Guardian: It is one of the few visible growth industries of the recession: the lobbying and PR offensive aimed at influencing how, when and even whether Barack Obama moves America towards a new low carbon economy. The battle for control over that generational shift is being waged as fiercely in the committee rooms of Congress – where the crucial climate change and energy law will be written – as in the heartland states where the changes will be felt the most. Turn on the radio in a …