I am very disappointed by the US Supreme Court. In a recent judgement, reported in this BBC story, they blocked the US government's attempt to toughen the Clean Air Act.

The US government had attempted to toughen the rules on emissions of toxins, including mercury. The court ruled that the government must factor in the costs of compliance. This has all the hallmarks of industrial lobbying, and is extremely one-sided.

If the court thinks that cost has to be included, then benefits must be given equal weight, even though it is very difficult to do for environmental issues. Cost/benefit analysis is a standard tool used by business and government to assist in decision making, comparing the costs of making a change to the benefits of that change, but to succeed it requires that everything can be evaluated in terms of money. Measuring the benefits of a cleaner environment in terms of money is hard; indeed it can be hard to quantify environmental improvements even in environmental terms: exactly how much will cleaner air improve the amount of toxins that humans and other life are exposed to (and what are the benefits in terms of quality and duration of life, and productivity) and how quickly?

Nevertheless, we have to try. Ignoring these issues is what got our planet into the state it is in today. If we don't have the science to get accurate estimates of the benefits, then we need to at least make some rough estimates.