A study published on April 25 in the journal Nature Climate Change reveals that carbon dioxide encourages plant and tree growth that occupies a combined area twice the size of USA. While this may seem like carbon dioxide actually benefits the planet, the international team of researchers argues that these are outweighed by the negatives of too much of this greenhouse gas.
The researchers term this process as CO2 fertilisation, the enhancement of the plant growth as a result of increased carbon dioxide concentration in the atmosphere. However, this effect diminishes over time.
The researchers say that people should not think that pumping too much carbon dioxide is the key to solving climate change. Too much carbon concentration leads to negative consequences that even enhanced plant growth cannot counteract but this does not stop others from using CO2 fertilisation as a basis for arguments against cutting down carbon emission to alleviate climate change.
“The fallacy of the contrarian argument is two-fold. First, the many negative aspects of climate change, namely global warming, rising sea levels, melting glaciers and sea ice, more severe tropical storms, etc. are not acknowledged,” explains co-author Philippe Ciais. “Second, studies have shown that plants acclimatise, or adjust, to rising CO2 concentration and the fertilisation effect diminishes over time.”
Apparently, human activities that include burning oil, coal, gas and wood for energy produces 10 billion tonnes carbon dioxide into the air annually. Fifty percent of this gets stored in plants and oceans.
Green leaves produce sugars using the sunlight’s energy to mix nutrients and carbon dioxide. These sugars then become the source of food and fuel for life on the planet.
“The greening over the past 33 years reported in this study is equivalent to adding a green continent about two-times the size of mainland USA (18 million square kilometres), and has the ability to fundamentally change the cycling of water and carbon in the climate system,” adds lead author Zaichun Zhu, a researcher from Peking University in China.