I think this is wishful thinking. It'd be neat if there was incentive on both sides of the debate, to bet both against and for the idea that climate change will happen. Unfortunately that's not how it is: the real direction of the change in climate will be the most profitable option, and that's where investors will flood. And yeah, that might cause a self-fulfilling prophecy (incentivizing and accelerating climate change), but that's just how it is, that's where we are. Maybe we can try to spread false ideas like yours to make investors think it's good to invest on both sides, but I don't have much faith in its potency to make real impact.

Bookies and casinos are set up so thatvit is mathematically impossible not to win.

futures originated from commodities trading, where you wanted to lock in the price of a ton of corn or wool or whatever because you fear the price will go up.

you don’t need them for currency arbitrage. you just need very fast connections to multiple currency markets, low transaction costs, and mispriced exchange rates.

it’s riskless because the money itself is mispriced and you can buy it for one price (in your own currency) and sell it for another all in one transaction. you get the difference for free. that’s what makes it riskless and that’s what makes it arbitrage.

keep reading those investopedia articles, it’s all in there somewhere!

Bookies make money because they run the game.

I think you’re specifically thinking of covered interest rate arbitrage, in which a trader borrows in one currency at a cheap rate, lends in another currency at a more expensive rate and uses a currency forward to hedge out the exchange rate risk, netting the rate differential in the process. It’s not truly ‘arbitrage’ in the formal sense;there are still some notable risks in such a trade.