29 September 2016, The Conversation, Putting carbon back in the land is just a smokescreen for real climate action: Climate Council report. Just as people pump greenhouse gases into the atmosphere by burning fossil fuels, the land also absorbs some of those emissions. Plants, as they grow, use carbon dioxide and store it within their bodies. However, as the Climate Council’s latest report shows, Australia’s fossil fuels (including those burned overseas) are pumping 6.5 times as much carbon into the atmosphere as the land can absorb. This means that, while storing carbon on land is useful for combating climate change, it is no replacement for reducing fossil fuel emissions. Land carbon is the biggest source of emission reductions in Australia’s climate policy centrepiece – the Emissions Reduction Fund. This is smoke and mirrors: a distraction from the real challenge of cutting fossil fuel emissions.Land carbon Land carbon is part of the active carbon cycle at the Earth’s surface. Carbon is continually exchanging between the land, ocean and atmosphere, primarily as carbon dioxide. In contrast, carbon in fossil fuels has been locked away from the active carbon cycle for millions of years. Carbon stored on land is vulnerable to being returned to the atmosphere. Natural disturbances such as bushfires, droughts, insect attacks and heatwaves, many of which are being made worse by climate change, can trigger the release of significant amounts of land carbon back to the atmosphere. Changes in land management, as we’ve seen in Queensland, for example, with the relaxation of land-clearing laws by the previous state government, can also affect the capability of land systems to store carbon. Burning fossil fuels and releasing CO₂ to the atmosphere thus introduces new and additional carbon into the land-atmosphere-ocean cycle. It does not simply redistribute existing carbon in the cycle. Read More here
Tag Archives: carbon capture
24 March 2016, Climate News Network, Humans tilt climate books out of balance. Greenhouse gases from cattle, fertilisers, manure and agriculture mean that human activities have turned the land and soil into part of the global warming machine. In the great book-keeping of climate change, scientists have just discovered a big mistake. They have been wrong, they now think, to count on the mountains, the plains, the forests and the grasslands as an agency that slows climate change by absorbing carbon dioxide. It does absorb carbon dioxide. But the chilling news is that the soil itself may be making the world warmer. That is because humans have changed the way the landscape and its living things works, and now – thanks to those other greenhouse gases, methane and nitrous oxides, from cattle, fertilisers, manure and agriculture – the terrestrial biosphere is actually accelerating climate change. Twenty-three scientists from 16 laboratories and institutions report in Nature journal that they re-examined the sums on which climate forecasts depend. They concluded: “We find that the cumulative warming capacity of concurrent biogenic methane and nitrous oxide emissions is a factor of about two larger than the cooling effect resulting from the global land carbon dioxide uptake from 2001 to 2010.” Read More here
17 February 2016, Climate News Network, Carbon capture could be costly and risky. Attempts to remove carbon dioxide from the atmosphere and store it safely are all potentially costly gambles with the current technology, scientists say. There’s bad news for those who think that carbon dioxide can be removed from the atmosphere and stored deep in the Earth’s rocks. Even if carbon capture is possible, sequestration in the rocks is fraught because the gas can find multiple ways to escape, according to a report by a team from Penn State University, US, in the International Journal of Greenhouse Gas Control. Carbon dioxide is not the only greenhouse gas, but it is the one that drives global warming. It escapes from power station chimneys and motor exhausts. Back in the 18th century, the air contained 280 parts of CO2 per million, but now the level has just reached 400 parts per million. In the same period, the average global temperature has risen by 1°C and will go on rising, to make climate change an increasing hazard. Switch to renewables Last December, 195 world leaders agreed in Paris to take action aimed at containing warming to – if possible – 1.5°C. Climate scientists warn that the world must switch to solar power, wind and other renewable sources. But some think that if the exhaust emissions could be trapped and stored, humans would be able to get a bit more value from their fossil fuel investments. Others see it as the only way of avoiding 2°C of warning − the agreed international safety limit prior to the Paris climate summit. The problem is that nobody is confident that carbon can be captured on a sufficient scale. “Removal of CO2 will be expensive and is currently unproven at the scale needed – so it would be much better to reduce emissions as rapidly as possible” Some projects have been abandoned, and others suggest that the problem is that not enough has been spent on the research. But the Penn State team looked at a different aspect: whether CO2 could be buried and forgotten. So they tested laboratory reactions that involve sandstone and limestone – two of the sedimentary rocks found most often in geological strata – and water and carbon dioxide. Read More here
17 February 2016, Eureka Alert, Assessing carbon capture technology. Carbon capture and storage could be used to mitigate greenhouse gas emissions and thus ameliorate their impact on climate change. The focus of this technology is on the large-scale reduction of carbon emissions from fossil-fuelled power plants. Research published in the International Journal of Decision Support Systems investigates the pros and cons, assesses the risks associated with carbon capture and provides a new framework for assessing the necessary technology. John Michael Humphries Choptiany formerly of Dalhousie University in Nova Scotia and now at the Food and Agriculture Organization of the United Nations in Rome, Italy, together with colleagues at Dalhousie, Alberta Innovates – Technology Futures (AITF), and G BACH Enterprises Incorporated, explain how they have adopted information from the environmental, social, economic and engineering fields to create their assessment framework, which incorporates utility curves, criterion weights, thresholds, decision trees, Monte Carlo simulation, critical events and sensitivity analysis. “Climate change is one of the most serious threats facing humankind,” the team reports, “Carbon capture and storage (CCS) includes a suite of technologies and processes with the goal of mitigating climate change by capturing and storing anthropogenic CO2 from various emitters, including fossil-fuelled power plants, in geological reservoirs.” The Intergovernmental Panel on Climate Change (IPCC) has recognized that CCS should be one component of our response to carbon emissions and climate change, but there are many different approaches that could be taken, all with various risks. Read More here