March 2015 (CoalSwarm / Sierra Club) – Because coal is the most carbon-intensive fossil fuel and coal plants have a long lifespan, growth in coal capacity has major implications for climate stability. From 2004 to 2013, increased coal utilization outweighed all other sources combined, producing 62 percent of global carbon dioxide emissions growth from fossil fuels and cement (Global Carbon Project 2014). The International Energy Agency has found that coal use must peak by 2020 to limit global warming to 2°C above pre-industrial levels (IEA 2011), while a recent Nature study concluded that over 80 percent of current coal reserves must remain unused to allow a 50 percent chance of staying within 2°C warming (McGlade and Ekins 2015).
In 2014 the Intergovernmental Panel on Climate Change suggested that in order for there to be a better than-even chance of avoiding more than a 2°C global temperature rise, CO2 emissions between 2011 and 2050 should be limited to 870 and 1,240 billion tonnes (Gt) (Edenhofer, et al. 2014). Some scientists even argue that the 2°C target is too high to prevent irreversible climate effects like permafrost melt and sea level rise, or to protect fragile ecosystems such as coral reefs and polar regions (Rockström, et al. 2009, Hansen, et al. 2008). Future CO2 emissions over the lifetime of world’s existing infrastructure were estimated at about 500 Gt in 2009 (Davis, et al. 2010) and increased to 729 Gt in 2014 (Raupach, et al. 2014).4 This means that, unless infrastructure is decommissioned early, most of the permissible “carbon budget” is taken up by infrastructure already built.
The addition of new coal-fired capacity would significantly increase global CO2 emissions. As shown in Table 5, coal capacity currently under construction will add another 49 Gt CO2 over its 40-year lifetime. If the remaining proposed plants (Announced, Pre-permit development, and Permitted) follow the recent worldwide rate of about two projects halted for every project completed (Figure 3), another 64 Gt CO2 will be emitted.
Unless the worldwide cancelation rate for proposed projects observed since 2010 (two projects halted for each project built) can be substantially increased by advocates, capacity currently under construction or proposed will add 113 Gt of additional CO2 to the atmosphere, singlehandedly pushing emissions dangerously close to the lower end of the 2°C carbon budget (870 Gt).