It is an honour to be invited to respond to a paper by a political philosopher who so much helped shape my own, and many others', understanding of the purpose of political philosophy in the world today. The seminal contribution under discussion here exemplifies that purpose. Yet notwithstanding its significance, Henry Shue starts his reflection on it with characteristic modesty, by suggesting it be seen in the light of two qualifications: he stands on the shoulders of giants, and he has not broken all the way through. I propose to pursue the thought that those shoulders might support us in pushing further still, if we persevere with the lines of thought that Shue has advanced, as long as we are alert to the possibility that more radical change than he discusses may be required. The problem that I shall suggest still requires further thought lies with the lack of economic incentives to tackle climate change. Shue is acutely aware that economic forces in the world are not, on the whole, pushing in the right direction regarding climate change, and yet he does find some reasons to be hopeful. In particular, he notes: 'the prices of renewable energy have declined far more rapidly than anyone expected … and the alternative technologies are growing significantly in sophistication while dropping in price'. This sounds like good news, and something potentially to build on as an exit strategy from climate disaster. Unfortunately, though, I think we may need to be cautious even about this apparent good news. The advantages flagged by Shue are both expressed in terms of reduced prices. This is a matter that one needs to examine a little more closely before simply granting an assumption that it is good news. It may be that costs are reducing because of efficiencies in technologies that produce or consume energy, which in principle is to be welcomed, but there are two general questions to consider: what of the costs of depending on those technologies-in human and in ecological terms? And what if the apparent financial gain is itself in some way deceptive or misleading? In addressing these two general questions in turn we will find that the perspective that initially influenced Shue's breakthrough may still have critical insights to yield.