2 added 14 characters in body edited Dec 20 '14 at 12:02 user889 The respiration of plants is not evenly distributed through seasons since the northern and southern hemisphere have a different amount of land and plants. The southern hemisphere has far less land. In the northern winter, the carbon released increases and then by ~May the northern hemisphere has enough carbon uptake (due to increased photosynthesis) to cause a dip in the CO2$$\ce{CO2}$$ record. Then summer in the north ends... autumn commences, and net CO2$$\ce{CO2}$$ starts to rise again. The respiration of plants is not evenly distributed through seasons since the northern and southern hemisphere have a different amount of land and plants. The southern hemisphere has far less land. In the northern winter, the carbon released increases and then by ~May the northern hemisphere has enough carbon uptake (due to increased photosynthesis) to cause a dip in the CO2 record. Then summer in the north ends... autumn commences, and net CO2 starts to rise again. The respiration of plants is not evenly distributed through seasons since the northern and southern hemisphere have a different amount of land and plants. The southern hemisphere has far less land. In the northern winter, the carbon released increases and then by ~May the northern hemisphere has enough carbon uptake (due to increased photosynthesis) to cause a dip in the $$\ce{CO2}$$ record. Then summer in the north ends... autumn commences, and net $$\ce{CO2}$$ starts to rise again. 1 answered Dec 20 '14 at 4:06 farrenthorpe 8,85411 gold badge3636 silver badges7777 bronze badges The respiration of plants is not evenly distributed through seasons since the northern and southern hemisphere have a different amount of land and plants. The southern hemisphere has far less land. In the northern winter, the carbon released increases and then by ~May the northern hemisphere has enough carbon uptake (due to increased photosynthesis) to cause a dip in the CO2 record. Then summer in the north ends... autumn commences, and net CO2 starts to rise again.