This year’s Geminid meteor shower will be a true spectacle

Jonti Horner, University of Southern Queensland and Tanya Hill, Museum Victoria

The annual Geminid meteor shower is one of the highlights of every year and 2015 promises to be extra special, particularly for those in Australia.

The reason? The moon, which often interferes with our view of meteor showers by washing out all but the brightest members, will be just three days from new at the peak of the Geminids this month. As such, the best rates will be visible in dark, moonless skies.

What’s more, the timing of the event is perfect for Australia. The forecast maximum is expected to occur during the early hours of Tuesday, December 15, when the Geminid radiant (the point in the sky from which meteors appear to radiate) is riding high in the Australian sky.

The Geminids were first observed just one hundred and fifty years ago, relatively recently in astronomical terms. At first, just a few meteors were seen, but over the years the maximum rate observed has climbed.

For the past couple of decades, the annual peak has regularly reached (or exceeded) 120 meteors per hour. These high rates, the general brightness of the meteors, and the reliability of the Geminids combine to make it one of the best showers of the year.

The origins

Meteor showers occur when the Earth, on its orbit around the sun, passes through a swathe of debris left behind by one of the solar system’s small bodies. In most cases, the parent object is a comet, but in the case of the Geminids, the parent is actually a disintegrating asteroid named 3200 Phaethon.

Phaethon is a small, rocky object that has a remarkably eccentric orbit, which brings it closer to the sun than any other named asteroid.

At perihelion, it is just 20 million kilometres from the sun (well inside the orbit of Mercury) and its surface bakes in the daytime and freezes at night. With a rotation period of less than four hours, the constantly alternating extremes of temperature takes its toll on the asteroid’s surface.

The continual expansion and contraction causes Phaethon’s rocky surface to fracture and break. As these fragments are shed, they tend to spread around the asteroid’s orbit. It is this debris stream that Earth is passing through right now, to create the annual Geminid meteor shower.

Heading for peak activity

Unlike the Perseids and Quadrantids, two of the year’s other finest showers, the Geminids are easily observed from both the northern and southern hemispheres. This makes them a true annual treat, wherever you are on the planet.

The Geminids radiant travels across the northern sky, as seen from Perth.

The Geminids are already underway, and will slowly build towards their peak on Tuesday, December 15. Those peak rates usually last around a day or so, but are then followed by a rapid decay in the number of meteors seen. The shower ceases to be active just three days after maximum.

The time of the peak is expected to occur around 4am AEST (Qld), 5am AEDT (NSW, ACT, Vic and Tas), 4:30am ACDT (SA), 3:30am ACST (NT) and 2am AWST (WA).

How to see the Geminids

Although the Geminids can be observed from anywhere in Australia, the further north you live, the higher the radiant will appear in the sky and the better your view will be.

The radiant of the shower rises in the late evening (see the table, below). It’s not possible to see meteors before then, but once the radiant rises the show will improve, hour on hour as the radiant gets ever higher in the sky.

For the first couple of hours after the radiant rises, even on the night of maximum, meteors will likely be infrequent, but these Earth-grazers can be truly spectacular. Entering Earth’s atmosphere at the shallowest of shallow angles, they can blaze a trail across almost the entire night sky.

As the night passes, and the radiant rises ever higher, rates should increase. The best way to see the greatest number of meteors is to first find the radiant in the sky.

The Geminids as seen from Brisbane. The further north you are, the higher the radiant appears in the sky.
Stellarium/Tanya Hill, CC BY

The Geminids appear to come from close to the bright star Castor, one of the two brightest stars in Gemini (hence the name “Geminids”).

Gemini can found below the constellation of Orion, as seen from the southern hemisphere. It rises in the north-east in the late evening, then passes through north to the north-west as the night progresses.

The Geminids as seen from Hobart.
Stellarium/Tanya Hill, CC BY

Once you’ve found the radiant, turn your gaze around 30 to 45 degrees away, either to the left or the right (look towards the direction with the least light pollution for the best results). Then look about 30 to 45 degrees above the horizon.

Looking this distance from the radiant is an ideal compromise. It means that you will be looking through a large enough volume of atmosphere to see a reasonable number of meteors, without looking so far from the radiant that any meteors have already burned up before reaching your field of view.

Also, remember when looking for meteors to make sure you give your eyes time to adapt to the darkness. It can take more than half an hour before your eyes have fully dilated, and you become able to see the faintest stars and many more meteors.

Any bright light (the headlights of a passing car or someone checking their smartphone to read an e-mail) resets the clock.

