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Blackouts and baseload: Debunking myths of AEMO reports and Liddell
Miner supplying Mt Piper power station seeks urgent hearing over invalid licence
Centennial Coal, whose licence was ruled invalid after its Springvale mine was found to be polluting Sydney’s water, wants matter resolved in two weeks
The miner that supplies Energy Australia’s Mount Piper coal power station with coal has sought an urgently expedited court hearing to establish how it can continue to operate without a valid licence.
But Centennial Coal did so without making a formal application for an early hearing and without evidence supporting the need for it, leaving the judge appearing sceptical of the claim.
Continue reading...Why did Hurricane Irma leave so many in the dark?
Cassini: Saturn probe heads towards destruction
How can we overcome Australia’s renewable energy policy deadlock?
UK power firm plans world’s largest battery storage project
July 2017 Australian Petroleum Statistics now available
Cassini: Saturn 'death dive' spacecraft in numbers
EU report on weedkiller safety copied text from Monsanto study
Exclusive: EU’s food safety watchdog recommended that glyphosate was safe but pages of report were identical to application from pesticide maker
The European food safety authority (Efsa) based a recommendation that a chemical linked to cancer was safe for public use on an EU report that copied and pasted analyses from a Monsanto study, the Guardian can reveal.
Glyphosate is the core ingredient in Monsanto’s $4.75bn (£3.5bn) a year RoundUp weedkiller brand and a battle over its relicensing has split EU countries, with a final decision on its authorisation expected in early November.
Continue reading...Australia's Brigalow forests almost gone
After 30 years of the Montreal Protocol, the ozone layer is gradually healing
This weekend marks the 30th birthday of the Montreal Protocol, often dubbed the world’s most successful environmental agreement. The treaty, signed on September 16, 1987, is slowly but surely reversing the damage caused to the ozone layer by industrial gases such as chlorofluorocarbons (CFCs).
Each year, during the southern spring, a hole appears in the ozone layer above Antarctica. This is due to the extremely cold temperatures in the winter stratosphere (above 10km altitude) that allow byproducts of CFCs and related gases to be converted into forms that destroy ozone when the sunlight returns in spring.
As ozone-destroying gases are phased out, the annual ozone hole is generally getting smaller – a rare success story for international environmentalism.
Back in 2012, our Saving the Ozone series marked the Montreal Protocol’s silver jubilee and reflected on its success. But how has the ozone hole fared in the five years since?
Read more: What is the Antarctic ozone hole and how is it made?.
The Antarctic ozone hole has continued to appear each spring, as it has since the late 1970s. This is expected, as levels of the ozone-destroying halocarbon gases controlled by the Montreal Protocol are still relatively high. The figure below shows that concentrations of these human-made substances over Antarctica have fallen by 14% since their peak in about 2000.
Past and predicted levels of controlled gases in the Antarctic atmosphere, quoted as equivalent effective stratospheric chlorine (EESC) levels, a measure of their contribution to stratospheric ozone depletion. Paul Krummel/CSIRO, Author providedIt typically takes a few decades for these gases to cycle between the lower atmosphere and the stratosphere, and then ultimately to disappear. The most recent official assessment, released in 2014, predicted that it will take 30-40 years for the Antarctic ozone hole to shrink to the size it was in 1980.
Signs of recoveryMonitoring the ozone hole’s gradual recovery is made more complicated by variations in atmospheric temperatures and winds, and the amount of microscopic particles called aerosols in the stratosphere. In any given year these can make the ozone hole bigger or smaller than we might expect purely on the basis of halocarbon concentrations.
Launching an ozone-measuring balloon from Australia’s Davis Research Station in Antarctica. Barry Becker/BOM/AAD, Author providedThe 2014 assessment indicated that the size of the ozone hole varied more during the 2000s than during the 1990s. While this might suggest it has become harder to detect the healing effects of the Montreal Protocol, we can nevertheless tease out recent ozone trends with the help of sophisticated atmospheric chemistry models.
Reassuringly, a recent study showed that the size of the ozone hole each September has shrunk overall since the turn of the century, and that more than half of this shrinking trend is consistent with reductions in ozone-depleting substances. However, another study warns that careful analysis is needed to account for a variety of natural factors that could confound our detection of ozone recovery.
The 2015 volcanoOne such factor is the presence of ozone-destroying volcanic dust in the stratosphere. Chile’s Calbuco volcano seems to have played a role in enhancing the size of the ozone hole in 2015.
At its maximum size, the 2015 hole was the fourth-largest ever observed. It was in the top 15% in terms of the total amount of ozone destroyed. Only 2006, 1998, 2001 and 1999 had more ozone destruction, whereas other recent years (2013, 2014 and 2016) ranked near the middle of the observed range.
