Three questions to ask about any carbon-price claim

A carbon price puts a cost on emitting carbon dioxide, either through a tax or through a cap-and-trade system where emission permits are bought and sold. Claims about carbon prices are common and often hard to compare. Three questions help.

1. What is covered? A high price on a narrow slice of emissions can matter less than a modest price on a broad one. Ask which sectors and which gases are included, and which are exempt.

2. What is the level, and does it change? A price that is announced but stays low, or is regularly waived, sends a different signal from one that is predictable and rising.

3. Where does the money go? Revenue can fund tax cuts, direct payments to households, or green investment. Each choice changes who gains, who loses, and how politically durable the policy is.

Limits: carbon prices are one tool among several, and their effect depends on what alternatives people actually have, such as public transport or clean electricity.

A fair comparison between two carbon-price claims needs all three answers, not just the headline price.