Good morning, and welcome.
To begin, a word about the word.
Symposium comes from the Greek Symposion: syn, together, and posis, drinking. It means, quite literally, a drinking party. In Athens, the meal would end, the tables would be carried out, the wine would be mixed with water, and then – only then – the guest would talk. Plato gave us the most famous account of one. In his Symposium, a group of men take turns speaking on a single theme. Each speech answers the one before it. Some are brilliant, some are foolish, one is delivered by a man too drunk to stand. Nobody delivers the final word.
This is the tradition we have joined ourselves to. Not a congress. Not a summit. A room in which people speak in turn, on one subject, and expect to be contradicted.
I raise this because I think we have drifted from it, and I think the drift is costing us.
In 1859, John Stuart Mill made an argument in One Liberty that has never been improved upon. To silence an opinion, he wrote, is to rob the human race. If the opinion is right, we are denied the chance to exchange error for truth. If it is wrong, we lose something almost as valuable: the clearer, livelier perception of the truth that comes from its collision with error. A truth that is never contested, Mill warned, hardens into dead dogma. It survives as a formula people recite rather than a conviction they hold.
We should be honest that some parts of our climate consensus have begun to sound like recitation.
Let me be precise about what is not in dispute. The physics is settled. The warming is real, it is anthropogenic, and it is accelerating. That is not the open question, and this is not an invitation to relitigate it.
The open question is what we do, and there our certainty is far less earned than our tone suggests.
So let me offer two propositions for this symposium to argue with.
The first is that the root of global warming is the combustion of fossil energy. Debates about consumerism, modernity, or economic growth matter, but they become secondary if the energy source beneath them remains unchanged. The mechanism is singular and physical: carbon that accumulated over hundreds of millions of years is being released over roughly two hundred. Coal, oil, and gas still supply the overwhelming majority of the world’s primary energy. Every ton of CO2 that matters traces back to that single fact. If we could change the energy source underneath everything the world produces, moves, and builds, we would address the largest part of the problem at its source. Which leads to the second, and less comfortable, proposition. If the cause lies primarily in the energy source, then treating industries one by one as though each has a separate climate problem, risks mistaking symptoms for causes.
We have developed a habit of searching for a villain each season. One year it is aviation. The next it is beef, or cruise ships, or fast fashion, or data centers. The selection is rarely proportionate to emissions and is often inversely proportional to the political cost of naming it. And the results are familiar to everyone in this room: production relocates, accounting improves, the emissions move to somewhere with weaker rules, and we declare victory over a number that has migrated rather than fallen.
Steel, cement, shipping, agriculture, computing – these sectors do not have separate carbon problems. All depend on access to low-carbon energy. They are all, underneath, applications of fossil combustion. Decarbonize energy at scale and progress becomes possible across all of them simultaneously. Address them primarily one at a time and we risk spending the century playing a game of moral whack-a-mole while the atmosphere keeps its own accounts.
There is a further cost to the villain hunt, and it is Mill’s cost. The industries we most enjoy condemning employ many of the engineers, chemists, and capital allocators we most need. When participation in this conversation begins with an assumption of guilt, we should not be surprised if some of the people with the most relevant experience decline the invitation, and that the room grows more agreeable and less useful each year.
I may be wrong about all of this. That is rather the point. If we leave this symposium with fewer certainties but better questions, we will have succeeded.
So, the wine is mixed. Speak in turn, speak plainly, and take it as a courtesy rather than as an insult when someone in this room tells you that you are mistaken. We did not come here to agree. We came here, in the oldest sense of the word, to drink together and argue well.
Thank you.
