90 companies have emitted nearly half of all GHG emissions since 1986
[Abbreviated abstract by ZA on 3.24.14] Fact:90 entities(corporations, state-owned, national producers) have created 63% percent of global GHG emissions since 1854, and nearly half of all emissions have been emitted since 1986. "and the parties responsible for the dominant sources of historic emissions are not necessarily the same as those responsible for the dominant share of current emissions"
Guardian article: http://www.theguardian.com/environment/2013/nov/20/90-companies-man-made...
"This paper presents a quantitative analysis of the historic fossil fuel and cement production records of the 50 leading investor-owned, 31 state-owned, and 9 nation-state producers of oil, natural gas, coal, and cement from as early as 1854 to 2010. This analysis traces emissions totaling 914 GtCO2e—63 % of cumulative worldwide emissions of industrial CO2 and methane between 1751 and 2010—to the 90 “carbon major” entities based on the carbon content of marketed hydrocarbon fuels (subtracting for non-energy uses), process CO2 from cement manufacture, CO2 from flaring, venting, and own fuel use, and fugitive or vented methane. Cumulatively, emissions of 315 GtCO2e have been traced to investor-owned entities, 288 GtCO2e to state-owned enterprises, and 312 GtCO2e to nation-states. Of these emissions, half has been emitted since 1986. The carbon major entities possess fossil fuel reserves that will, if produced and emitted, intensify anthropogenic climate change. The purpose of the analysis is to understand the historic emissions as a factual matter, and to invite consideration of their possible relevance to public policy."
Richard Heede, "Tracing anthropogenic carbon dioxide and methane emissions to fossil fuel and cement producers, 1854–2010," Climatic Change, January 2014, Volume 122, Issue 1-2, pp 229-241,10.1007/s10584-013-0986-y, Accessed on March 24, 2014. http://link.springer.com/article/10.1007/s10584-013-0986-y/fulltext.html
[verified 4/15/14]