Wind farms are hardly the bird slayers they’re made out to be. Here’s why


File 20170616 512 12qly6u
The potential to harm local birdlife is often used to oppose wind farm development. But research into how birds die shows wind farms should be the least of our concerns.
from www.shutterstock.com

Simon Chapman, University of Sydney

People who oppose wind farms often claim wind turbine blades kill large numbers of birds, often referring to them as “bird choppers”. And claims of dangers to iconic or rare birds, especially raptors, have attracted a lot of attention.

Wind turbine blades do indeed kill birds and bats, but their contribution to total bird deaths is extremely low, as these three studies show.

A 2009 study using US and European data on bird deaths estimated the number of birds killed per unit of power generated by wind, fossil fuel and nuclear power systems.

It concluded:

wind farms and nuclear power stations are responsible each for between 0.3 and 0.4 fatalities per gigawatt-hour (GWh) of electricity while fossil-fuelled power stations are responsible for about 5.2 fatalities per GWh.

That’s nearly 15 times more. From this, the author estimated:

wind farms killed approximately seven thousand birds in the United States in 2006 but nuclear plants killed about 327,000 and fossil-fuelled power plants 14.5 million.

In other words, for every one bird killed by a wind turbine, nuclear and fossil fuel powered plants killed 2,118 birds.

A Spanish study involved daily inspections of the ground around 20 wind farms with 252 turbines from 2005 to 2008. It found 596 dead birds.

The turbines in the sample had been working for different times during the study period (between 11 and 34 months), with the average annual number of fatalities per turbine being just 1.33. The authors noted this was one of the highest collision rates reported in the world research literature.

Raptor collisions accounted for 36% of total bird deaths (214 deaths), most of which were griffon vultures (138 birds, 23% of total mortality). The study area was in the southernmost area of Spain near Gibraltar, which is a migratory zone for birds from Morocco into Spain.

Perhaps the most comprehensive report was published in the journal Avian Conservation and Ecology in 2013 by scientists from Canada’s Environment Canada, Wildlife Research Division.

Their report looked at causes of human-related bird deaths for all of Canada, drawing together data from many diverse sources.

The table below shows selected causes of bird death out of an annual total of 186,429,553 estimated deaths caused by human activity.

https://datawrapper.dwcdn.net/Zg2hk/1/

Mark Duchamp, the president of Save the Eagles International is probably the most prominent person to speak out about bird deaths at wind farms. He says:

The average per turbine comes down to 333 to 1,000 deaths annually which is a far cry from the 2-4 birds claimed by the American wind industry or the 400,000 birds a year estimated by the American Bird Conservancy for the whole of the United States, which has about twice as many turbines as Spain.

Such claims from wind farm critics generally allude to massive national conspiracies to cover up the true size of the deaths.

And in Australia?

In Australia in 2006 a proposal for a 52-turbine wind farm plan on Victoria’s south-east coast at Bald Hills (now completed) was overruled by the then federal environment minister Ian Campbell.

He cited concerns about the future of the endangered orange-bellied parrot (Neophema chrysogaster), a migratory bird said to be at risk of extinction within 50 years. The Tarwin Valley Coastal Guardians, an anti wind farm group that had been opposing the proposed development.

Interest groups have regularly cited this endangered bird when trying to halt a range of developments.

These include a chemical storage facility and a boating marina. The proposed Westernport marina in Victoria happened to also be near an important wetland. But a professor in biodiversity and sustainability wrote:

the parrot copped the blame, even though it had not been seen there for 25 years.

Victoria’s planning minister at the time, Rob Hulls, described the Bald Hills decision as blatantly political, arguing the federal conservative government had been lobbied by fossil fuel interests to curtail renewable energy developments. Hulls said there had been:

some historical sightings, and also some potential foraging sites between 10 and 35 kilometres from the Bald Hills wind farm site that may or may not have been used by the orange-bellied parrot.

Perhaps the final word on this topic should go to the British Royal Society for the Protection of Birds. It built a wind turbine at its Bedfordshire headquarters to reduce its carbon emissions (and in doing so, aims to minimise species loss due to climate change). It recognised that wind power is far more beneficial to birds than it is harmful.


