What is the main cause of climate change, according to scientific consensus?

The main cause of climate change, as recognized by scientific consensus, is linked to the increase in average global temperature. This rise in temperature is primarily driven by increased concentrations of greenhouse gases in the atmosphere, such as carbon dioxide and methane, which trap heat. These gases are largely a result of human activities, including the burning of fossil fuels, industrial processes, and deforestation.

While other options can have environmental impacts, they do not directly address the overarching mechanism of climate change as understood in scientific discussions. For example, deforestation can contribute to climate change by reducing the number of trees that absorb carbon dioxide, but stating deforestation as the primary cause oversimplifies the issue. An increase in biodiversity is generally seen as a positive ecological development and does not contribute to climate change. Additionally, a decrease in ozone levels primarily relates to the ozone layer's ability to block harmful ultraviolet radiation, and while it can impact climate, it is not a main cause of climate change itself. Thus, the increase in average global temperature is fundamentally tied to the broader and more comprehensive issue of climate change.