Final answer:
CO2 levels are highest in May due to reduced photosynthetic absorption and lowest in September when plant uptake of CO2 is greatest. CO2 is higher in the Northern Hemisphere due to more landmass and industrial activity, which contributes to climate change, a global issue that affects weather, sea levels, and ecosystems.
Step-by-step explanation:
The CO2 concentrations are highest during May, which is in the spring season in the Northern Hemisphere. They are lowest during the autumn, around September, when the photosynthetic activity of plants is at its peak due to the growing season.
One of the main reasons CO2 concentrations are generally higher in the Northern Hemisphere is that it has more landmass and thus more vegetation and human activity. The terrestrial vegetation cycles in the Northern Hemisphere have a significant impact on CO2 levels due to the seasonal growth and decay of plant life, along with the fact that the majority of anthropogenic CO2 emissions come from the Northern Hemisphere where most of the industrial activities take place.
We should be concerned about climate change as the rising levels of CO2 and other greenhouse gases are the most significant cause of the enhanced greenhouse effect, leading to global warming. The release of CO2 into the atmosphere primarily comes from the burning of fossil fuels, such as coal, oil, and natural gas, as well as deforestation.
It is important to combat climate change because it impacts global weather patterns, leads to extreme weather events, and affects ecosystems, sea levels, and food production worldwide. Over the past millennium, CO2 levels have increased from preindustrial levels of approximately 280 ppm to over 400 ppm today, which is a major cause for concern and calls for global action.