WA graingrowers will be the focus of a three-year research project investigating how much their cropping operations contribute to greenhouse gas emissions.
The new project, launched by Greenhouse Task Force chairman Francis Logan at the Agriculture Department in South Perth last week, encompasses a wheat-to-bread life cycle assessment (LCA) of greenhouse gas emissions in WA.
Mr Logan said the project, funded by the Department, Grains Research and Development Corporation (GRDC) and Australian Greenhouse Office (AGO), would also meet a key commitment of the state's recently released Greenhouse Strategy.
Agriculture is estimated to contribute about 30pc of Australia's greenhouse gas emissions, with nitrous oxide believed to make up a third of these emissions, mainly through fertiliser and soils.
Mr Logan said the project would determine accurate estimates of nitrous oxide emissions, which had 300 times the impact on global warming as an equivalent weight of carbon dioxide.
He said 310t of carbon dioxide equivalent was produced for every tonne of nitrous oxide, while one tonne of methane gas produced 21t of carbon dioxide equivalent.
Mr Logan said the wheat industry was not being researched to put a cap on greenhouse gases, but was singled out because it was an unknown quantity.
"Based on the understanding of nitrous oxide from the WA grains industry, it is calculated as being a significant contributor to the nation's greenhouse gas emissions," he said.
"However, a review of the evidence suggests there are probably overestimates as most knowledge of nitrous oxide emission rates is based on studies in Europe and the USA.
"WA produces around 45pc of Australia's crop, and at the moment there has been no research undertaken in WA to determine the level of nitrous oxide emissions from cropping.
"The project will provide a life cycle analysis of greenhouse gas emissions from wheat to bread and will increase knowledge on nitrous oxide emissions to increase nitrogen fertiliser efficiency, profitability and minimise greenhouse gas emissions.
"On-farm estimates are therefore important to ensure emissions from WA agriculture are properly represented in the national greenhouse gas emission accounts."
It is estimated 1.25 per cent of nitrogen fertilisers gets converted to nitrous oxide.
Mr Logan said that scientists suggested emissions needed to be reduced by 60pc by 2050 to avoid dangerous climate change, and that WA should contribute to the global effort to reduce greenhouse gas emissions.
It is believed conditions in WA's grainbelt could be less conducive to nitrous oxide emissions than other areas because nitrous oxide production is favoured when soils are warm, moist and have high levels of organic matter and nitrate.
But in the WA grainbelt, the soil is moist, the temperatures are low and cropping soils are low in nitrate and organic matter.
The WA research project would include use of German-made sampling and measuring equipment that can more accurately monitor varied greenhouse gas emissions.
Mr Logan said the 30pc of greenhouse gases produced by agriculture in WA were second only to energy, which contributed to almost 70pc.
The emissions from energy were largely due to the production from the state's electricity grid.
Mr Logan said the 2.8pc increase in WA's greenhouse emissions each year were due to economic growth and expansion of stationary energy to generate more electricity.
However, he said WA, which had transferred 60pc of its power generation to gas, was better placed than eastern Australia, which relied on coal-fired power stations to generate 70pc of its electricity.
He said that in other states, research was also being carried out on methane gas emissions produced by livestock.
While Australia had one of the highest per capita greenhouse gas emissions in the world, it only contributed to 1pc of total global emissions.
"Of this WA contributes around 12pc of national emissions and has the second highest per capital emissions in the country behind the Northern Territory," Mr Logan said.
Results from the project will be used to refine greenhouse gas emission estimates for the national greenhouse gas inventory, which is Australia's estimate under the Kyoto Protocol.
The greenhouse gas project launch was told that by the end of the century, the earth's surface temperature was predicted to rise by 6oC.
This was more than the temperature change that had occurred since the ice age or in the past 400,000 years.
AGO senior policy officer Dr Bill Slattery said there were sceptics about this forecast but one thing was certain: temperatures were rising.
"We are moving to a region well outside what we have seen for some time," he said.
Dr Slattery said surface temperatures had oscillated at around zero until the 1920s, when it started to rise, and in the 1940s, coal-generated power stations accelerated carbon dioxide emissions which led to higher global temperatures.
He said sulphur dioxide (SO2)levels high in coal emissions had put a cap on global surface temperatures from the 1940s to 1980s, but when sulphur dioxide was scrubbed from coal emissions due to acid rain, surface temperatures rose again.
Dr Slattery said the greenhouse gas project may well find that major contributors of greenhouse gas were not farms, but other areas of the wheat-to-bread life cycle.
He said Australian and New Zealand researchers were also evaluating the amount of methane emissions from livestock enteric fermentation.
Nitrous oxide is estimated to make up 27pc of agricultural-produce greenhouse gases, of which 69pc is believed to come from soils.
However, methane emissions make up 73pc of agriculture's greenhouse gases with 95.5pc due to enteric fermentation.