A criticism is that the BRIC projections are based on the assumptions that resources are limitless and endlessly available when needed. In reality, many important resources currently necessary to sustain economic growth, such as oil, natural gas, coal, other fossil fuels, and uranium might soon experience a peak in production before enough renewable energy can be developed and commercialized, which might result in slower economic growth than anticipated, thus throwing off the projections and their dates. The economic emergence of the BRICs will have unpredictable consequences for the global environment. Indeed, proponents of a set carrying capacity for the Earth may argue that, given current technology, there is a finite limit to how much the BRICs can develop before exceeding the ability of the global economy to supply.