Irish botanists are part of an EU-wide initiative to reduce carbon dioxide emissions from the land, writes Kathrine Burke
Carbon dioxide is just a gas, but it is causing quite a stir in the political world. The European Union is spending millions on finding ways to manipulate land use to produce less of it. A research team at the department of botany at Trinity College Dublin led by Prof Mike Jones is involved in a pan-European effort to lower carbon dioxide levels in the air by raising carbon dioxide levels in the ground.
The issue is not a matter of obscure scientific interest, warns Jones. "Ireland has a problem," he says. "We signed up to the Kyoto agreement. It is not in force yet, but under that agreement, we have commitments to controlling our CO2 emissions. We are not meeting those. We will overshoot them and we are likely to be subject to fairly severe penalties."
The Kyoto commitment period is 2008 to 2012, and the scale of fines for non-compliance is not known yet. At the moment, industry is getting credits for reducing CO2 emissions. Soon, it will be a case of penalties for not reaching defined targets.
Jones's group is involved in a major Europe-wide project called "CarboEurope", which received €16.3 million from the European Commission. The goal is to study how carbon is fixed and released by the European land mass and how different land management can affect the carbon balance. Jones's group is studying how the absorption and release of CO2 varies in different grasslands and with different agricultural practices.
In the so-called carbon cycle, carbon dioxide is released to the atmosphere through natural chemical reactions like breathing and decomposition, and taken back out again mostly by vegetation. When carbon is fixed in plant material (or in soil, in roots or dead organic material), this delays the release of CO2 to the atmosphere. This is referred to as a carbon sink.
Oil is a carbon sink. Its carbon content has been held under the ground for millions of years. By constantly burning it we release far more carbon dioxide into the atmosphere than happens naturally. Land absorbs just 30 per cent of fossil fuel emissions, so the CO2 in the atmosphere is increasing.
The mystery is that there is a lot less CO2 in the atmosphere than there should be. A massive amount of CO2 is missing from the "balance sheet", says Jones. Some ecologists point to the oceans as the "missing sink", but oceanographers shake their heads. Whatever it is - is thought to be in the northern hemisphere, around our latitude.
"The work of this project could answer that question," Jones said. "We are taking measurements to quantify, for instance, how big a sink are grasslands in Ireland, and how big a source of CO2 are arable soils.
"Then, we want to find out if you can do things to reduce activity as a source, or to increase activity as a sink, Jones adds. "Can you manage the grassland to make it a more effective CO2 sink? Can you graze it in a particular way or cut at different intervals? Or can you grow different types of grasses to increase the amount of carbon sequestered?"
"The principle behind these measurements is that we can think about regulating the rate at which CO2 is building up in the atmosphere by increasing the size of these sinks," Jones says. "It is a massive task and won't solve the problem, but it may partly slow the process and give us time to do other things."
Jones's group is particularly interested in "low till" practices in arable farming. Normal practice is to plough deeply before sowing the crop. By ploughing and disturbing the soil, organic material is exposed to the air and decomposes, thereby adding carbon dioxide to the atmosphere.
By comparison, with low till, the soil is disturbed as little as possible. "You just disturb the surface. You don't bring deeper organic material to the surface. Therefore you potentially reduce the losses of carbon."
CarboEurope is funded under the European Commission's sixth framework programme, which covers the period 2002 to 2006. The project started last January. It involves 91 institutions from 20 European countries. UCD and UCC are also involved, and project partners across Europe use data from Mace Head in Galway, a sophisticated monitoring site for atmospheric gasses, which is partly operated by the physics department at NUI Galway.
Jones notes that his participation in CarboEurope could not have happened without funding from the EPA.