Human Respiration is Not a Source of Carbon Emissions

That's not a problem. The CO2 that's released by humans (and animals) is produced by metabolising carbon from food, and the food comes from plants that have been grown recently. During their growth, the plants have absorbed an equivalent amount of CO2 from the atmosphere. Even when eating meat, the animals are typically only a few years old and were fed on recently grown plants. In contrast, the cars run on fossil fuels that are hundreds of million years old.

 Conclusions of the IPCC

This IPCC finding makes several different assertions, each of which is worth considering in turn. First, it claims that atmospheric concentrations of greenhouse gases like CO2 are increasing, and as a result of human activity. This is a matter of simple observation. Many industrial processes, particularly the use of fossil fuels, produce CO2 as a by-product.18 Because CO2 remains in the atmosphere for a long time, its concentrations have been rising: from about 315 parts per million (ppm) wh...