What is the fine-grained topic of the following text: While other oil execs defended their taxpayer-subsidized wealth and boasted that they would never have made the mistakes that led to the Deepwater Horizon blowout, Mulva spent the bulk of his testimony to call on the federal government to “establish a clear and transparent price for carbon.” Essentially, he was asking to be taxed or to have carbon fees imposed through a cap-and-trade system, which are the two primary ways of accomplishing his request, sort of a reverse shakedown. Only return the topic.
An oil executive advocating for clear carbon pricing and cap-and-trade system.