The ConversationSimon Chapman and Fiona Crichton’s book, Wind Turbine Syndrome: a communicated disease, will be published by Sydney University Press later this year.

Simon Chapman, Emeritus Professor in Public Health, University of Sydney

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

Volcanoes under the ice: melting Antarctic ice could fight climate change



File 20170615 24988 wlh6r4
Furious winds keep the McMurdo Dry Valleys in Anarctica free of snow and ice. Calcites found in the valleys have revealed the secrets of ancient subglacial volcanoes.
Stuart Rankin/Flickr, CC BY-NC

Silvia Frisia, University of Newcastle

Iron is not commonly famous for its role as a micronutrient for tiny organisms dwelling in the cold waters of polar oceans. But iron feeds plankton, which in turn hold carbon dioxide in their bodies. When they die, the creatures sink to the bottom of the sea, safely storing that carbon.

How exactly the iron gets to the Southern Ocean is hotly debated, but we do know that during the last ice age huge amounts of carbon were stored at the bottom of the Southern Ocean. Understanding how carbon comes to be stored in the depth of the oceans could help abate CO2 in the atmosphere, and Antarctica has a powerful role.

Icebergs and atmospheric dust are believed to have been the major sources of this micronutrient in the past. However, in research published in Nature Communications, my colleagues and I examined calcite crusts from Antarctica, and found that volcanoes under its glaciers were vital in delivering iron to the ocean during the last ice age.

Today, glacial meltwaters from Greenland and the Antarctic peninsula supply iron both in solution and as tiny particles (less than 0.0001mm in diameter), which are readily consumed by plankton. Where glaciers meet bedrock, minute organisms can live in pockets of relatively warm water. They are able to extract “food” from the rock, and in doing so release iron, which then can be carried by underwater rivers to the sea.

Volcanic eruptions under the ice can create underwater subglacial lakes, which, at times, discharge downstream large masses of water that travel to the ice margin and beyond, carrying with them iron in particle and in solution.

The role of melting ice in climate change is as yet poorly understood. It’s particularly pertinent as scientists predict the imminent collapse of part of the Larsen C ice shelf.

Researchers are also investigating how to reproduce natural iron fertilisation in the Southern Ocean and induce algal blooms. By interrogating the volcanic archive, we learn more about the effect that iron fertilisation from meltwater has on global temperatures.

A polished wafer of the subglacial calcites. The translucent, crystalline layers formed while in pockets of water, providing nourishment to microbes. The opaque calcite with rock fragments documents a period when waters discharged from a subglacial lake formed by a volcanic eruption, carrying away both iron in solution and particles of iron.
Supplied

The Last Glacial Maximum

During the Last Glacial Maximum, a period 27,000 to 17,000 years ago when glaciers were at their greatest extent worldwide, the amount of CO2 in the atmosphere was lowered to 180 parts per million (ppm) relative to pre-industrial levels (280 ppm).

Today we are at 400 ppm and, if current warming trends continue, a point of no return will be reached. The global temperature system will return to the age of the dinosaurs, when there was little difference in temperature from the equator to the poles.

If we are interested in providing a habitable planet for our descendants, we need to mitigate the quantity of carbon in the atmosphere. Blooms of plankton in the Southern Ocean boosted by iron fertilisation were one important ingredient in lowering CO2 in the Last Glacial Maximum, and they could help us today.

The Last Glacial Maximum had winds that spread dust from deserts and icebergs carrying small particles into the Southern Ocean, providing the necessary iron for algal blooms. These extreme conditions don’t exist today.

Hidden volcanoes

Neither dust nor icebergs alone, however, explain bursts of productivity recorded in ocean sediments in the Last Glacial Maximum. There was another ingredient, only discovered in rare archives of subglacial processes that could be precisely dated to the Last Glacial Maximum.

Loss of ice in Antartica’s Dry Valleys uncovered rusty-red crusts of calcite plastered on glacially polished rocks. The calcites have tiny layers that can be precisely dated by radiometric techniques.

