Glasgow 2021 and the fallacy of Net Zero (or a beginner’s guide to climate change)

Updated: Mar 9

Dr Mark Nicholson

Every Sunday morning for many years now, I walk through the tea-fields next to my home in Kenya to have breakfast with my 85-year-old neighbours (when I or they are not “up-country” or out of the country). They were born three days apart, shared the same crèche and have been married for well over 60 years. Mister is a modest but highly successful tea planter achieving tea yields that the large international tea producers would be profoundly envious of.

If it has rained, the first question he or any Kenya farmer will ask is “How much rain did you have last night?” (We know because we all measure.) The ex-colonials will reply with something like “Oh, 95 points”, which translates to 95/100 of an inch, or in modern parlance 24mm. The secret is to try and impress (or depress) them by responding “Oh, bad luck, we had 33mm”. Yes, rain is usually our friend.

But not now. It is February and at this time of year we expect blue skies and brown, parched lawns. But for several years the skies have been cloudy for much of the year, the temperatures at 2300m (7600ft) lower than in the past, and February is no longer dry (last Saturday night we had 79mm). We can blame El Niño, La Niña or simply a changing climate. One theory is that as the Indian Ocean heats up, the evaporated water (moisture) blows over the equatorial African highlands and dumps increasing amounts of rain on us. For a tea farmer at this time of year such rain spells gloom: more rain at the wrong time of year means more tea to pluck, a higher wage bill, oversupply on the world market and falling prices. But don’t think the overall effect is cooling. I spent the weekend on Mt. Kenya. Fifty years ago glaciers gleamed in the sun. Today there is only a pathetic covering of ice which will be gone within a year or two.

So, what is the explanation? The answer is, indeed, climate change. With us it seems to mean a cooling climate as the cloud cover increases, sunlight decreases and temperatures fall. For most of the rest of the planet, it means the opposite. 99 percent of scientists now concur with the view that the driver of climate change is increasing CO2 in the atmosphere, and that the source are burning fossil fuels and other activities such as cement manufacturing where limestone (CaCO3) is ‘slaked’ and CO2 is given off.

For the less scientifically inclined, let me give a brief overview. Most (78%) of the air we breathe is nitrogen and the rest is oxygen (19%). A tiny fraction (0.00028%) is, or was, CO2, one of the main ‘greenhouse gases’. That is such a small figure that we use parts per million (ppm). From the examination of ice cores, we know that this level has been the same (280 ppm) for the last 10,000 years and at that level or quite a bit lower for the last 800,000 years. Since the Industrial Revolution, the level has been rising and it is now over 400 ppm and increasing steeply, more or less in line with the human population. That figure is more than alarming, it is terrifying. But even more terrifying is that the majority of people are still blissfully unaware of the danger. CO2 is a heavy gas, so it traps heat, and the result is global warming or what British chemist and earth scientist James Lovelock calls global heating. Lovelock is the creator of the Gaia hypothesis which suggests that the biosphere and all the physical components of the Earth (atmosphere, cryosphere, hydrosphere and lithosphere) are closely integrated to form a complex interacting system that maintains climatic and biogeochemical stability on Earth. But mankind is breaking down this stability.

Later this year in Glasgow, insh’Allah, the world will watch and listen to the grandly titled Conference of the Parties (COP26) of the United Nations Framework Convention on Climate Change (UNFCCC), an international environmental treaty addressing climate change, originally negotiated and signed by 154 states in Rio in 1992. It is known informally as the Earth Summit. These Conference of the Parties develop into a bun-fight with countries all trying to minimize the impact on their economies.

The problem with all these UN Protocols, Declarations and Accords is that after endless hand-wringing, the COPs promise everything and deliver almost nothing. Do you remember the result of COP3 in 1997: the Kyoto Protocol? It was doomed from birth because it excluded the world's fastest growing economies (notably China, also one of the largest) and developing countries (e.g. India) from binding targets. Moreover, the USA refused to ratify it. Twenty-three years later, and despite the Covid blip, the world economy is still growing. Look at any graph of CO2 levels and extrapolate to 2050 and you will arrive at 500 ppm or possibly much more, as the natural carbon sinks (mainly the oceans) fail to absorb more CO2.

That is only part of the problem. As the Earth warms up, two much more dangerous things will happen. The first is that the permafrost – currently almost 25% of the northern hemisphere - will start to melt, liberating vast amounts of methane (CH4). Methane is 84 times more effective at trapping heat than CO2. Secondly, as polar ice disappears, the amount of solar energy reflected into space (the albedo) goes down. Ice-albedo feedback is a vital aspect of global climate change: in polar regions, a decrease of snow and ice area results in a decrease of surface albedo, and the intensified solar heating further decreases the snow and ice area. So global heating will accelerate and the existing predictions for global warming may be hugely underestimated. If you are a Texan, don’t be deceived by the cold snap you have just endured: our world is getting hotter every year.

‘Net zero’ will become a buzz phrase this year. It means achieving a balance between the greenhouse gases emitted and those removed naturally from the atmosphere, so that we become carbon neutral. COP26 will attempt to persuade governments to be net zero by 2050. The reality is that we have little hope of achieving this because so many small economies are on the verge of a growth surge. But let’s say that we do achieve net zero by 2050. All that means is that we will allow CO2 levels to be no lower than the catastrophically high levels of 500-1000 ppm. Let me introduce an analogy here: the human body, like most homeotherms, maintains a very narrow range of core temperature of 2 or 3 degrees Celsius. The last time I had malaria my temperature hit 42 C and I felt as if I was about to cook to death. At that level all physiological systems begin to break down. It will be the same when CO2 levels go past 1000 ppm. Temperatures could rise more than 8 C, leaving many places uninhabitable, coastal cities inundated, and mass extinctions inevitable.

Our atmosphere is thin and precious: only 12 km thick. Yet we pump 35,000,000,000 to 45,000,000,000 tonnes of CO2 and other greenhouse gases into it every year. So what is needed is not net zero but finding ways of reducing atmospheric CO2 back to levels that ensure climatic stability. The technology is not there yet, but it may come. This is likely to be geochemical engineering on a huge scale that captures CO2 and turns it back in to carbonates such as chalk or limestone which can be buried underground.

I have learnt over the years that humans ignore slow-onset catastrophes. Droughts and famines take time to develop yet kill as many or more than earthquakes, tsunamis or even genocides on the scale achieved in Rwanda. But we ignore climate change at our peril. A few years ago, I ended my Christmas letter to family and friends by saying “Climate change is affecting our lives but we ain’t seen nothing yet”. My view has yet to change.