Reconsideration of Climate Change from the Viewpoints of Greenhouse Gas Types and Time Scale

Abstract

When the Earth's surface warms and emits long-wave infrared (IR) radiation, IR active gases (e.g. CO2, CH4, etc.) effectively absorb it; CO2 is therefore one of the major challenges facing the climate research community. However, in Europe recent radiation measurement over about a decade shows that rapid temperature increase is mainly (∼65%) caused by water vapor. The following points are established through the main discussion: (i) there are a number of factors causing climate change (e.g. astronomical factors), that is, CO2 is just one of various climate drivers; (ii) the coupling complexity of CO2 with climate is enhanced by the time-scale extension; and (iii) this complexity involves various climate drivers with different cycles and magnitudes. The Earth's atmosphere has evolved over the last 4.5 billion years and still continues to evolve; thus, climate variability must be inevitable and complex. Future climate change may be drawn from the newly emerging discipline of complexity science.