A common finding of cost–benefit analysis is that the optimum level of emissions reduction is modest in the near-term, with more stringent abatement in the longer-term (Stern, 2007:298; Heal, 2008:20; Barker, 2008). This approach might lead to a warming of more than 3 °C above the pre-industrial level (World Bank, 2010:8). In most models, benefits exceed costs for stabilization of GHGs leading to warming of 2.5 °C. No models suggest that the optimal policy is to do nothing, i.e., allow "business-as-usual" emissions.