The political urgency of climate change means we need to correctly diagnose the immediate causes of it. Economic growth is a principal factor. However, there are sharp disagreements over how growth matters and how it should be addressed. Leading establishment institutions call for sustainable “green growth” while other, more radical advocates call for “de-growth.” Both responses are insufficient. In this chapter, I suggest we focus on capital accumulation. Accumulation depends on increasing the rate of profit, largely through exploiting labor, in order to continuously reinvest these surpluses. I empirically show that these measures – the profit and exploitation rates – are strongly correlated with harmful greenhouse gas emissions over time. Accumulation is therefore a more direct driver of greenhouse gas emissions. It also suggests that addressing the unequal social relations in this process through social solidarity is a constructive way to also mitigate harmful emissions.