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Net zero by 2050 will hit a major timing problem technology can’t solve.

We need to talk about cutting consumption – Mark Diesendorf

“PaFaWag 102E #EP08-007” by D29-1 is licenced under CC BY-NC-ND 2.0

Many climate activists, scientists, eng-ineers and politicians have been trying to reassure us the climate crisis can be solved rapidly without any changes to lifestyle, society or the economy.

To make the vast scale of change palatable, advocates suggest all we have to do is replace fossil fuels with renew- able power, construct electric vehicles and other energy efficiency technologies, add seaweed to livestock feed to cut methane, and embrace green hydrogen for heavy industries such as steel-making.

There’s just one problem – time. We’re on a very tight timeline to halve emissions within eight years and hit net zero by 2050. While renewables happen to be making major inroads, the world’s overall primary energy use continues to rise. That means renewables are chasing a retreating target.

My new research shows that if global energy consumption grows at the pre- COVID rate, then major technological change alone will not be sufficient to halve global COemissions by 2030.

We will need to cut energy consumption 50-75% by 2050 while accelerating the renewable build. And that clearly implies implementing lifestyle change driven by social policies.

The limitations of technological change

We must confront a hard fact: In the year 2000, fossil fuels supplied 80% of the world’s total primary energy consumption. In 2019, they provided 81%.

How is that possible, you ask, given the soaring growth rate of renewable electricity over that time period? The answer is that world energy consumption has been growing rapidly, apart

from a temporary pause in 2020. So far, most of the growth has been supp- lied by fossil fuels, especially for transportation and non-electrical heating.

The 135% growth in renewable electricity over that time frame seems huge, but it started from a small base. That’s why it couldn’t catch fossil fuelled electricity’s smaller percentage increase from a large base.

As a renewable energy researcher, I have no doubt technological change is at the point where we can now afford- ably deploy it to get to net zero. But the transition is not going to be fast enough on its own. If we don’t hit our climate goals, it’s likely our planet will cross a climate tipping point and begin an irreversible descent into more heat- waves, droughts, floods and sea-level rise.

Our to-do list for a liveable climate is simple: convert essentially all transportation and heating to all-electric operation while switching all electricity production to renewables. But to complete this within three decades is not simple.

Even at much higher rates of renew- able growth, humanity will not be able to replace all fossil fuels by 2050. This is not the fault of renewable energy.

Other low-carbon energy sources like nuclear would take much longer to build, and leave us even further behind.

Do we have other tools that can be used to buy time? COcapture is get- ting a great deal of attention, but this technology seems unlikely to make a significant contribution. The scenarios explored in my research assume that removing COfrom the atmosphere by carbon capture and storage or direct air capture does not occur on a large scale, because these technologies are speculative, risky and also very expensive.

The only scenarios in which we succeed in replacing fossil fuels in time require something quite different. We can keep global warming under 2if we slash global energy consumption by 50% to 75% by 2050 and greatly accelerate the transition to 100% renewables.

Individual behaviour change is useful, but insufficient

Let’s be clear: individual behaviour change has some potential for mitigation, but it’s limited. The International Energy Agency recognises net zero by 2050 will require behavioural changes as well as technological changes. But the examples it provides are modest, such as washing clothes in cold water, drying them on clotheslines, and reducing speed limits on roads.

The IPCC report on climate change mitigation (for 2022) has taken a step further, acknowledging the importance of collectively reducing consumption of energy with a chapter on “Demand, services and social aspects of mitigation”. To do this effectively, government policies are needed.

Wealthy people and wealthy countries are overwhelmingly responsible for greenhouse gas emissions. It follows that we need to reduce consumption in high-income countries while improving human well-being.

We’ll need policies leading to large scale consumption changes

We know the technologies available in our toolbox to tackle climate change are: renewables, electrification and green hydrogen. But while these will help drive a rapid transition to clean energy, they are not designed to cut consumption.


These policies would actually cut consumption, while also smoothing the social transition:

1. a carbon tax and additional environmental taxes
2. wealth and inheritance taxes
3. a shorter working week to share the work around
4. a job guarantee at the basic wage for all adults who want to work but can’t find a job in the formal economy
5. non-coercive policies to end population growth, especially in high income countries
6. boosting government spending on poverty reduction, green infrastructure and public services as part of a shift to Universal Basic Services.

You might look at this list and think it’s impossible. But just remember the fed- eral government funded the economic response to the pandemic by creating money. We could fund these policies the same way. As long as spending is within the productive capacity of the nation, there is no risk of driving an undue level of inflation.

Yes, it is true that these policies mean major change. But major disruptive change in the form of climate change is happening regardless. Let’s try to shape our civilisation to be resilient in the face of change.

Source: The Conversation, 28 April 2022

Reproduced under a creative commons arrangement.

Dr Mark Diesendorf is Honorary Associate Professor at the UNSW Sydney, and is an ERA member.

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