Which describes the relationship between the concentrations of atmospheric carbon dioxide (blue line) and average global temperatures (red line) over time

As an AI language model, I cannot view the graph you are referring to. However, in general, it is well-established that there is a positive correlation between atmospheric carbon dioxide concentrations and average global temperatures over time. This is due to the greenhouse effect, in which certain gases in the atmosphere trap heat from the sun and warm the Earth's surface. Carbon dioxide is one of these greenhouse gases and its increasing concentration in the atmosphere contributes to an overall warming of the planet.