A group of scientists want to find out how the world’s forests will respond to higher levels of carbon dioxide. By the middle of the 21st century, levels of carbon dioxide in the atmosphere are expected to have risen significantly, which is why researchers are keen to find out how effective the Earth’s forests will be as carbon sinks. They’re now using the Staffordshire forest in England as an outdoor laboratory for their carbon impact experiment.
The Industrial Scale Carbon Experiment
Professor Rob Mackenzie from Birmingham University is the lead scientist for this carbon impact experiment. He is part of a team of scientists that are testing the effects of high carbon dioxide levels on the Earth’s forests. The experiment being held in the Staffordshire forest is the first of its kind to be conducted in Europe. There are currently three other countries, apart from England, that are conducting similar experiments.
Mackenzie chose Staffordshire forest (also known as Mill Haft) because it is thought to have been consistently covered with trees for over 300 years. This 25 hectare woodland is mostly covered in English Oak (Quercus robur) that are between 160 and 180 years old.
Scientists have installed 25 meter high masts beside trees to pump out high levels of carbon dioxide throughout the forest. They will pump out 550 parts per million (ppm) levels of carbon dioxide to see what the effects will be on the trees, their leaves, the soil, insects and diseases. They’ve also encircled the Staffordshire forest with a 3 meter high anti-climb fence and lined the forest with silver snake-like tubes.
Mackenzie says that “the impact of changing CO2 should show up in the leaf chemistry of exposed trees within days, and in the soil within weeks.” He predicts that within three years they should see changes in stem growth, canopy structure and other structural forest elements in the areas of the forest exposed to higher CO2 levels.
Forests as Carbon Sinks
Researchers want to find out how effective the Earth’s forests will be as carbon sinks as CO2 levels continue to increase. Trees are estimated to store between a quarter and a third of the carbon emitted from the burning of fossil fuels. Some scientists believe that when CO2 levels rise significantly, trees will fix more CO2 as a plant fertilizer into their roots, trunks, and for other organic matter in the soil. Mackenzie agrees, but he also told BBC News that “we are quite sure that there will be other things that will start to limit that. Rising temperatures will (also) change the ability of plants (to absorb CO2) - they are adapted to current temperatures.”
Professor Ranga Myneni from Boston University has conducted studies that reveal a positive fertilization effect and higher water use efficiency with increased levels of CO2. But they also found that these positive effects diminished over time. It’s unclear how much of the information gathered from such experiments translates to the real world, but it’s important to take note of their findings.
It’s crucial that scientists and citizens do not rely heavily in this fertilization effect as the answer to global warming. The fertilization effect should not be an excuse for humans to keep pumping out fossil fuels into the atmosphere. If anything, optimists believe that the forests and oceans are helping humans buy time to lessen their reliance on fossil fuels and help address the issue of climate change. Carbon impact experiments can provide us with insight on increased levels of CO2 in the atmosphere and its effects on forests, but it is up to citizens to take action and help reduce the amount of CO2 being pumped into the atmosphere.