Emissions Trading Scheme is actually a very clever tax that self adjusts. EU is putting a cap on the emissions and the allowed emissions are auctioned, so that

Emissions Trading Scheme is actually a very clever tax that self adjusts. EU is putting a cap on the emissions and the allowed emissions are auctioned, so that companies must compete for smaller and smaller pool of allowances. If companies do not reduce emissions there is no limit to how high taxation can go, as the tax rate is market driven with limited supply of allowances. I think Shell may be simply in denial of the reality and/or may be hoping that political back channels will preserve status quo.