Bitcoin can push global warming above 2 C in a couple decades

[Jim__]

2. My understanding is that all bitcoin transactions require mining.

My understanding is based on my reading and not having actually used or worked with bitcoin. But here's an excerpt from an article I found online that indicates to me, all bitcoin transactions require use of the blockchain, and so, miners:

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Here's how it works. When you and others announce transactions to a blockchain network, computers on that network race to solve a complicated mathematical puzzle based on those transactions. A computer that succeeds announces it to the network, and the transaction is accepted if other computers verify that none of the assets in question were already used. That's what'll keep you from selling the same concert ticket twice on a blockchain-based ticket market. (Citizen Ticket and Active Ticketing are working on this.)

But today's mining approach, called "proof of work," has huge drawbacks.

For one thing, mining works most profitably on powerful computers that consume immense amounts of electrical power. For example, bitcoin mining today uses about as much power as the country of Singapore, enough to power 4.4 million houses, according to cryptocurrency analyst firm Digiconomist. That amount is growing.

For another, transactions are relatively slow. Blockchain transactions can race past transactions that rely on middlemen and reconciliation procedures, like escrow accounts for home purchases or international money transfers. But bitcoin transactions can take about 10 minutes, which is why cryptocurrencies today aren't useful for just buying something in a store.

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My reading of that agrees with what the article in phys.org is saying.