There appears to be confusion among those interested in Modern Monetary Theory (MMT) as to what the implications for a green transition that will fasttrack the transition to renewable energy will require by way of government. I regularly see statements that government deficits will have to be ‘massive’ for extended periods because the private (for profit) market entities will not move fast enough to deal with the climate emergency in any effective way. The confusion inherent in these claims is that they fail to separate the ‘size’ of government from any particular ‘net spending’ (deficit) recorded by government. The two outcomes are quite separable and have to be if government action is to achieve sustainable outcomes, not only in terms of environmental goals but also price stability goals. So let’s work all that out. Failing to do so, leads MMT activists to make claims that open them up to criticism from those who understand the point I am making but have different ideological agendas. So they make erroneous claims such that ‘MMT just advocates big deficits’, or that ‘MMT thinks that deficits do not matter’. But they have been lured into that position, in part, by the social media behaviour of some MMT activists.