17 August, Climate News Network, Andes’ migrating trees are moving towards extinction. Highland tree species in the Andes are decreasing as global warming caused by greenhouse gas emissions forces lowland varieties to move upwards into cooler climes. Scientists have known for years that, in a warming world, many living things try to move uphill to seek survival where the air is cooler. But new research provides a dire warning of the risks for those unable to move fast enough. Unlike animals, trees and other sorts of vegetation cannot move quickly to escape the heat. And for some of them, it seems, there is no survival option available. They simply die. A study published in the Proceedings of the National Academy of Sciences reports that the number of highland tree species in the Andes mountains of South America is decreasing as lowland trees move up the slope to avoid the rising temperatures and changing rainfall patterns. The results suggest that tropical tree species in the region are at risk of extinction because of the intensification of warming, caused by emissions of greenhouse gases from human activities. Can’t escape. “The effects of climate change are everywhere – you can’t escape it,” says Kenneth J. Feeley, a researcher in the Department of Biological Sciences and International Centre for Tropical Botany at Florida International University. “Some people hold the notion that the Amazon is an isolated and pristine ecosystem, immune to disturbances. We need to change our mindset and open our eyes to the fact that, even in the middle of the Amazon or the remote Andes mountains, species are at risk. Read More here
Category Archives: The Science
11 August 2015, The Conversation, Odds keep rising for a big El Niño in 2015. El Niño has arrived, it’s getting stronger, and it’s not about to go away soon. And already there are rumblings that this could be a big one. El Niño in Australia means warmer temperatures, and sometimes, but not always, drier conditions. In 2014, some climatologists thought a big El Niño might have been on the cards. Ultimately, after some vigorous early warming in the Pacific, conditions only touched on El Niño thresholds. This year, with an event already established, climatologists are suggesting the odds are rising of an El Niño rivalling the record events of 1982 and 1997. So what’s all the fuss about, and how are conditions different from last year? Read More here
3 August 2015, Potsdam Institute, CO2 removal cannot save the oceans – if we pursue business as usual. Greenhouse-gas emissions from human activities do not only cause rapid warming of the seas, but also ocean acidification at an unprecedented rate. Artificial carbon dioxide removal (CDR) from the atmosphere has been proposed to reduce both risks to marine life. A new study based on computer calculations now shows that this strategy would not work if applied too late. CDR cannot compensate for soaring business-as-usual emissions throughout the century and beyond, even if the atmospheric carbon dioxide (CO2) concentration would be restored to pre-industrial levels at some point in the future. This is due to the tremendous inertia of the ocean system. Thus, CDR cannot substitute timely emissions reductions, yet may play a role as a supporting actor in the climate drama. Ocean acidification affects the shells of plankton like Pteropods. “Geoengineering measures are currently being debated as a kind of last resort to avoid dangerous climate change – either in the case that policymakers find no agreement to cut CO2 emissions, or to delay the transformation of our energy systems,” says lead-author Sabine Mathesius from GEOMAR Helmholtz Centre for Ocean Research Kiel and the Potsdam Institute for Climate Impact Research (PIK). “However, looking at the oceans we see that this approach carries great risks.” In scenarios of timely emissions reductions, artificially removing CO2can complement efforts. “Yet in a business-as-usual scenario of unabated emissions, even if the CO2 in the atmosphere would later on be reduced to the preindustrial concentration, the acidity in the oceans could still be more than four times higher than the preindustrial level,” says Mathesius. “It would take many centuries to get back into balance with the atmosphere.” Read More here
3 August 2015, Science Daily, Glaciers melting faster than ever. The World Glacier Monitoring Service has compiled worldwide data on glacier changes for more than 120 years. Together with its National Correspondents in more than 30 countries, the international service just published a new comprehensive analysis of global glacier changes. In this study, observations of the first decade of the 21st century (2001-2010) were compared to all available earlier data from in-situ, air-borne, and satellite-borne observations as well as to reconstructions from pictorial and written sources. “The observed glaciers currently lose between half a metre and one metre of its ice thickness every year — this is two to three times more than the corresponding average of the 20th century,” explains Michael Zemp, Director of the World Glacier Monitoring Service and lead author of the study. “Exact measurements of this ice loss are reported from a few hundred glaciers only. However, these results are qualitatively confirmed from field and satellite-based observations for tens of thousands of glaciers around the world.” Global glacier decline According to the international author team, the current rate of glacier melt is without precedence at global scale, at least for the time period observed and probably also for recorded history, as indicated also in reconstructions from written and illustrated documents. In addition, the study shows that the long-term retreat of glacier tongues is a global phenomenon. Read More here