This is a summary of the stories we published in the week ending Saturday 11 May.
9 May – …The Makuxi, one of Brazil’s largest indigenous communities, with about 19,000 people and 140 villages, inhabit an area of savannah and sierras in the far northern state of Roraima, sharing borders with Venezuela and Guyana. The Brazilian Government has a programme to bring electricity to rural communities which is called Light For All, and it is considering building a number of dams inside the Makuxi reserve. But the Makuxi have come up with another idea. The Brazilian Atlas of Wind Potential shows that the northern region of their reserve, Raposa-Serra do Sol, enjoys some of the strongest winds in the country, with speeds of up to 11 metres per second being registered, and an average of six to nine metres. So in February three towers were installed to measure the winds over the period of a year, in order to calculate the potential for generating energy… They hope the energy to be generated will be enough, not only for domestic consumption, but also for the agricultural activities they are also preparing, as part of their plan to develop their reserve sustainably.
12 May – Without serious action to limit global warming, more than half of all land plants and a third of all animals could find their living space dramatically reduced later this century. That is, if global average temperatures rise by 4°C the climatic regions in which these creatures thrive will shift towards the poles, habitats will dwindle, ecosystems will alter, and ever greater numbers of species will struggle to survive in ever more constrained conditions. That’s the bad news. The somewhat less bad news is that stringent and dramatic reductions in greenhouse gas emissions could buy time: about another four decades in which humanity’s fellow species could adapt to new circumstances. Rachel Warren of the University of East Anglia and colleagues in the UK, Australia and Colombia report in Nature Climate Change that they used a 21st century creation, the Global Biodiversity Information Facility (GBIF)… to examine the known ranges and habitats of more than 48,000 species of plant and animal and tried to calculate how these would be affected by “business as usual” scenarios for greenhouse gas emissions.
13 May – Scientists tread very carefully when it comes to glaciers. While the consensus is that glaciers around the world are generally in retreat, there are the exceptions… A new study published in the journal Nature questions whether present trends of ice loss on the Greenland ice sheet will be maintained. The report – Future Sea-level Rise from Greenland’s Major Outlet Glaciers in a Warming Climate – looks at the behaviour of the four major fast flowing glaciers in Greenland. The Petermann, Kangerdlugssuaq, Helheim and Jakobshavn glaciers together drain about 22% of the island’s ice sheet. By building up a computer model of these four glaciers, scientists have revealed that the shape of the ground beneath the ice has a marked impact on the way the ice moves, with the rate at which the glaciers are losing ice depending critically on the shape of the fjords in which they sit and the topography of the rock below them. In turn, this has led the scientists to doubt whether present rates of ice loss and the “calving” of icebergs from the glaciers will be maintained.
14 May – Most birds are acutely sensitive to changes in temperature. Scientists now say that changes in climate and warmer temperatures in parts of Europe have resulted in the migration patterns of certain birds being radically altered. A study looking at the migration patterns of three species of duck – the goldeneye, goosander and tufted duck – has found there has been a sharp decrease in the number of birds migrating south. The study, published in Global Change Biology, examined the migration patterns of the three duck species over the 1980 to 2010 period. It found that mid-winter numbers of individual ducks at the southern edge of the species’ normal distribution range – in France, Ireland and Switzerland – had dropped by nearly 120,000. Meanwhile mid-winter numbers of the species in Finland and Sweden – in areas where the ducks breed in summer – had increased by a similar amount.
15 May – Around 20% of the snow cover in North America’s greatest mountain range has been lost – because of warmer springs in the last three decades. Scientists from the American Geophysical Union and the US Geological Survey report that they had established a pattern of snowfall in the northern and southern Rockies: when the snowpack was large in the northern Rockies, it might be correspondingly meagre in the southern mountains and vice versa. But since the 1980s, snowpack declines have occurred simultaneously along the entire length of the Rocky Mountains, with unusually severe declines in the north… Meanwhile, at the American Geophysical Union’s meeting in Cancun, Mexico, researchers report that the world’s highest peak, Mt Everest, is beginning to lose its snow and ice. They report, after studies of satellite imagery of the mountain and the Sagarmatha National Park, that the Everest region in the Himalayas has been warming, and snow precipitation declining, for the last 20 years. Everest glaciers have shrunk by 13% in the last 50 years and the snowline has moved 180 metres uphill.
16 May – A new analysis of scientists’ articles on global warming and climate change has found almost unanimous agreement that humans are the main cause. The comprehensive examination of peer-reviewed articles on the topic showed an overwhelming consensus among scientists that much recent warming is anthropogenic – the result of human activities. The study, the most comprehensive so far, identified 4,000 article summaries, or abstracts, from papers published in the past 21 years which stated a position on the cause of recent global warming. Its finding that 97% of them echoed the consensus view – that anthropogenic global warming (AGW) is responsible for the rise in global average temperatures – is remarkably similar to the conclusion of a smaller study completed in 2004. The latest study, Quantifying the consensus on anthropogenic global warming in the scientific literature, which was led by John Cook of the University of Queensland, Australia, is published in IOP Publishing’s journal Environmental Research Letters.
17 May – Extra cloud cover caused by emissions of industrial pollutants is known to reduce the effects of global warming, but its impact in reducing temperatures has been over-estimated in the climate models, new research has found. This is particularly significant for China and India, because it has been believed that these two giant countries would be partly shielded from the effects of climate change by their appalling industrial pollution. The Max Planck Institute for Chemistry in Germany believes this potential cooling effect has been exaggerated… Current climate models assume that hydrogen peroxide and ozone have a large role in creating the sulphates [responsible], but the new research shows that the catalysts for the chemical reaction are more likely to be metal ions like iron, manganese, titanium or chromium. The key factor is that all of these are heavier than hydrogen peroxide and ozone, and because of this are more likely to fall out of the cloud through the pull of gravity, thus considerably reducing the cooling effect of the original pollution.
18 May – An ice-free Arctic, the disappearance of tundra and forests up to the edge of the newly open ocean is how the north will look as the natural world reacts to the new climate caused by carbon dioxide reaching 400 parts per million (ppm) in the atmosphere, according to analysis of new lake sediments. So far scientists have been guessing what a warmer world will look like, but lake bed cores from Russia provide evidence of the trees and plants that thrived north of the Arctic Circle last time CO2 was at 400 ppm – a barrier broken earlier this month. There is a time lag of up to 30 years for the temperature to be forced up by the extra CO2 in the atmosphere, so the scientists’ findings give a clue to what to expect by the middle of the century. Julie Brigham-Grette of the University of Massachusetts Amherst, who led a team of international scientists, says summer temperatures were about 8°C warmer in the Arctic than they are today, and the rainfall three times greater. At the same time the West Antarctic ice sheet did not exist, showing that both landscape and sea level were vastly different.