Peak coal black coal resources could last more than 200 years based on rate of extraction in 2007. This does not account for brown coal stocks. According to calculations conducted for the Hunter Community Environment Centre in Newcastle, the Australian state of New South Wales 10,600 million tonnes of coal reserves would be exhausted by 2042, based on current industry growth and extraction rates of about 3.2 per cent a year. Coal output peaked in 1913 in Britain at 287 Mt and now accounts for less than one percent of world coal extraction. 2007 extraction was around 15 Mt. According to the
Environmental impact of the coal industry This is due to the relaxation of pressure and fracturing of the strata during mining activity, which gives rise to safety concerns for the coal miners if not managed properly. The buildup of pressure in the strata can lead to explosions during (or after) the mining process if prevention methods, such as "methane draining", are not taken. In 2008 James E. Hansen and Pushker Kharecha published a peer-reviewed scientific study analyzing the effect of a coal phase-out on atmospheric CO levels. Their baseline mitigation scenario was a phaseout of global coal emissions by 2050. Under the "Business as Usual" scenario,