50:50 chance of avoiding the worst.

The main problem now, you see, is not the volume of greenhouse gas emissions. They are only adding to the biggest problem. The main challenge is to reduce the concentration of greenhouse gases in the atmosphere, which is the result of burning fossil fuel for the last 200 years. All net zero says is that societies plan to stop making that problem worse, and that they plan to stop doing that in another 20 or 30 years. But the average temperature of the planet will not start declining until the concentration of gases begins to fall, and that can only happen in two ways. Either it can happen naturally, and the excesses gases will get absorbed by the plants and oceans. That will take centuries. Or, societies can invest in carbon capture, though that too is fraught with problems.

Forget net zero, climate people. Just as you can’t offset a 20-a-day smoking habit with 20 minutes on a treadmill, you can’t cancel 40+ Gt of CO2 emissions each year by planting a few saplings next week.

Societies need to embrace radical change if they are to avoid a climate catastrophe, or there is no point in making any change at all.