What describes the daily record of global atmospheric carbon dioxide concentration initiated in the 1950s?

The daily record of global atmospheric carbon dioxide concentration, first initiated in the 1950s, is known as the Keeling Curve. This continuous measurement provides essential data on the levels of carbon dioxide in the atmosphere, showcasing a clear upward trend that reflects rising global CO2 emissions. The Keeling Curve is significant because it has been pivotal in understanding human impact on the environment through fossil fuel combustion and deforestation. It visually represents seasonal variations as well as long-term trends in carbon dioxide levels, which are critical for climatology and environmental science.

The other options refer to different concepts: the COP21 report pertains to international climate agreements made at the 2015 Paris Climate Change Conference, the Maurer graph isn't a recognized term within the context of atmospheric studies, and a greenhouse gas inventory involves the quantification of emissions from various sources rather than a continuous measurement over time. The Keeling Curve stands out as a fundamental dataset in the study of climate change.