The data shows that CO2 levels from all the observatories have been continually rising since 1970 (Andrews, 2020). This is measured by analyzing the rate of absorption of light in an optical cavity (Tans and Thoning, 2020). The repeated ups and downs throughout the pattern is from the seasons. In the summer, plants are able to absorb the CO2 in the air as the photosynthesize thus dropping the CO2 level, while in the winter, the plants die, causing the CO2 to rise again; these repeated rises and falls of CO2 are what creates the saw-tooth pattern in the trend for each location (Fantle, 2021). This also explains why places with more consistent seasons like Samoa and the South Pole have less variation in the CO2 levels throughout the year. Nonetheless, the CO2 levels across all of the observatories have been raising at very similar rates, illustrating that CO2 levels have been increasing globally (Andrews, 2020).
CO2 is a greenhouse gas that contributes to the greenhouse effect, a natural process where infrared light is trapped in the atmosphere and raises the temperature of the Earth (Molles, 2016). Although the greenhouse effect is natural, human activities like “deforestation, land use changes, and burning fossil fuel” have increase the amount of CO2 into the atmosphere by 47%, which ‘forces’ the climate to increase to unprecedented temperatures (NASA, 2021).
Because the CO2 levels shown in the graph have been continually increasing globally, it also means that the global climate must be rising as well. This can have major consequences for the environment and for the humans living in it — such as sea level rise, increase of water-borne diseases, decline or extinction of animal and plant species to name a few (Molles, 2016). Additionally, because humans are the ones causing these CO2 and climate increases, we have understand how we are contributing to the amount of CO2 being emitted into the atmosphere so that we can limit it and attempt to slow the rate of climate change.
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