The position of Earth\'s continents has shifted dramatically over its history. I

Question

The position of Earth's continents has shifted dramatically over its history. Imagine that all of Earth's land mass was bunched together with approximately equal areas above and below the Equator. Assume that seasonal patterns of growth and respiration are otherwise similar, with the Northern Hemisphere's summer occurring June-August and the Southern Hemisphere's summer occurring December-February.

How will this new configuration affect seasonal swings in average global CO2??

Also, as a side question, What is an Ecological footprint? Thanks!

Explanation / Answer

The Northern Hemisphere has much more land for vegetation to grow on compared to the Southern

Hemisphere. Carbon dioxide (CO2) builds up slowly during the northern winter, when trees and

plants are dormant. Then in May everything begins to grow, and CO2 is taken out of the

atmosphere, so the levels start coming down. In October and November vegetation stops growing,

and in its dormant state it stops absorbing CO2, so the carbon in the atmosphere increases. These

levels go up and down like this every year.

Because photosynthetic activity is the cause of seasonal CO2 swings, regions with more plants

will experience larger fluctuations. Photosynthesis also occurs in the oceans, but little of this

CO2 actually moves into the atmosphere, which is why only land photosynthesizers drive seasonal

cycles. Two regions of Earth contain the majority of land plants: Northern Hemisphere continents

and the tropics that encompass, among other areas, the vast rain forests of the Amazon basin.

Near the equator, however, the seasonal variations in temperature are less pronounced. Seasonal

swings in CO2 are therefore most pronounced in the Northern Hemisphere, where the seasonal

changes in temperature result in very large differences in plant photosynthesis from summer to

winter.

Hence, due to this new configuration there will be no seasonal swings in average global CO2.

Total land mass of Earth will remain same in this new configuration. So, land for vegetation will

also remain same.

Researchers found strong seasonal CO2 fluctuations throughout the Northern Hemisphere and weaker

fluctuations near the equator and in the Southern Hemisphere. The station at Barrow, Alaska (71

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