Forget Net-Zero, the Target Should Be Absolute Zero

A report from the United Kingdom shows how to to do it.

Wind turbines in the snow
Not quite Absolute Zero, but cold.

GeorgeClerk/Getty Images

Net-Zero is not a popular term on Treehugger. We have variously called it a dangerous distraction and a fantasy. Take our official definition:

What Is Net-Zero?

Net-zero is a scenario in which human-generated greenhouse gas emissions are reduced as much as possible, with those that remain being balanced out by the removal of greenhouse gas emissions from the atmosphere.

The problem is there are only two ways of removing greenhouse gas emissions from the atmosphere: technology (which has not been shown to work at scale) and trees (which are burning faster than we can plant them).

A British group of researchers from the Universities of Cambridge, Oxford, Nottingham, Bath, and Imperial College London, under the name UK Fires, has proposed a different approach and says forget the net, go for Absolute Zero. They explain what they mean by "Absolute Zero" in the context of current British plans for dealing with the climate crisis:

"The UK’s Climate Change Act contains two “escape” words: it discusses “net” emissions and targets on those that occur on our “territory.” However, in reality, apart from planting more trees, we don’t have any short-term options to remove emissions from the atmosphere, and even a massive expansion in forestry would have only a small effect compared to today’s emissions. Furthermore, shutting factories in the UK doesn’t make any change to global emissions, and may make them worse if we import goods from countries with less efficient processes."

These escape words are used everywhere. It's why we keep going on about consumption rather than production because the emissions numbers from rich countries don't count the carbon emissions that have been offshored to China, and don't include international aviation or shipping. Absolute zero means absolute and zero.

The target of zero emissions is absolute - there are no negative emissions options or meaningful “carbon offsets.” Absolute Zero means zero emissions;
The UK [or any nation] is responsible for all emissions caused by its purchasing, including imported goods, international flights, and shipping.

The report came out in 2019 but we learned of it from a recent tweet of the very startling graphic representation of the plan of action to reach Absolute Zero. Although it was produced for the U.K., this approach is universal.

UK Fires graph
UK FIres

Let's start right at the top with the road vehicles; it's no surprise that they are calling for all vehicles to be electric. However, their view of electric vehicles doesn't end with the power source: They note that currently, cars weigh 12 times as much as the passengers so that most of the energy is being used to move the vehicle, not the people in it. Given limitations on the electrical supply, this will be a serious problem with EVs.

"The transition to electric cars is already well underway, and with increasing demand, costs will presumably fall. We already have targets for phasing out non-electric vehicles, but by 2050 will have only 60% of the electricity required to power a fleet equivalent to that in use today. Therefore we will either use 40% fewer cars or they will be 60% the size." 

Now, as someone who gets attacked every time I mention that size and weight matters, even with EVs, it's gratifying to see this point made in relation to cars and the bigger picture:

gap between supply and demand
UK Fires

If you electrify everything–which we all agree that we have to–you need a lot more clean zero-carbon electricity than we have or are likely to have, so you have to reduce demand to eliminate the "anticipated energy gap."

Meanwhile, rail should be expanded and totally electrified, because aviation has to basically contract to almost nothing because "there are no options for zero-emissions flight in the time available for action." This will be good for the local economies, though: "Without flying, there will be growth in domestic and train-reach tourism and leisure."

Mining and materials, steel, and cement production all have to change. "All existing forms of blast furnace production, which are already under great pressure due to global over-capacity, are not compatible with zero-emissions." Cement production is incompatible, so there is an "urgent need to develop alternative processes."

In housing and construction, the same rules apply as for cars–electrify everything with heat pumps, but reduce demand to 60% of what it is now in total to eliminate the anticipated energy gap. That means reducing demand by retrofitting and insulating roofs and attics and building everything new to the Passivhaus standard.

"For new build homes, Passive designs which only use the sun for heating, and need electricity only for ventilation, lighting and appliances are now well established. Until 2015, the UK’s zero-carbon homes standards promoted this form of design, which is applied rigorously in Sweden, and at current rates of building, would affect 20% of the UK’s housing if enforced now. The cost of houses built to the Passive standard is approximately 8-10% more than standard construction, and the thick walls required slightly reduce the available internal space, in return for zero energy bills."

They also call for a change in codes to measure upfront carbon or embodied energy, and also to regulate sufficiency, or not building more than is actually needed, with more material that is needed.

"The building codes currently only specify the minimum amount of material to be used (including the margin of safety). But they could also enforce an upper limit, adding an “and no more” clause. There is also no existing benchmark to compare the embodied energy of the materials in a building per square metre of but this would help drive the efficiency of structural design."
reducing energy use
UK Fires

The same rules apply to housing as to any other manufactured product from clothing to packaging—reduce demand to 60% of today's levels, which doesn't sound unreasonable or impossible, by making things last longer, reducing the size and eliminating overdesign, increasing energy efficiency. Get it down to 60% and there is probably enough clean and renewable low-carbon electricity to run it all.

It is all a mix of Treehugger themes where we have called for sufficiency as well as efficiency, and our more recent mantras:

  • Reduce Demand
  • Clean up Electricity
  • Electrify Everything

Individual Actions Matter

The report notes that substantial changes in the way we live are required but we can still live well. We need to stop flying but can start taking trains. We need to buy less stuff in total and more that is made locally. We need to eat less beef and lamb, and more local food. And as we keep saying, our purchasing decisions matter: "Each positive action we take has a double effect: it reduces emissions directly and it encourages governments and businesses to be bolder in response."

In an earlier discussion about individual actions, I noted that they can turn into mass movements pretty quickly and change the attitudes of a big part of the population. I wrote: "People who smoke are now pariahs, and look at what is happening with the #metoo movement. Attitudes are changing. Individual actions lead to collective consciousness." The Absolute Zero report says much the same thing, that individual and collective behavior can change, and in fact, has to change.

"Not long ago, smoking cigarettes was encouraged and considered to be acceptable in public spaces that children frequented, drink-driving was practiced with such regularity that it killed 1000 people per year in the UK, and discrimination based on sexual orientation was written into law. These behaviours now seem reprehensible, showing society is capable of acknowledging the negative consequences of certain behaviours and socially outlawing their practice. Focus should therefore be centred on expediting the evolution of new social norms with confidence that change can happen."

And people can be very happy living in a low carbon environment. They may not have fast cars and boats, but many have found you don't need that to be happy. Perhaps we have been delivering our message poorly and selling the wrong product.

"Language used to promote zero-emissions should no longer focus on an ‘eco- friendly’ and ‘green’ lexicon, but rather candid descriptions of actions that appeal to human fulfillment. Evidence from time-use studies shows that human fulfillment does not strictly depend on using energy – the activities we enjoy the most are the ones with the lowest energy requirements. Consumers can be satisfied in a zero-emissions landscape."

We can do this

The report starts with the daunting chart, but in the end, it is a very positive and reasonable document that mixes the ideas of the electrify everything crowd, with the insight that we do not have to reduce energy consumption to zero (an impossible task anyway) but that if we are going to have enough zero-carbon electricity to run everything then we do have to reduce demand, to about 60% of what it is today.

Those things that we can't electrify, like flying, are just going to have to go away until we can. Those materials that we can't make zero-carbon, like new steel or concrete, we are just going to have to figure out how to do without. But it is all doable with current technology: There is no reliance on hydrogen or machines that suck carbon out of the air; there is just a mix of sufficiency, efficiency, and decarbonization. It all sounds totally plausible.

Download the report here.

View Article Sources
  1. Allwood, J., et al. . "Absolute Zero." UK FIRES, 2019,  doi:10.17863/CAM.46075