There is no such thing as 'strict libertarianism'; libertarianism is a spectrum (with one or more dimensions), with many internal divides including issues such

There is no such thing as 'strict libertarianism'; libertarianism is a spectrum (with one or more dimensions), with many internal divides including issues such as intellectual property. Depending on the libertarian you speak with, they may argue for a robust system of police, or a 'minarchist' government which only deals with external threats and trade issues. Auctioned cap and trade is good at achieving two objectives: 1) a strict limit, and 2) political cronyism. Most people who suggest a carbon tax are in favor of instituting it, then adjusting based on the resulting emissions. We are no better at estimating the results of any given level of pollution or emissions than we are at forecasting supply and demand response to price changes.