Average ozone concentrations over the southern hemisphere during October 1-15, 2015, when the Antarctic ozone hole for that year was near its maximum extent. The red line shows the boundary of the ozone hole. Paul Krummel/CSIRO/EOS, Author providedAnother notable feature of the 2015 ozone hole was that it was at its biggest observed extent for much of the period from mid-October to mid-December. This coincided with a period during which the jet of westerly winds in the Antarctic stratosphere was particularly unaffected by the warmer, more ozone-rich air at lower latitudes. In a typical year, the influx of air from lower latitudes helps to limit the size of the ozone hole in spring and early summer.
The 2017 holeAs noted above, the ozone holes of 2013, 2014 and 2016 were relatively unremarkable compared with that of 2015, being close to the long-term average for overall ozone loss.
In general respects, these ozone holes were similar to those seen in the late 1980s and early 1990s, before the peak of ozone depletion. This is consistent with a gradual recovery of the ozone layer as levels of ozone-depleting substances gradually decline.
This year’s hole began to form in early August, and the timing was similar to the long-term average. Stratospheric temperatures during the Antarctic winter were slightly cooler than in 2016, which would favour enhancement of the chemical changes that lead to ozone destruction in spring. However, temperatures climbed above average in mid-August during a disturbance to the polar winds, delaying the hole’s expansion. As of the second week of September, the warmer-than-average temperatures have continued but the ozone hole has grown slightly larger than the long-term average since 1979.
Read more: Saving the ozone layer: why the Montreal Protocol worked.
While annual monitoring continues, which includes measurements under the Australian Antarctic Program, a more comprehensive assessment of the ozone layer’s prospects is set to arrive late next year. Scientists across the globe, coordinated by the UN Environment Program and the World Meteorological Organisation, are busy preparing the next report required under the Montreal Protocol, called the Scientific Assessment of Ozone Depletion: 2018.
This peer-reviewed report will examine the recent state of the ozone layer and the atmospheric concentration of ozone-depleting chemicals, how the ozone layer is projected to change, and links between ozone change and climate.
In the meantime we’ll watch the 2017 hole as it peaks then shrinks over the remainder of the year, as well as the ozone holes of future years, which will tend to grow less and less large as the ozone layer heals.
Andrew Klekociuk is employed by the Australian Antarctic Division and is funded by the Department of the Environment and Energy of the Australian government.
Paul Krummel is employed by CSIRO and receives funding from MIT, NASA, Australian Bureau of Meteorology, Department of the Environment and Energy, and Refrigerant Reclaim Australia.
US people of color still more likely to be exposed to pollution than white people
New federal government-funded study finds exposure to a key air pollutant is significantly influenced by race, far more than by income, age or education
People of color are still far more likely to suffer from harmful air pollution than white people across the US and this disparity has barely improved in recent years, despite overall improvements in air quality, a new federal government-funded study has found.
Related: London’s black communities disproportionately exposed to air pollution – study
Continue reading...The role of renewables in the UK energy mix | Letters
Your excellent editorial on the reducing cost of offshore wind power (13 September) is timely in identifying the increasingly futile case for new nuclear build. It does, however, repeat the fallacy that nuclear power “is a zero-carbon technology”. The carbon emissions involved in building such immense structures, in mining and transporting uranium, and in the transport, reprocessing and storage of waste, contribute to a considerable carbon burden. Estimates vary considerably, but studies suggest that the emissions from nuclear generation could be one-10th of those of fossil fuels, but twice those of wind power.
Furthermore, the need for a continuous supply is of only limited use when consumption patterns become distorted by, for example, the increased need to charge electric vehicles overnight, as your leader identifies. What is needed now, alongside continued investment in the latest generation of renewable production, is increased investment into a wide range of storage technologies, and further research and investment into the production of renewable heat.
Continue reading...Why scientists are so excited about Saturn's icy moon Enceladus
MPs to reopen inquiry into plastic bottle use
New inquiry will look into the viability of deposit schemes and taxes as ways to reduce impact of plastic waste on the environment
MPs are to mount a new inquiry into plastic bottles amid growing calls for a deposit scheme to reduce the impact of plastic waste in the ocean.
The investigation will also examine whether charges or taxes should be put on single-use plastic bottles and takeaway coffee cups to reduce their contribution to litter.
Continue reading...Strange eel: mystery of the Texas eyeless sea beast solved
Scary-looking fish found on a Texas beach after Hurricane Harvey is identified as a fangtooth snake-eel with the help of social media
The mystery of an eyeless fanged sea monster washed ashore by Hurricane Harvey has been solved by social media.
Preeti Desai, a science communicator, found the sinister-looking fish on a beach in Texas City after the storm, and asked Twitter users to help identify it.
Continue reading...Snow leopard off endangered list
How Cassini probe reached Saturn
Once-common ash trees and antelope added to red list of endangered species – in pictures
North American ash trees, that face extinction due to an invasive beetle, and African antelope join the latest IUCN list that includes 25,000 species at risk of extinction
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