Musings on Net Zero

Well we're here again. A number of the usual suspects either claiming that global warming and climate change is a hoax or at least exaggerated, and/or claiming that it's too expensive to do anything about it. I guess despairing completely that we're even having this debate yet again is one option. But I thought I'd share the arguments that convinced me of the reality of it all, and why it's essential we continue doing what we can to get to Net Zero on (or ideally well before) 2050.

I remember it being in the late 90s when I first really started to notice significant discussions around Global Warming. I wasn't a climate change sceptic, but hadn't really engaged with the arguments on either side at that point.

The thing that grabbed my attention was driving back from a client meeting and listening to BBC Radio 5 Live. They had an interview with Professor Chris Rapley, Head of the British Antarctic Survey, and no 'mung-bean munching, tree-hugging eco freak' (TM Boris Johnson). There had been discussions at the time that the science around global warming was complicated, and not decided upon. He explained it all so clearly it has stayed with me since. His argument went like this:

Is Global Warming Real?

And the answer? Yes average global temperatures have been rising steadily throughout the last century and continue to do so. If they weren't there wouldn't be anything to worry about? The graph below illustrates this.

Source Global average temperature datasets?from?NASA,?NOAA,?Berkeley Earth, and meteorological offices of?the U.K.?and?Japan,

Is it Caused by Greenhouse Gasses?

He went on to explain that the greenhouse effect is a long established phenomenon whereby light from the sun reaches the earth, where it is converted to heat and reflected back. The greenhouse gasses, mainly carbon dioxide but also methane, ensure that not all the heat escapes. This has generally had a (very) benign effect as without it the earth's surface temperature would be -18 degrees Celcius, and not suitable for life, and so none of us would be reading this in the first place. The problem occurs when the concentration of the greenhouse gasses gets too high, and we hit a situation where runaway warming starts to occur. Which we're close to getting to.

But is it Man Made?

The sceptic argument here normally points out that there have always been temperature fluctuations, and also fluctuations in the concentration of the greenhouse gasses, so why the panice now? Well this is where the Antarctic Survey bit comes in.

The professor talked about how his team can drill down and take out a cyclinder of ice from the ice shelf. They know that the bottom of this was formed about a million years ago. And in the ice are lots of air bubbles. They pop the bubbles and can analyse the make-up of the atmosphere at that time.

What they found is that for pretty much the whole of the past million years the CO2 concentration has varied between 170 and 270 parts per million. In the last hundred years it has stated to increase to levels never before seen. The graph below shows this over 800,000 years:

Source: https://www.climate.gov/media/13685

Which is pretty clear evidence that what we're seeing is the result of the additional greenhouse gasses being pumped into the air as a result of industrialisation.

Putting it all Together

So if we put it all together:

1. The earth is getting warmer
2. The greenhouse effect does have a significant warming effect
3. The greenhouse gas concentrations have been massively increasing since the industrial revolution
4. If we don't act now it's going to hit a tipping point and spiral out of control

Well it convinced me anyway.

OK, but can we afford It?

Well there is an argument that goes 'can we afford not to?' But questioning what effect getting to Net Zero will have on the economy is clearly one that is worth exploring, and that is going to be explored.

Here views have shifted considerably over the past few years, and continue to shift in the right direction. When the climate change act was passed in 2008 the estimates at that time were that an 80% reduction in emmisions would result in a 2% hit to GDP. More recent estimates show it to be significantly below this, and reducing all the time as technology advances. Add to this the additional significant benefits including a cleaner greener environment, increased energy security and ultimately lower bills.

I'd hoped this 'debate' was behind us, but that appears to have been me being over optimistic, which isn't something I'm often accused of. But all the evidence shows that we need to continue and probably accelerate our commitment to Net Zero, whatever the sceptics say.