Also, be careful of your safety, and be aware of any Earth-born hazards when viewing the night sky. One of us (Jonti) had a real shock as a teenager, when observing the Perseid meteor shower from an isolated golf course. At about 10pm he heard a “whoosh”, and was almost drenched by a previously unseen sprinkler!

So good luck, set your alarm clock, and hope for clear skies for this year’s Geminids!

The Conversation

Jonti Horner, Vice Chancellor’s Senior Research Fellow, University of Southern Queensland and Tanya Hill, Honorary Fellow of the University of Melbourne and Senior Curator (Astronomy), Museum Victoria

This article was originally published on The Conversation. Read the original article.


Beyond Paris: what was really achieved at the COP21 climate summit, and what next?

Michael Hopkin, The Conversation

As French foreign minister Laurent Fabius brought his gavel down on the most ambitious climate deal ever struck, at 7:27pm on Saturday December 12, 2015, applause broke out throughout the sprawling conference centre in Le Bourget.

It spread even into the cavernous media centre that played host to an estimated 3,700 journalists. It was celebration mixed with relief – a punishing two weeks of negotiations were finally over, albeit 24 hours later than planned.

The result is the first agreement requiring all nations, rich and poor, to pledge action on climate change, with the stated aim of restricting global warming to “well below 2℃ above pre-industrial levels”, and to strive to limit it to 1.5℃.

Time to terminate greenhouse emissions? Hollywood star and former Californian Governor Arnold Schwarzenegger says it’s time to act.
Michael Hopkin/The Conversation, CC BY-SA

Alongside the politicians, negotiators, business leaders and celebrities at the Paris talks were dozens of The Conversation’s authors from around the world, as well as two Conversation editors. Before, during and after the conference, we have published more than 200 analysis articles, many commissioned from inside the summit.

We featured contributions from at least 140 academics at 74 universities. Those articles garnered nearly 1 million reads and were republished in media outlets worldwide, including Quartz, Newsweek, IFLScience,, RawStory, Mamamia, Economy Watch, SBS, The Brisbane Times,, SciBlogs NZ and Business Spectator.

But as many of our authors have pointed out, the real test of whether Paris was a success will be seen in what happens next. So we’ve pulled together two dozen of the best articles on the big scientific, political and economic challenges beyond Paris.

As you’ll see, these highlights show the value of The Conversation’s global newsroom in bringing you insights from experts worldwide, working with all of our teams in France, the UK, US, Africa and Australia.

In case you want to catch up on your reading offline, we’ve also created a special report for you to download.

The big picture

For a fast overview, start with our infographic to see what was agreed at a glance.

A snapshot of our infographic, showing the big gap between pledged emissions cuts and achieving a 2℃ target.

Then read why Boston University’s Henrik Selin and Adil Najam argue the agreement was good, bad and ugly.

Clive Hamilton from Charles Sturt University describes the emotional turmoil as the deal was being struck.

And Jackson Ewing from Singapore’s Nanyang Technological University explains why China and the United States have finally found common purpose on climate change.

The scientific challenge ahead

Paris summit attendees in silhouette in front of a screen showing a global climate anomalies.
Reuters/Stephane Mahe

CSIRO’s Pep Canadell and Stanford University’s Rob Jackson explain why the Paris Agreement was an extraordinary achievement, but that our real work to cut emissions starts now.

That’s because, as Katja Frieler from Germany’s Potsdam Institute for Climate Impact Research shows, global warming is already affecting us (2015 is about to set a new global temperature record) and we’re still heading towards a 2.7℃ world.

New research from the Global Carbon Project shows where in the world emissions are rising or falling, and how much we need to do to achieve a healthy global carbon budget.

Need a quick explainer on what greenhouse gases are? Université de Lille’s Céline Toubin can help. (And if you speak French, you can also read it in French, along with the rest of The Conversation France’s summit coverage.)

But emissions cuts are no longer enough; Oxford University’s Myles Allen argues we’ll also have to find ways to put carbon back in the ground. How? One answer is lying beneath our feet: carbon stored in soil is a bigger solution than you might realise, as a team from the University of Sydney explain.

Show me the money: economic trends to watch

The most surprising revelation of the Paris climate talks was, according to Clive Hamilton, “the astonishing shift” he saw among big business and investors over the past 12 months.

The University of Adelaide’s Peter Burdon was also struck by that shift, especially the way that a growing number of business leaders are now clamouring for a global carbon tax.

