Data of CO2 concentration in atmosphere, from . The range is from January 1958 to October 2014. In the image we see the recurrence plot. The global annual mean concentration of CO2 in the atmosphere is currently rising at a rate of approximately 2 ppm/year and accelerating . This acceleration is shown by the recurrence plot, where colours are narrowing towards the diagonal line. Tans, P. & Keeling R. (2014). Trends in atmospheric carbon dioxide, Oceanic & Atmospheric Administration (NOAA). At www.esrl.noaa.gov/ gmd/ ccgg/ trends/
About 1970, the oil production and import of US had a sharp peak (data from Ref.12). Note how the corresponding recurrence plot evidences this peak.
 Vv.Aa. (2014). U.S. Energy Information Administration (EIA), at www.eia.gov/petroleum/