The Engineer

Tools record trees' CO2 consumption

News

Instruments capable of measuring the ability of trees and vegetation to consume carbon-dioxide emissions have been located at sites across Dublin as part of a joint research initiative led by scientists from NUI Maynooth and University College Dublin.

The idea is to understand how different types of urban landscape cope with carbon dioxide (CO2) emissions and how planners might create ‘carbon neutral’ or more sustainable city developments in the battle against carbon emissions.

The instruments, which also measure wind, temperature, humidity and sunshine, record the CO2 concentration of the air as it passes by. They have been fixed on masts above Marrowbone Lane (an urban site with little or no surrounding trees or vegetation) and above St. Pius X Girl’s National School in Terenure (a suburban site with plenty of surrounding trees and vegetation).

A third instrument has been fixed to a mobile mast that can be located at different locations around the city. This will allow the scientists to measure the impact of heavy traffic and other key factors involved in the local carbon cycle. The instruments will be in place for three to five years.

Globally, cities contribute about 80 per cent of CO2 emissions attributed to human activities, but the nature of these emissions is rarely studied. Through this research the scientists hope to better understand the urban processes that give rise to these emissions and to determine the ability of particular urban spaces to capture CO2 after its generation.

Dr Rowan Fealy at NUI Maynooth said that until recently, these types of studies were not made in urban areas as they were regarded as far too complex. ‘As a result, scientists have tended to estimate the CO2 emissions based how much fossil fuel is used. However, measuring the flux allows us to see the link between urban landscapes and their role in generating or consuming CO2,’ he said.

‘While industry, traffic and other fossil-fuel-burning activities act as sources of CO2 emissions, trees, through the process of photosynthesis, remove carbon from the atmosphere,’ said Dr Gerald Mills from UCD. ‘In many urban areas, the absence of trees means that CO2 that might otherwise be captured in the city drifts into the wider atmosphere and contributes to global climate change.’

Funding for the project was received from the Higher Education Authority (HEA). Similar instruments to measure how urban-land use affects CO2 emissions have been installed around several major cities worldwide, including New York and Tokyo.