Talk is cheap, especially if it’s not backed up with serious funding.
Reuters/Stephane Mahe

But our experts had different views on the best way to price carbon. Katherine Lake from the University of Melbourne argues carbon markets – that is, trading permits to pollute – could play an essential role. However, Steffen Böhm from the University of Essex disagrees, warning that carbon markets have created more problems than they’ve solved so far.

Luke Kemp from the Australian National University looks at how the Paris Agreement left a big question unanswered: what about coal? And no matter what we do now, most people agree adaptation is crucial – yet as the University of Minnesota’s Jessica Hellmann explains, we’re still too hazy on what that will cost.

What could we do if we were really serious about climate change? University College London’s Chris Grainger makes the case to invest as if we were in a global ‘space race’.

Voices of the many, not just the few

Campaigners and those representing poorer nations kept the pressure on right to the end.
Reuters/Jacky Naegelen

Speaking with Matt McDonald from the University of Queensland, Saleemul Huq – who has attended all 21 UN climate summits – reflected on the “very significant change” in negotiating blocs at Paris, which saw vulnerable countries making themselves heard more loudly than before.

Ambuj D Sagar from the Indian Institute of Technology Delhi explains why developing countries need more than betting billions on clean energy breakthroughs. Maria Ivanova from the University of Massachusetts Boston highlights the work of 15 female climate champions around the world – but we still need far more.

Stellenbosch University’s Anthony Mills shows what Africa can learn from China about climate change.

COP21: one of the few places where your work is scrutinised by a giant animatronic polar bear.
Michael Hopkin/The Conversation, CC BY-SA

Many climate activists won’t be satisfied by the Paris deal, and will keep pushing for action on fossil fuel use, energy market reform and more, as the University of Sydney’s Rebecca Pearse explains.

And there’s a good reason why, according to the University of Lapland’s Ilona Mettiäinen: polar bears aren’t the only ones facing climate impacts in places like the Arctic – those impacts also affect people, locally and globally.

Thank you to all of our authors, editors and readers around the world for your interest in our Paris 2015 climate summit coverage.

As The Conversation continues to grow in 2016 and beyond, we hope to bring you even better, more comprehensive expert coverage of the biggest global issues we face – all of which will always be free to read, share and republish.

* Download your complete copy of our Beyond Paris special report.

The Conversation

Michael Hopkin, Environment + Energy Editor, The Conversation

This article was originally published on The Conversation. Read the original article.

After Paris: now what for Australia’s climate policy?

Tim Nelson, University of New England; Judith McNeill, University of New England; Mahinda Siriwardana, University of New England, and Sam Meng, University of New England

Under the Paris climate agreement, Australia has stated that it will reduce greenhouse gas emissions by 26-28% by 2030 compared to 2005 levels.

The Paris Agreement will aim to limit warming to 1.5C.
Tim Nelson, Author provided

To limit temperature increases to less than 2°C, concentrations of greenhouse gases in the atmosphere need to be limited to 450 parts per million or lower . This would require reductions in global emissions of between 40% and 70% by 2050 and complete decarbonisation of the world economy by 2100.

The Climate Institute has found that under the most “generous” emission reduction methods, Australia’s total carbon budget between now and 2050 would need to be 10 billion tonnes of greenhouse gases or lower.

This budget would be depleted by around 2033 if Australia continued to emit greenhouse gases at current levels.

If the budget was exhausted more gradually at a fixed reduction rate, Australia would need to reduce its emissions by 4% each year to 2050 – approximately 45% lower than today in 2030.

Current policy settings likely to require enhancements

Achieving these emission reductions will be challenging under current policy settings. Australia needs to consider how it will implement long-term emission reduction policies that allow for existing capital stock, such as fossil-fuel-fired power stations in the electricity sector, to transition to low/zero emissions.

Australia’s policy initiatives should also focus on the strategic importance of our resources – primarily coal, gas and uranium. Australia has 33%, 10% and 2% respectively of the world’s uranium, coal and gas resources and around 25% of Australia’s goods export revenues are sourced from the sale of mineral fuels. Given the importance of these exports for the economy, greater consideration of appropriate and cost-effective policy mechanisms for these resource industries would be sensible.

Much of the public policy discussion is focused on whether a carbon price (a carbon tax or emissions trading scheme) should be introduced. Alternatives may be worth considering, particularly in capital intensive industries such as electricity.

In the US, new performance standards establish separate greenhouse gas limits for coal and gas generators. Coal plants will be required to meet a 12-month rolling average of 0.5 tonnes per megawatt-hour. Gas-fired generation facilities will be required to meet a limit of between 0.45-0.5 tonnes per megawatt-hour depending on their technical characteristics.

