Pigovian taxes, illustrated

From the BBC:

Australia introduces controversial carbon tax 

Australia has introduced its highly controversial carbon tax, after years of bitter political wrangling. 

The law forces the country's 500 worst-polluting firms to pay a AU$23 (£15; $24) levy for every tonne of greenhouse gases they produce. 

The government says the tax is needed to meet climate-change obligations of Australia - the highest emitter per-head in the developed world. 

But the opposition calls it a "toxic tax", which will cost jobs. 

The opposition also argues that the tax will raise the cost of living, promising to repeal the legislation if it wins the next election, due in 2013. 

Environmentalists have broadly backed the scheme, but there have been large public protests against it.