The spring green may begin weeks earlier due to continually warming global temperatures. Red maples may change their habits more than other trees over the next hundred years, leafing out eight to forty days earlier than in the 20th century. Deciduous trees may receive a benefit from the changing climate, suggested biologists from Princeton University who published their study in the journal Geophysical Research Letters. With a longer growing season, broadleaved trees may be able to out-compete pine trees. Over time, this could lead to dramatic changes in the species mix of northern forests.
An earlier spring also means that trees will begin their yearly inhale of carbon dioxide earlier, which could increase the total amount of the gas that they absorb in a year.
The changing seasons cause observable global fluctuations of carbon dioxide levels. Atmospheric concentration of the gas decreases in summer when northern trees are pulling in carbon dioxide. The concentration goes back up in winter when northern trees become dormant. The seasonal zig-zag pattern can be seen in the overall rapidly increasing levels of carbon dioxide in the air.