In Canada regulations force the retirement of power stations that are greater than 50 years old, or must be retrofitted with carbon capture and storage (CCS) technology to achieve an emissions profile of around 0.4 tonnes per megawatt-hour – equivalent to an efficient gas turbine.

The role of natural gas

Both Australia and the US are experiencing “gas revolutions”, but the outcomes with regards to gas prices could not be more different.

In Australia, gas prices and availability are being impacted by unprecedented increases in east-coast demand associated with the development of an east-coast LNG export industry.

Even without rising gas prices, to replace coal-fired power plants with gas turbines would take a carbon price of around A$110 per tonne.

This carbon price is more than four times higher than the previous Australian fixed carbon price of A$23 per tonne and would result in electricity price uplifts of roughly A$90 per megawatt-hour – an increase of 30% on a residential bill . The A$23 carbon price caused household electricity bills to rise by around 10% during the two years of its operation.

Barriers to exit and an ageing power station fleet are another key consideration for policy makers. Around 75% of the existing thermal (coal and gas) generation plants have passed their original engineering life. More importantly, around 20% are more than 40 years old.

While carbon pricing is likely to be difficult to implement due to political opposition and the effects of potentially higher gas prices, regulatory and legislative instruments are in place which have the effect of reducing emissions.

The most prominent of these is the Large-Scale Renewable Energy Target (LRET). Globally, such a policy is well founded – with 144 countries having support mechanisms for renewables of some type.

Electricity sector decarbonisation could be achieved with a renewable energy target if it was coupled with a policy to close old coal-fired power stations. This would be an adaption of performance standards for new electricity generators (such as those proposed in the US) and a closure policy (as adopted in Canada).

The role of carbon, capture and storage

It may also be in Australia’s interests to expand the Renewable Energy Target to include projects using coal and gas with zero or negligible emissions.

As a major exporter of coal and gas, Australia’s export revenues could be significantly curtailed without carbon capture and storage (CCS) technologies. Importantly, CCS should not be given a free-ride but would be required to compete with renewable sources.

Australia could advocate for other nations to adopt such a policy through international negotiations. This may create a deeper, liquid market for CCS-style technologies which would provide potential opportunities for Australian energy exporters.

If the policy objective is to structurally decarbonise the Australian economy, international permit trading may not result in greenhouse gas reduction actually taking place within Australia.

It may also do nothing to address the risks to Australian energy exports in a world where significant efforts are being made to substitute coal and gas.

In contrast, expanding the quantity and eligibility of zero-emissions abatement under the renewable energy target, combined with a Canadian-style generator closure policy, could both decarbonise the Australian electricity sector and provide opportunities for Australian energy exporters to compete in a zero emissions future.

This article is based upon a forthcoming article in Economic Papers titled, ‘Australian climate change policy: where to from here?’

The Conversation

Tim Nelson, PhD candidate, University of New England; Judith McNeill, Senior Research Fellow, Institute for Rural Futures, BCSS, UNE, University of New England; Mahinda Siriwardana, Professor of Economics, School of Business Economics and Public Policy, University of New England, and Sam Meng, Researcher in economics, University of New England

This article was originally published on The Conversation. Read the original article.

After Paris, the future of Australian coal is downhill

Gary Ellem, University of Newcastle

The ink is barely dry on the Paris climate agreement and the debate has already started on how the deal will affect the future of fossil fuels, particularly coal.

Following the deal on Sunday, the mining industry has responded that Australian coal will remain an important provider of affordable energy to developing countries. The industry argues new low emissions technologies will keep coal in business as the world cuts carbon.

Foreign minister Julie Bishop echoed the sentiment in Paris last week, stating “coal-fired power generation is here to stay.”

The agreement aims to limit global temperature rise to less than 2℃, with an aspiration of 1.5℃. So what is the future of coal in a world that meets these temperature limits?

Who’s going to build the new coal infrastructure?

Keeping warming “well below 2℃ above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5℃” essentially means all new electricity generation from now on must be zero emissions or have a short amortisation life. Current emissions-intensive generation will also have to be phased out in line with the end of its initial design life.

Most coal in Australia is mined to be exported. For Australian coal exports to continue to play a significant role in our balance of trade, we must have international customers.

Australia produces both thermal coal for electricity and metallurgical coal for manufacturing, which is exported mainly to countries in Asia. Some of these customers, such as China and India, have their own coal production sectors, which produce significantly more coal than Australia. Others, such as Japan, are completely import dependent.

