Finally we have a simple explanation of a global warming cause. The following is from then US Department of State Report - KEY UNCERTAINTIES AFFECTING PROJECTED GREENHOUSE GAS EMISSIONS
"Any projection of future emissions is subject to considerable uncertainty. In the short term (less than 5 years), the key factors that can increase or decrease estimated net emissions include unexpected changes in retail energy prices, shifts in the competitive relationship between natural gas and coal in electricity generation markets, changes in economic growth, abnormal winter or summer temperatures, and imperfect forecasting methods.
Additional factors may influence emission rates over the longer term, notably technology developments, shifts in the composition of economic activity, and changes in government policies." My summary, they still have no idea.