Well, they _do_ if the tax is not coupled with a dividend.
To a fist approximation, the carbon tax you pay will be a fixed fraction of all the money you spend in daily life.
Poor people spend essentially all their income every month. The better off you are, the lower a fraction of your income you have to spend each month.
So a poor person will pay X% of their income, while a well-paid software professional might pay X% of 25% of her income.
That's regressive.
But a carbon fee & dividend, taken as a whole, is progressive, rather than regressive, because the poor receive a dividend in excess of the fee they pay, while the wealthy pay more fees but receive the same dividend.
To a fist approximation, the carbon tax you pay will be a fixed fraction of all the money you spend in daily life.
Poor people spend essentially all their income every month. The better off you are, the lower a fraction of your income you have to spend each month.
So a poor person will pay X% of their income, while a well-paid software professional might pay X% of 25% of her income.
That's regressive.
But a carbon fee & dividend, taken as a whole, is progressive, rather than regressive, because the poor receive a dividend in excess of the fee they pay, while the wealthy pay more fees but receive the same dividend.