Whichever way the coal is used, it will add to the amount of greenhouse gases in the atmosphere unless these emission are captured by carbon capture and storage (CCS) technologies.

The infrastructure that will power our international customers’ electricity grids, steel and cement plants in 2050 largely hasn’t been built yet. In a less than 2℃ world, all of this infrastructure will have to be close to zero emissions. In a 1.5℃ world, any remaining emissions will have to be offset.

This means that if our customers decide to stay with coal, they will have to replace their existing infrastructure with new infrastructure incorporating carbon capture and storage, and even further offset emissions for a 1.5℃ future with the use of biomass.

It’s clear that China has already opted for an anything but coal policy. The policy future for India is not so clear, but they are clearly planning to be more self sufficient in coal production regardless of climate objectives. Neither of these look good for the future of Australian coal exports in either the short or long term.

The competition is heating up

The Australian coal export sector is threatened by both the rise of competing technologies and other suppliers.

Competing technologies in the electricity generation space are numerous and include nuclear as well as a swathe of renewable energy technologies that are becoming cheaper and more practical.

It’s clear that carbon capture and storage technologies have failed in the current competition environment as a cheap alternative to the other low and zero-emissions technologies such as renewables. Coal has rapidly ceded ground to gas, wind, hydro and solar in key markets such as the US and China.

The long-term outlook for coal for electricity then, is shaky at best. Australia is competing for market share in a shrinking market. The International Energy Agency report quoted by the Minerals Council for a rosy coal future is very clear that the modelling is based on the continuation of pre-Paris trends rather than the Paris agreement.

Even the well-trodden claims that intermittent renewables can’t supply the baseload power normally supplied by coal are looking flaky. Energy storage in the form of batteries in particular is rapidly getting cheaper and building in production capacity. A number of different battery types including lithium ion, sodium ion, aluminium ion and liquid metal batteries are all in development with on grid storage markets in mind.

The outlook for metallurgical coal may be more promising, simply because there are fewer technologies to compete.

Coal is used predominantly in blast furnaces to convert iron ore into metallic iron. Blast furnaces use coking coal to hold iron ore in place, while cheaper Pulverised Coal Injection (or PCI) coal is used to remove oxygen from the iron.

PCI coal can be replaced by charcoal from plants, reducing emissions by 18% to 40%. But there’s no current replacement for coking coal used in a blast furnace.

The Hismelt process from Rio Tinto can convert iron ore to new iron without the need for coking coal. But this technology is in its commercial infancy.

Should we rely on the Australian coal industry?

The coal industry has played an important role in the development of Australia as a modern industrialised economy. It has formed the basis for energy security in the Australian electricity sector and our domestic steel sector.

In more recent times, coal has been a major export commodity for Australia and has also powered the export-focused aluminium sector. Despite all of these great achievements, it’s hard to see a long-term positive future for the industry in a global marketplace looking for competitive solutions to their 2℃ and 1.5℃ needs.

Innovation is borne of constraint however, and it will be good for all of us if carbon capture and storage could be made cheap enough and deployable enough for widespread use. There are reasons for pursuing this technology besides coal. Carbon capture and storage can be combined with bioenergy in the form of BECCS to develop one of the few large-scale ways in which we may actively remove greenhouse gases from the atmosphere.

Given the likely demise of this substantial national export industry over the next few decades, we would be wise to think about what other innovative opportunities we can draw from the sector while it still has scale. Our coal miners are in the energy industry, but we would be foolish and simplistic if we think the only replacement industries emerging from coal is renewable energy.

We have a coal export industry simply because we have an area of natural advantage in coal i.e. high quality coal resources with rail and port access. We are yet to identify an equivalent area of natural advantage in renewables that could power a similarly scaled export industry. Yes we have sun and wind in abundance, but there is no real mechanism yet to export that to an international market.

But all is not lost. Mines are large consumers of energy and technology resources and have management responsibilities for significant tracts of the Australian landscape.

With the right guidance and incentives, the industry may yet lay the foundations for a sustainable legacy for our national economy and local communities in exportable products such as an innovative approach to professional services, transport technology and high intensity food production.

Gary will be on hand for an Author Q&A between 10 and 11am AEST on Wednesday, December 16, 2015. Post your questions in the comments section below.

The Conversation

Gary Ellem, Conjoint Academic in Sustainability, University of Newcastle

This article was originally published on The Conversation. Read the original article.