What is a result of carbon sequestration over millennia?

The correct answer highlights the process of carbon sequestration, which involves capturing and storing atmospheric carbon dioxide. When it comes to the conversion of biomass into fossil fuels, this reflects a long-term geological transformation that can occur over millennia. Biomass, when subjected to heat and pressure over extended periods, can eventually break down into fossil fuels such as coal, oil, and natural gas through a process known as thermogenesis.

This conversion is significant in the context of carbon sequestration because the process essentially locks away carbon that would otherwise remain in the atmosphere, potentially contributing to greenhouse gas accumulation. Thus, the development of fossil fuels from biomass captures carbon for long-term storage, although this stored carbon can be released back into the atmosphere through human activities like burning fossil fuels, leading to climate change concerns.

While other options touch on relevant aspects of carbon management and sustainability, they do not directly result from the long-term process of carbon sequestration. The increase in soil fertility and the reduction of greenhouse gas emissions are benefits associated with effective land use and management rather than the direct outcome of carbon sequestration spanning millennia.