If deforestation continues unabated, the Keeling Curve would likely show an even steeper upward trend. Forests act as major carbon sinks, absorbing vast quantities of CO₂ from the atmosphere. Their destruction not only halts this absorption but also releases stored carbon when trees are burnt or left to decay. As a result, more CO₂ would accumulate in the atmosphere, exacerbating the greenhouse effect. With fewer trees to balance out the CO₂ emissions from human activities, we would see a more rapid and pronounced increase in atmospheric CO₂ levels as reflected in the curve.

While the Keeling Curve's seasonal fluctuations are primarily driven by the Northern Hemisphere due to its vast land mass and vegetative cover, the Southern Hemisphere does play a role. The Southern Hemisphere, with its predominant ocean cover and lesser land area, has a more muted photosynthetic activity variation. Consequently, it doesn't cause significant seasonal dips and peaks in global CO₂ levels. However, it acts as a stabilising force, moderating the extremes and ensuring that global CO₂ levels don't fluctuate as drastically as they would if only the Northern Hemisphere's influence was considered.

Yes, while the Keeling Curve specifically tracks atmospheric CO₂, there are other data sets and curves that monitor different greenhouse gases, such as methane (CH₄) and nitrous oxide (N₂O). For instance, methane measurements from ice cores and modern monitoring show its levels and fluctuations over time. Methane, despite being present in smaller quantities than CO₂, has a much higher global warming potential, making its tracking equally crucial. Similarly, nitrous oxide, primarily resulting from agricultural activities, is also monitored, given its role as a potent greenhouse gas. Monitoring these gases is vital for understanding the broader impact on global climate change.

Terrestrial and marine ecosystems display distinct carbon flux patterns. Terrestrial ecosystems rely heavily on plants and trees that absorb CO₂ through photosynthesis. In contrast, marine ecosystems, especially the upper layers, rely on phytoplankton for photosynthesis. While trees store carbon for decades to centuries in the form of wood, phytoplankton have a shorter lifespan, meaning carbon storage in the oceans is more temporary. Additionally, oceans act as direct carbon sinks, dissolving significant amounts of CO₂ from the atmosphere. The dissolution of CO₂ in oceans leads to the formation of carbonic acid, which contributes to ocean acidification, a separate concern for marine life.

The Mauna Loa Observatory in Hawaii was strategically chosen for its unique geographical position and minimal local influences. Situated at a high altitude and in the middle of the Pacific Ocean, the observatory is far removed from large land masses and urban pollution. This location ensures that the measurements are representative of global CO₂ levels rather than localised spikes due to human activities. Moreover, the mountain's altitude and consistent wind patterns allow for the sampling of well-mixed air, making the data collected more consistent and less influenced by short-term fluctuations.