Natural Decadal Climate Variability and Anthropogenic Climate Change

“There is no question that climate change is happening; the only arguable point is what part humans are playing in it” – says a quotation attributed to Sir David Attenborough, the celebrated historian of nature who brought the wonderful diversity of life on the Earth into people’s homes via television programs. This chapter explores natural climate variability at decadal timescales, it is very important to understand relationships between the two types of climate variability and change. There are exploratory efforts to analyze and understand possible interactions between decadal climate variability (DCV) and anthropogenic climate change (ACC), and the net effects of both on the observed changing climate. This chapter addresses these efforts. The scope of this chapter is to explore DCV–ACC relationships and the importance of separating and quantifying DCV-related observed changes for ACC attribution.