Dr Jacqueline Rowarth: Climate change, confusion, and hot air
Parliamentary Commissioner for the Environment Simon Upton's report says we cant plant our way out of the impact of GHG emissions. File photo / Alan Gibson Opinion: There are no easy answers to New Zealand or the Worlds GHG emissions but is there too much hot air and confusion surrounding climate change? Dr Jacqueline Rowarth takes a closer look at our carbon footprint. Too much hot air surrounding climate change? Confused by all the reports on solutions from planting trees, to electric vehicles, and solar panels? For those seeking facts, Sustainable Energy Without the Hot Air provides them and is free on the internet. Professor David Mackay (RIP), then Chief Scientific Adviser to the UK Department of Energy and Climate Change, published the book in 2009. In it, he explains clearly that a lifetimes wood to fix a carbon footprint from an average developed country person would occupy 1000 cubic metres five times, he estimates, the volume of an average house. That is the space needed for every person, to be stored forever. If anybody proposes using trees to undo climate change, he wrote, they need to realise that country-sized facilities are required. I dont see how it could ever work. The Parliamentary Commissioner for the Environment (PCE) Simon Upton agrees. He has done the calculations for New Zealand, and in his report released at the beginning of October, he confirms that we cant plant our way out of the impact of greenhouse gas (GHG) emissions. He has also explained the importance of methane and the long tail of its effect a half-life of 7-8 years means that only about 60 per cent has gone in twelve years, and the impact is still hanging around after several decades. Knowing the impossibility of neutralising the GHG effect of fossil fuels or animals by growing trees, the agricultural community has been focused for some time on creating low-carbon products and developing research and technologies to assist in lowering emissions even further. Trials to identify efficient management of soil, pasture quality and animal production were underway in the mid-1930s. Dairy cow breeding has gained efficiencies of approximately 1 per cent a year since the 1990s. Research into GHG was brought together in 2009 and accelerated under the aegis of the New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC). Increased investment in GHG research, announced in the 2022 budget, and the establishment of a Joint Venture partnership is designed to accelerate developments even more rapidly. The problem is that science is generally incremental. Throwing money at the challenge in the hope of achieving rapid results, as occurred for Covid, is a long shot coronaviruses have been the subject of research for years, and much was known. Further, Covid hasnt gone away. What the vaccinations have done is reduce the seriousness of impact by reducing the effect on individuals and reducing the spread. There are parallels in agriculture. Lower methane sheep are now a reality and vaccines, feed additives and inhibitors continue to be investigated. Of interest (and concern) is that the products touted to work overseas are doing so in a modified environment (housed animals on total mixed rations, for instance). In contrast, New Zealands pasture-based systems are as close to natural as possible (but without predators and with food despite drought and flood) hence the context is different for the additives. Improved management of fertiliser to improve nutrient use efficiency (NUE) globally was suggested in a report released last month by the International Fertilizer Association (IFA). NUE is key to reducing emissions per kg of food produced. Once again New Zealand is at the forefront. The 4R strategy (Right time, Right form, Right amount and Right place), enabled by the ever-improving technologies deployed by fertiliser companies, is part of the reason that New Zealand has achieved production of low-carbon products . The result for New Zealand should be that companies declaring their goals of being carbon neutral by 2050 (or whatever year), should be sourcing more New Zealand products to help. At the moment their focus has been planting trees (e.g., McDonalds ) as their major contribution, while encouraging cereal farmers to adopt rotational cropping involving no-till and cover crops to build up soil carbon. Often overlooked is the fact that increasing soil organic matter requires significant amounts of nutrients, such as nitrogen and phosphorus, to form stable organic compounds. Listen to Jamie Mackay interview Dr Jacqueline Rowarth on The Country below: Further, there are natural limits on the amount of carbon that soils can hold, and New Zealand already has high organic matter in soils which could limit further increase (and is under investigation). In short, there are no easy answers to New Zealand or the Worlds GHG emissions. PCE Simon Upton has stated that We cannot simply plant our way out of this problem, just as we cant plant our way out of burning fossil fuels. Fossil fuel is the real challenge. New Zealand already has the information that the cut in fuel tax resulted in increased fuel emissions . Professor Mackay calculated that the price for carbon would have to be US$900 before an impact on UK driving was apparent. What would the price have to be in New Zealand? And why does the world continue to allow competitions where vehicles drive very fast, round and round burning fossil fuel while they do so? Rationalising motorsports as improving performance and safety could just be more hot air. - Dr Jacqueline Rowarth, Adjunct Professor Lincoln University, has a PhD in Soil Science (nutrient cycling) and is a Director of Ravensdown, DairyNZ and Deer Industry NZ. The analysis and conclusions above are her own. jsrowarth@gmail.com Phil Duncan, Finn Ross, Corina Jordan and Matt Holden.