1 March 2017, Climate News Network, Spring moving forward at record rate. Spring is arriving ever earlier in the northern hemisphere. One sedge species in Greenland is now springing to growth 26 days earlier than it did a decade ago. And in the wintry United States, spring arrived 22 days early this year in Washington DC, the national capital.The evidence comes from those silent witnesses, the natural things that respond to climate signals. The relatively new science of phenology – the calendar record of first bud, first flower, first nesting behaviour and first migrant arrivals – has over the last three decades repeatedly confirmed meteorological fears of global warming as a consequence of the combustion of fossil fuels. Researchers say the evidence from the plant world is consistent with the instrumental record: 2016 was the hottest year ever recorded, and it was the third record-breaking year in succession. Sixteen of the hottest years ever recorded have happened in the 21st century. Arctic spring And the most dramatic changes are observed in the high Arctic, the fastest-warming place on the planet, according to a study in Biology Letters. As the polar sea ice retreats, the growing season gets ever longer – and arrives earlier. The pattern is not consistent: grey willow sticks to its original timetable, and dwarf birch growth has advanced about five days earlier for each decade. But the sedge, almost four weeks ahead of its timetable in a decade, holds the record, according to a study that observed one plot at a field site in West Greenland, 150 miles inland, for 12 years. Read More here
Tag Archives: forest response
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
9 September 2016, The Conversation, EcoCheck: the Grampians are struggling with drought and deluge. Our EcoCheck series takes the pulse of some of Australia’s most important ecosystems to find out if they’re in good health or on the wane. The Grampians National Park is a large conservation reserve, sprawling across 168,000 hectares embedded in western Victoria’s agricultural landscape. With a rich cultural heritage and regionally important flora and fauna, it is a hugely significant area for conservation. But in recent years it has been subjected to a series of major wildfire events, a flood, and long periods of low rainfall. Our research shows that this has sent small mammal populations on the kind of boom-and-bust rollercoaster ride usually seen in arid places, not temperate forests.The fire and the flood We began studying the Grampians in 2008, investigating how small mammals had responded to a catastrophic wildfire that burned half of the national park in 2006. What started as a one-year study has turned into a long-term research program to investigate how the past few years of hypervariable rainfall and heightened bushfire activity have affected the animals that live in the park. Fortunately (for our study, at least), the beginning of our research in 2008 was in the middle of a long run of very poor rainfall years, as the Millennium Drought reached its height. The drought was broken at the end of 2010 by the Big Wet, which led to well-above-average rainfall and floods in the Grampians. But soon after, rainfall rapidly dipped back to below average. It has stayed there ever since. We also saw two more major fire events, in 2013 and 2014, which together with the 2006 fire burned some 90% of the Grampians landscape. Read More here
5 September 2016, DESMOG, Climate Impacts: Melting Glaciers, Shifting Biomes and Dying Trees in US National Parks. Trees are dying across Yosemite and Yellowstone national parks. Glaciers are melting in Glacier Bay National Park and Preserve in Alaska. Corals are bleaching in Virgin Islands National Park. Published field research conducted in U.S. national parks has detected these changes and shown that human climate change – carbon pollution from our power plants, cars and other human activities – is the cause. As principal climate change scientist of the U.S. National Park Service, I conduct research on how climate change has already altered the national parks and could further change them in the future. I also analyze how ecosystems in the national parks can naturally reduce climate change by storing carbon. I then help national park staff to use the scientific results to adjust management actions for potential future conditions. Research in U.S. national parks contributes in important ways to global scientific understanding of climate change. National parks are unique places where it is easier to tell if human climate change is the main cause of changes that we observe in the field, because many parks have been protected from urbanization, timber harvesting, grazing and other non climate factors. The results of this research highlight how urgently we need to reduce carbon pollution to protect the future of the national parks. Melting Glaciers, Dying Trees Human-caused climate change has altered landscapes, water, plants and animals in our national parks. Research in the parks has used two scientific procedures to show that this is occurring: detection and attribution. Detection is the finding of statistically significant changes over time. Attribution is the analysis of the different causes of the changes. Around the world and in U.S. national parks, snow and ice are melting. Glaciers in numerous national parks have contributed to the global database of 168 000 glaciers that the Intergovernmental Panel on Climate Change (IPCC) has used to show that human climate change is melting glaciers. Field measurements and repeat photography show that Muir Glacier in Glacier Bay National Park and Preserve in Alaska lost 640 meters to melting from 1948 to 2000. Read More here