This paper analyzes the determinants of economic growth in coastal countries and discusses their potential consequences on mangrove blue carbon (BC). We use a Bayesian averaging of classical estimates technique to fit models reflecting alternative theories to 1960–2009 data on 23 specific coastal countries with high mangrove blue carbon climate change mitigation potential, BC countries, and 83 generic worldwide countries, WW countries. We find that the neoclassical, demography, macroeconomic policy, and natural capital theories perform well in explaining growth in BC countries. In contrast, investment in physical capital and proxies for macroeconomic policy and natural capital theories are found not to be good predictors of growth in the WW sample. These results point to the critical problem of existing and potentially increasing anthropogenic pressure that coastal areas with BC are and can be subject to due to land conversion for agriculture, aquaculture, farming and other run-offs, marine resources exploitation, uncontrolled sewage, marine resources direct exploitation, and coastal constructions and public works related to natural capital exports. This grim picture of coastal countries raises the important policy questions of whether central governments ought to give local policy makers and communities incentives to promote nature-based solutions to climate change mitigation and the extent to which international financial institutions should provide support for such initiatives in developing countries.