A piece of subglacial calcite coating pebbles. This suggests that the current transporting the pebbles was quite fast, like a mountain stream. The pebbles were deposited at the same time as the opaque layer in the calcite formed.
Supplied

Each layer preserves in its chemistry and DNA a record of processes that contributed to delivering iron to the Southern Ocean. For example, fluorine-rich spherules indicate that underwater vents created by volcanic activity injected a rich mixture of minerals into the subglacial environment. This was confirmed by DNA data, revealing a thriving community of thermophiles – microorganisms that live in very hot water only.

Then, it became plausible to hypothesise that volcanic eruptions occurred subglacially and formed a subglacial lake, whose waters ran into an interconnected system of channels, ultimately reaching the ice margin. Meltwater drained iron from pockets created where ice met bedrock, which then reached the ocean – thus inducing algal blooms.

We dated this drainage activity to a period when dust flux does not match ocean productivity. Thus, our study indicates that volcanoes in Antarctica had a role in delivering iron to the Southern Ocean, and potentially contributed to lowering CO2 levels in the atmosphere.

The ConversationOur research helps explain how volcanoes act on climate change. But it also uncovers more about iron fertilisation as a possible way to mitigate global warming.

Silvia Frisia, Associate Professor, School of Environmental and Life Sciences , University of Newcastle

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

Zoos aren’t Victorian-era throwbacks: they’re important in saving species



File 20170614 21315 17v6lu
A meerkat at the National Zoo and Aquarium in Canberra. The Zoo has recently announced an expansion that will double its size.
AAP Image/Stefan Postles

Alienor Chauvenet, The University of Queensland

The National Zoo and Aquarium in Canberra recently announced a new expansion that will double its size, with open range space for large animals like white rhinos and cheetahs.

As well as improving visitors’ experience, the expansion is touted as a way to improve the zoo’s breeding program for threatened animals. However, zoos have received plenty of criticism over their capacity to educate, conserve, or even keep animals alive.

But while zoos began as 19th-century menageries, they’ve come a long way since then. They’re responsible for saving 10 iconic species worldwide. Without captive breeding and reintroduction efforts, there might be no Californian Condor or Przewalski’s Horse – the only truly wild horse – left in the wild.

Australian zoos form part of a vital global network that keeps our most vulnerable species alive.

What is the role of zoos for conservation?

Although Canberra Zoo is relatively new compared with others in Australia – Melbourne zoo, for example, was opened in 1862 – it adds to a collection of conservation-orientated establishments.

In Australia, Taronga Conservation Society Australia, the Royal Melbourne Zoological Gardens, Adelaide Zoo and Perth Zoo are all members of the World Association of Zoos and Aquariums (WAZA). WAZA is an international organisation that aims to guide and support zoos in their conservation missions, including captive breeding, reintroductions into the wild, habitat restoration, and genetic management.

From the perspective of nature conservation, zoos have two major roles: educating the public about the plight of our fauna, and contributing to species recovery in the wild.

Conservation education is deeply embedded in the values of many zoos, especially in Australia. The evidence for the link between zoo education and conservation outcomes is mixed, however zoos are, above anybody else, aimed at children. Evidence shows that after guided experiences in zoos children know more about nature and are more likely to have a positive attitude towards it. Importantly, this attitude is transferable to their parents.

Zoos contribute unique knowledge and research to support field conservation programs, and thus species recovery. In Australia, zoos are directly involved in monitoring of free-ranging native fauna and investigations into emerging diseases. Without zoos many fundamental questions about a species’ biology could not be answered, and we would lack essential knowledge on animal handling, husbandry and care.

Through captive breeding, zoos can secure healthy animals that can be introduced to old or new habitats, or bolster existing wild populations. For example, a conservation manager at Taronga Zoo told me they’ve released more than 50,000 animals that were either bred on-site or rehabilitated in their wildlife hospitals (another important function of zoos).

Criticisms of captive breeding programs

The critics of captive breeding as a conservation strategy raise several concerns. Captive bred population can lose essential behavioural and cultural adaptations, as well as genetic diversity. Large predators – cats, bears and wolves – are more likely to be affected.

Some species, such as frogs, do well in captivity, breed fast, and are able to be released into nature with limited or no training. For others, there is usually a concerted effort to maintain wild behaviour.

