Why is atmospheric carbon dioxide increasing?

The controversy surrounding the climate change debate centers on the influence of carbon dioxide (CO2) and what is its source. Climate warmists say it is entirely human CO2, while climate skeptics state it is other factors. In this lecture given at a European Institute for Climate and Energy (EIKE) conference in Essen, Germany back in March of this year, Professor Murry Salby explains why atmospheric carbon dioxide is increasing.