Borrowed time
Before a transatlantic crossing, one of the first things you learn is arithmetic. Not navigation, not sail trim, arithmetic. How many days at sea, how many litres of water per day, how much food, how much fuel for the generator. You count it, you write it down, and you load exactly that. Once the coastline disappears behind you, the sum is fixed. Nobody sails out with more to give you. What is on board is what you have, until you reach the other side.
That is the first lesson of ocean racing, and it stays with you long after the race is over. You learn to respect a closed system. You learn what it feels like to watch a supply of something get smaller every day, and to know, with total certainty, that there is no shop around the corner and no one coming to top you up.
But the sum is never really fixed, because the weather is not fixed. On a big modern hundred footer, an Atlantic crossing might take nine days. On the 37 footer I sailed, sixteen days was flying low, a fast crossing for that sized yacht. Give the wind less than it owes you and that same crossing stretches out, eighteen days, twenty. My first ocean crossing, Cape Town to Rio, took twenty days, quick for a first attempt, but every one of those days still needed the same fuel for the same navigation electronics, the same instruments, because at sea your batteries need a generator and the generator needs fuel, regardless of how slow the yacht was moving.
So you ration. You cut your food, you cut your fuel, you cut whatever you can, not because rationing is comfortable, but because running out in the middle of the Atlantic is not an option. Out there, the arithmetic is survival, not preference. On that crossing, our watermaker underperformed badly, delivering considerably less than calculated. We compensated with stored bottles and the occasional rainwater we managed to collect. Nothing is guaranteed out there. Every system has a limit, and the ocean finds it.
Earth works on the same principle, except most people never do the sum, and almost nobody rations.
Every year, sometime in the summer, humanity reaches the point where we have used up everything the planet can regenerate in twelve months. In 2025 that day fell on the 24th of July. From that date until the end of December, we are not living off what the Earth produces anymore. We are living off what it cannot replace. Right now we are using resources at roughly 1.8 times the rate the planet can regenerate them, which is another way of saying we would need almost two Earths to live the way we currently live.
I know exactly what that number means, because I have lived a version of it. Cape Town to Rio, twenty days sailed, but provisioned for twenty three or twenty four, because you never know what the weather will give you. Every extra day of stores is also extra weight, working against you if you want to win. So you carry for the slow scenario while racing for the fast one. If I had burned through all of it, every category, at 1.8 times the rate I had budgeted, I would not have made it to the other side. It is not an abstract multiplier to me. It is the difference between reaching land and not reaching it.
On a yacht, if you miscalculate your stores, the crossing ends badly. There is no version where you simply keep drinking the water after it runs out. The ocean does not care about your plans, your ambitions, or your deadline. It enforces the arithmetic whether you like it or not.
On Earth, we have found a way to keep drinking after the water runs out. We call it overshoot, and we have normalised it. We do not stop consuming when the annual budget is spent. We borrow against next year, and the year after, and the year after that. It does not feel like an emergency because nothing runs dry all at once. It shows up instead as soil that gives less each season, fish stocks that thin out, forests that grow back slower than we cut them, a climate that swings harder every year. The debt is real, it is just slower than a yacht running out of water, so it is easier to ignore.
I do not think overshoot is abstract. I think it is the same problem I trained for at sea, just stretched across a much bigger yacht, with seven billion people on board instead of a small crew, and no coastline in sight to remind us the supplies are finite. Out on the ocean you cannot fool yourself about this. You feel every litre. On land, the systems are large enough and the feedback slow enough that we mistake the illusion of abundance for the real thing.
That is also where my instinct for circularity comes from. At sea you do not throw anything away without thinking twice, because what you have on board is all you get. Nothing is truly wasted, everything has a second use before it becomes rubbish. That habit does not switch off when you step back on land. I still think in loops rather than in straight lines, and it has nothing to do with what field it happens in. Fashion, materials, food, energy, whatever the industry, I am in favour of anyone who keeps something moving instead of discarding it, who gives it a new purpose instead of letting it become waste. Overshoot is what happens when a system stops thinking in loops and starts thinking in straight lines, take, use, discard, and assumes there will always be more where that came from.
I do not have a tidy answer to overshoot, and I am suspicious of anyone who claims they do. But I know what it looks like to live inside a limit that is real and non-negotiable, because I have done the maths myself, with my own hands, before every crossing, and adjusted it again when the wind turned against me. That habit, counting what you actually have, and cutting your consumption the moment conditions demand it, is not pessimism. It is seamanship. It might be the most useful thing ocean racing ever taught me, and it is the lens I now cannot help but apply to the planet we are all, quite literally, adrift on together.
