What Net Zero Takes
This Thursday was Earth Day. Happy 4.54 ± 0.05 billion-year anniversary Earth!
To mark the occasion, I appeared on a Straight Talk Live panel where I joined an inspiring group of young people who are taking action on climate change. The panelists were as young as 15, yet already writing books and founding organisations to take climate action.
Just by writing the lines makes me very optimistic about the progress in the world. We now have the tools to launch a company in a weekend. A book in a day. A newsletter in a few hours. We have the tools for boundless creation.
And Gen Z knows this. Greta Thunberg was 15 when she started the school strikes for climate change. Gen Z is starting strong. Prepare for a beautiful and bountiful world to come. This is the world they know.
And we’ll need that strength and innovative spirit, as we have a large challenge ahead of us.
The Earth has already warmed by 1ºC above pre-industrial time. That warming is caused by an increased concentration of carbon dioxide and other greenhouse gases. Current climate pledges mean that by the end of the century we will see a likely warming between 2.1ºC and 3.3ºC with 90% chance of exceeding 2ºC.
At this level of warming, the risks to people, economies and ecosystems are high. This includes large risks of irreversible changes in our world. We are heading from a period where weather and climate were relatively stable and predictable to an increasingly chaotic one.
To reduce the risks, we need to increase our global ambition and decarbonise as fast as possible.
The question posed to the panel was: is it too late for Net Zero? In my answer, I flipped the question and asked: what does it take for it not to be too late for net zero?
The answer is a lot.
We need to build at a scale we haven’t seen before. We need to grow the net zero economy at a rate of 10-20% every year and sustain this for decades.
The good news is that we have the tools to do so.
Let’s look at energy in the context of the United Kingdom.
Energy powers the world. Everything we do, from reading this newsletter to cooking food needs energy. The average person in the UK consumes about 30,000 kWh of energy every year.
The amount of sun energy that falls on the UK is about 750–1100 kWh per square metre per year. Assuming we can convert 10% of this into energy using a solar panel, we get bout 100 kWh per square metre per year of useful energy from a solar panel.
So, to satisfy the energy needs of a person in a year, we need about 300 square metres of solar panels per person to cover the current energy use.
The calculation gets a bit trickier when you consider efficiency gains. Part of our energy consumption is directly electricity - say to power a refrigerator. But some of it comes from burning fuel, such as in a car. An electric vehicle is more efficient at converting electric energy into motion, so the total energy consumption will decrease as we move to electric vehicles.
Thus, we’ll treat this number as an order of magnitude and say we will need about 100 square meters of solar panels per person. How much is this? It’s 2610 square miles, or about a third of the area of Wales.
This is comparable to a more complex estimate by Chris Goodall in What we Need to do Now, where he suggested we will need about 2% of the area of UK covered in solar panels by 2050. That’s a quarter of the size of Wales, or twice the size of Lake District National Park.
It’s a lot of land, but it’s do-able. How fast do we need to move? To cover this area, we need to expand the solar capacity by 20x by 2050. That’s doubling every 7 years, or a growth rate of 10% every year.
Can we do this? Installing solar panels is no longer an innovation problem. We have the technology, we just need to scale it at a planetary scale. It’s a logistics, planning and engineering problem.
How much will it cost? Let’s take a cost of £100 per square meter of solar panels. This gives us a total cost of £676 billion. Over 30 years, this amounts of 1% of UK’s GDP per year going into solar panels.
A large number, but very do-able.
This is just an example of the calculations we will need to make. These are the type of calculations that I make every day as a decision maker to separate my feelings from data.
Occasionally, I also create reactive documents. Imagine if you could tweak the numbers above and test out different scenarios yourself. Maybe you disagree with my assumption that solar panels can convert 10% of sunlight into electricity. Well, if this document were reactive, you could change that number and see how the conclusions change, live in the text.
We need feelings to give us the drive to act. But once we have decided how to act, we need effective ways to understand how our actions fit into the big picture and whether they help or harm.
By doing these kind of calculations, we can ensure that our actions are moving the world in the right direction.