Net zero began as a description of the planet’s carbon budget. It now describes jobs, buildings, and growth, and means less with every year.
Net zero. It’s a phrase that has become popular to the point of being overused and, perhaps, losing any real meaning. It can stand alone, or, more commonly, precede something else, from net zero growth to net zero jobs, from net zero vehicles to net zero homes. It’s a phrase that environmentalists love, climate sceptics less so. Regardless of our political stance, we all like to think that we know what it means, but do we, really?
In fact, the phrase itself is far newer than it actually sometimes feels given the frequency and abandon with which it is used. There was certainly no mention of ‘net zero’ at the Rio Earth Summit back in 1992. Instead, most climate scientists spent the 1990s and a lot of the 2000s talking about stabilising concentrations of carbon dioxide in the atmosphere, which sounds similar but really isn’t (you can hold concentrations steady while the planet keeps warming for decades, since the oceans take their time). It was from Oxford, and in particular from Myles Allen, whose work on the trillionth tonne showed that warming tracks the cumulative total of carbon dioxide ever emitted, and therefore stops only when net emissions do, that the idea of thinking more about emissions came. The Intergovernmental Panel on Climate Change (IPCC) then picked the idea up in its fifth assessment report (in 2014), and a year later it went into Article 4 of the now landmark Paris Agreement, which wants countries to “achieve a balance” between anthropogenic emissions by sources and removals by sinks in the second half of this century. Sweden in 2017 was the first country to set a date in law (in this case 2045).
In practice, what net zero means is that whatever carbon dioxide humans pump into the atmosphere must be taken out again by something we are actively doing, and the net is there because nobody (least of all aviation, or cement) can get to actual zero in the current timescale, no matter what anyone claims. What it does not mean (and Allen has spent much of the past few years no doubt frustratedly pointing this out), is holding the atmosphere steady by any magical balancing act. Fossil carbon comes out of the ground and, to count, has to go back into the ground or somewhere equally permanent. Not wanting to be the bearer of bad news, but planting trees to offset a flight are not the same thing (Not that planting trees is inherently a bad thing).
Net zero is in fact a lot simpler than its proponents (or critics, for that matter) claim. It was designed to be a description of the planet, the whole of it. It was really designed to describe a job, or a pension fund, or an economic policy, and certainly not a block of flats. Alas, once it escaped physics and became a political or corporate target it became something else entirely, a promise about 2045, or 2050 (or later) made by people who will most likely have retired by 2035 and perhaps even passed away by 2050. Three scientists, James Dyke, Robert Watson and Wolfgang Knorr, warned in April 2021 that the concept was in fact a “dangerous trap” that had presented humanity with a “burn now, pay later” golden ticket.
Is it, then, achievable? For the planet, in the second half of the century, the science says that it needs to be, because otherwise the warming will not stop (which as the recently passed summer demonstrates spells disaster across the globe). For individual countries, net zero depends almost entirely on what they have got to work with. At least eight countries claim that they are already there: Bhutan, Suriname, Panama, Gabon, Guyana, Madagascar, the Comoros, and Niue. None, it might be added somewhat cynically and with all due apologies, are major economic powers. Instead, what they do have in common are lots of trees and not that many people, which is not really a policy that too many other countries are in a position to copy. It should also be pointed out that Guyana managed to achieve net zero while becoming one of the world’s newest oil producers (Guyana produced its first oil in December 2019), which suggests that the word ‘net’ is doing a fair bit of heavy lifting. The Net Zero Tracker counted 137 of 198 national governments with a net zero target (however unambitious) in September 2025, covering 77 per cent of global GDP once the American federal government had walked away (it had been 93 per cent). Of the companies (and not countries) it assessed, only seven per cent met its basic integrity criteria.
Net zero everything
Which brings us back to all those net zero somethings. A net zero building, in the EU at least, now has a legal definition. From 2028 for public buildings (and 2030 for everything else) any new construction must be a zero-emission building with very low energy demand, no gas boiler, and power from renewables on site (or at least nearby). What the definition does not include are the bricks and mortar (not to mention the steel) the building is in all likelihood made from (wooden skyscrapers are not yet a big thing). In other words, a zero-emission building is a building that emits nothing only once you have completed its construction.
When it comes to ‘net zero jobs’ the definition is even looser. The Energy and Climate Intelligence Unit, with CBI Economics, reported in June that in the UK the net zero economy supports 1.1 million of these jobs, paying an average of 43,142 UK pounds per year against the national average wage of of 39,039 UK pounds. Solar panel and battery installers (and the people who make things), heat pump fitters, people working on electric car production lines are all, in theory, doing ‘net zero jobs’ but only, it might be argued, because their respective firms operate in a sector the report’s authors have chosen to call net zero, not because anyone has measured whether it actually removes any carbon from anywhere (the same report notes, in passing, that the methodology changed this year, so the 1.1 million cannot be compared with last year’s figure). Net zero growth is a different thing entirely, and equally fuzzy in how it’s measured.
None of this is meant to put down the idea of net zero or suggest it’s wrong. But it does mean that the phrase is being asked to do a great deal of work by people who might not fully understand it. Others still want the whole concept done away with completely, again without really exactly knowing what they’re talking about. Before you use the words ‘net zero’ again yourself, make sure you know precisely what they mean.
Photo: Dreamstime.