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: Agriculture
21 September 2016, Climate News Network, Dire climate impacts go unheeded. New scientific studies address lack of awareness of the adverse economic, social and biodiversity effects that climate change is already having. The social and economic impacts of climate change have already begun to take their toll – but most people do not yet know this. Politicians and economists have yet to work out how and when it would be best to adapt to change. And biologists say they cannot even begin to measure climate change’s effect on biodiversity because there is not enough information. Two studies in Science journal address the future. The first points out that historical temperature increases depress maize crop yields in the US by 48% and have already driven up the rates of civil conflict in sub-Saharan Africa by 11%. Economic growth Hot weather in future could slow global economic growth rates by nearly 0.30 percentage points per year. Almost as surprising, according to Solomon Hsiang, principal investigator in the Global Policy Lab at the University of California, Berkeley, is that nobody seems to be aware of these facts. “People get so used to hot days, since they happen all the time, that they never stop to consider that those days are costing them,” Professor Hsiang says. “But if people used different technologies or organised their lives differently to adapt to their climate, then we might be able to do dramatically better.” Read More here
30 June 2016, NASA. Why a half-degree temperature rise is a big deal. The Paris Agreement, which delegates from 196 countries hammered out in December 2015, calls for holding the ongoing rise in global average temperature to “well below 2 °C above pre-industrial levels,” while “pursuing efforts to limit the temperature increase to 1.5 °C.” How much difference could that half-degree of wiggle room (or 0.9 degree on the Fahrenheit scale) possibly make in the real world? Quite a bit, it appears. The European Geosciences Union published a study in April 2016 that examined the impact of a 1.5 degree Celsius vs. a 2.0 C temperature increase by the end of the century, given what we know so far about how climate works. It found that the jump from 1.5 to 2 degrees—a third more of an increase—raises the impact by about that same fraction, very roughly, on most of the phenomena the study covered. Heat waves would last around a third longer, rain storms would be about a third more intense, the increase in sea level would be approximately that much higher and the percentage of tropical coral reefs at risk of severe degradation would be roughly that much greater. But in some cases, that extra increase in temperature makes things much more dire. At 1.5 C, the study found that tropical coral reefs stand a chance of adapting and reversing a portion of their die-off in the last half of the century. But at 2 C, the chance of recovery vanishes. Tropical corals are virtually wiped out by the year 2100. Read More here
18 May 2016, The Conversation, Are toxic algal blooms the new normal for Australia’s major rivers? For much of this year, up to 1,700 kilometres of the Murray River has been hit by a serious outbreak of potentially toxic blue-green algae, which has flourished in the hotter-than-average conditions. After three months, the river is now recovering with the arrival of wet weather. But we are unlikely to have seen the last of these poisonous microbes. Large blue-green algal blooms are a relatively new phenomenon in inland waterways. In 1991 an algal bloom affected more than 1,000 km of the Darling River, the first time such an event had been reported in an Australian river, and one of the few times internationally. It was an environmental disaster, killing livestock and striking a telling blow against Australia’s reputation as a clean, green farming nation. The response was decisive: a state of emergency was declared, and the bloom ultimately gave rise to significant investment by state and federal governments into freshwater research, particularly in the Murray-Darling Basin. Why no emergency now? Fast forward two and a half decades to the latest bloom afflicting the Murray River, one of Australia’s most socially, economically and culturally significant waterways. The past decade has seen four similar blooms on the Murray River: in 2007, 2009, 2010 and now. Yes, they have garnered press attention, but there has not been the same call to arms that we saw when the Darling River was struck in 1991. It is almost as if such significant environmental events are now simply seen as the new normal. Why the apparent complacency? The 2007, 2009 and 2010 algal blooms on the Murray River all happened during the Millennium Drought, and hence were probably ascribed to an aberration in the weather. In reality, the situation may have more to do with how we manage water in Australia – particularly during periods of scarcity, such as the one we may well be entering now. Read More here