Understanding Long-Term Energy Use and Carbon Dioxide Emission in the USA

We compile a database of energy uses, energy sources, and carbon dioxide emissions for the USA for the period 1850-2002. We use a model to extrapolate the missing observations on energy use by sector. Overall emission intensity rose between 1850 and 1917, and fell between 1917 and 2002. The leading cause for the rise in emission intensity was the switch from wood to coal, but population growth, economic growth, and electrification contributed as well. After 1917, population growth, economic growth and electrification pushed emissions up further, and there was no net shift from fossil to non-fossil energy sources. From 1850 to 2002, emissions were reduced by technological and behavioural change (particularly in transport, manufacturing and households), structural change in the economy, and a shift from coal to oil and gas. These trends are stronger than electrification, explaining the fall in emissions relative to GDP.

本研究构建了涵盖1850至2002年美国能源消费、能源来源与二氧化碳排放的数据库。针对分部门能源消费的缺失观测值，本研究采用模型进行外推补全。整体排放强度在1850年至1917年间持续攀升，1917年至2002年则转为下行态势。排放强度上升的核心驱动因素为能源结构从木质燃料向煤炭的转型，人口增长、经济扩张与电气化进程同样起到了推动作用。1917年之后，人口增长、经济扩张与电气化进程进一步推高了碳排放总量，但并未出现化石能源向非化石能源转型的净转移。1850年至2002年间，技术变革与行为模式转变（尤其覆盖交通、制造与居民生活领域）、经济结构转型，以及能源结构从煤炭向石油与天然气的转型，共同实现了碳排放的削减。上述减排效应的力度超过了电气化进程的影响，由此解释了碳排放总量相对GDP的下降趋势。