Carbon dioxide levels refer to the concentration of CO2 in the atmosphere, measured in parts per million (ppm). These levels fluctuate naturally due to processes like respiration, decomposition, and ocean absorption. However, human activities, particularly the burning of fossil fuels and deforestation, have significantly increased CO2 concentrations since the Industrial Revolution. High levels of carbon dioxide contribute to the greenhouse effect, trapping heat in the atmosphere and leading to global warming. Monitoring CO2 levels is crucial for understanding climate change and its impacts on ecosystems, weather patterns, and human health.