27 September 2016, Climate Central, The World Passes 400 PPM Threshold. Permanently. In the centuries to come, history books will likely look back on September 2016 as a major milestone for the world’s climate. At a time when atmospheric carbon dioxide is usually at its minimum, the monthly value failed to drop below 400 parts per million. That all but ensures that 2016 will be the year that carbon dioxide officially passed the symbolic 400 ppm mark, never to return below it in our lifetimes, according to scientists. Because carbon pollution has been increasing since the start of the Industrial Revolution and has shown no signs of abating, it was more a question of “when” rather than “if” we would cross this threshold. The inevitability doesn’t make it any less significant, though. September is usually the month when carbon dioxide is at its lowest after a summer of plants growing and sucking it up in the northern hemisphere. As fall wears on, those plants lose their leaves, which in turn decompose, releasing the stored carbon dioxide back into the atmosphere. At Mauna Loa Observatory, the world’s marquee site for monitoring carbon dioxide, there are signs that the process has begun but levels have remained above 400 ppm. Read more here
Category Archives: The Science
21 September 2016, Climate News Network, Solar cycle not to blame for warming. New research confirms that increased greenhouse gas levels − rather than solar radiation impacts − are the key factor in global climate change. European scientists have dug deep to dismiss once again the old argument that climate change might be a consequence of solar radiation rather than atmospheric chemistry. The world is warming, they confirm, because more greenhouse gases are getting into the atmosphere, and the changes in the solar cycle are not a significant factor. This is not the first such reassurance. Teams of researchers have in the last few years eliminated cosmic radiation as a factor in climate change and confirmed that sunspots, too, can be declared innocent. But in 2011, with backing from the European Co-operation in Science and Technology (COST), scientists set up their own project. They wanted to better understand the relationship between the cyclically changing patterns of sunlight and variations in climate, against a background of global warming. Solar variability The TOSCA project – which stands for “towards a more complete assessment of the impact of solar variability on the Earth’s climate”− is a co-operation involving solar physics, geomagnetism, climate modelling and atmospheric chemistry. The scientists went for a global approach, with 61 researchers from many disciplines working together to examine as many aspects as possible that might link variations in the sun’s behaviour with variations in climate. And they have summarised the story-so-far in a new report. What they identified is solar mechanisms that could alter regional climate, but none that could trigger global warming. Read More here
19 September 2016, The Conversation, Disruption over Macquarie Island calls for some clever Antarctic thinking. The fate of the Australian Antarctic Division’s research base on Macquarie Island hangs in the balance, after last week’s surprise announcement that it would close in March 2017 was followed on Friday by a suggestion that the government could yet reprieve it. Why all the fuss over a scattering of buildings on a windswept island (admittedly a UNESCO World Heritage-listed one) perched on a tectonic ridge halfway between Australia and Antarctica? Macquarie Island is the perfect natural laboratory for scientific research. Unique climate, geological, biological and astronomical measurements are collected year-round. The data is fed into many large-scale, international science programs and reports, including those published by the Intergovernmental Panel on Climate Change. It is something of an anomaly in Australia’s national Antarctic program. Unlike Heard Island, Macquarie Island lies outside the areas covered by the Antarctic Treaty and the Convention on the Conservation of Antarctic Marine Living Resources. The Tasmanian government manages the island. The buildings at the island’s north end are home to research infrastructure and accommodation for various organisations. These include the Tasmanian Parks and Wildlife Service, the Bureau of Meteorology, and the Australian Radiation Protection and Nuclear Safety Agency, which monitors the Southern Ocean for evidence of nuclear events. These buildings are increasingly exposed to ocean inundation. Read More here
11 September 2016, Climate News Network, Ocean warming intensifies power of typhoons. The violence of typhoons that devastate Asian coastal regions is being magnified by rising sea surface temperatures caused by greenhouse gas emissions. The typhoons that have slammed into the coasts of east and southeast Asia have become more violent, increasing in intensity by between 12% and 15% over the last four decades, according to a new study. And the proportion of storms that meet the classification of category 4, with winds at 200 kilometres per hour, and category 5, with gusts of more than 250 kph, has at least doubled and may have tripled. The good news for mariners is that those tropical cyclones that stay over the open ocean have not got significantly worse. The windstorms that pound the land, though, are potentially more destructive. The cause of the intensity is an overall warming of ocean surface waters in the northwest Pacific. And the researchers say: “The projected ocean surface warming pattern under increasing greenhouse gas forcing suggests that typhoons striking eastern mainland China, Taiwan, Korea and Japan will intensify further. Read more here