There’s a higher chance of disease wiping out zoo populations due to animal proximity. In 2004 the largest tiger zoo in Thailand experienced an outbreak of H5N1 bird flu after 16 tigers were fed contaminated raw chicken; ultimately 147 tigers died or were put down.

However, despite these risks, research shows that reintroduction campaigns improve the prospects of endangered species, and zoos can play a crucial role in conservation. Zoos are continually improving their management of the genetics, behaviour and epidemiology of captive populations.

They are the last resort for species on the brink of extinction, such as the Orange-bellied Parrot or the Scimitar-horned Oryx, and for those facing a threat that we cannot stop yet, such as amphibians threatened by the deadly Chytrid fungus.

Orange-bellied parrots are ranked among the most endangered species on the planet – their survival depends on zoos.
Chris Tzaros/AAP

Zoos need clear priorities

A cost-benefit approach can help zoos prioritise their actions. Taronga, for example, uses a prioritisation system to decide which projects to take on, with and without captive breeding. Their aim is to a foresee threats to wildlife and ecosystems and implement strategies that ensure sustainability.

Developing prioritisation systems relies on clearly defined objectives. Is there value in keeping a species in captivity indefinitely, perhaps focusing only on education? Is contributing to a wild population the end goal, requiring both education and active conservation?

Once this is defined, zoos can assess the benefit and costs of different actions, by asking sometimes difficult questions. Is a particular species declining in the wild? Can we secure a genetically diverse sample before it is too late? Will capturing animals impact the viability of the wild population? How likely is successful reintroduction? Can we provide enough space and stimulation for the animals, and how expensive are they to keep?

Decision science can help zoos navigate these many factors to identify the best species to target for active captive conservation. In Australia, some of the rapidly declining northern mammals, which currently do not have viable zoo populations, could be a good place to start.

Partnerships with governmental agencies, universities and other groups are essential to all of these activities. Zoos in Australia are experts at engaging with these groups to help answer and address wildlife issues.


The ConversationAlienor Chauvenet would like to acknowledge the contribution of Hugh Possingham to this article, and thank Nick Boyle and Justine O’Brien from Taronga Conservation Society Australia for the information they provided.

Alienor Chauvenet, Postdoctoral Research Fellow, The University of Queensland

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

Critical backbenchers push back on Finkel clean energy target plan



File 20170613 30327 yxk821
Josh Frydenberg’s task of garnering broad support for the Finkel scheme is proving to be more difficult than expected.
Lukas Coch/AAP

Michelle Grattan, University of Canberra

A sizeable slice of his backbench has sent Malcolm Turnbull a forceful message that his road to implementing the clean energy target (CET) proposed by the Finkel inquiry will be rocky even within his own ranks.

After Energy Minister Josh Frydenberg gave an extensive briefing on the Finkel plan to the Coalition partyroom on Tuesday morning, MPs later reconvened for nearly three hours of questions and debate.

About one-third of the 30-32 who spoke expressed misgivings, according to Coalition sources. There was broad support from another third. The rest didn’t express a firm view, asking questions and seeking more information.

The report from the panel led by Chief Scientist Alan Finkel says a CET “will encourage new low emissions generation [below a threshold level of carbon dioxide per megawatt hour] into the market in a technology neutral fashion”.

A key issue will be where the government, which is disposed to adopt the Finkel plan, sets the threshold. It is clear that to accommodate the Nationals and a section of the Liberal Party it will have to be at a level that allows for the inclusion of “clean” coal.

The meeting was to gauge backbench views ahead of cabinet considering the report. Ministers, apart from the minister with carriage of the issue, don’t speak on these occasions.

Tony Abbott, who had publicly flagged his belief that the Finkel scheme represents a tax on coal, spoke strongly at the meeting.

The degree of pushback against a CET was stronger than had been anticipated, given the intense lobbying of the backbench that Frydenberg had done ahead of the meeting.

Frydenberg said afterwards: “I want to emphasise that this meeting was not making any decisions about Dr Finkel’s proposal. Rather, it was an information-gathering session.”

A common theme from backbenchers was that it was vital to be able to be confident the Finkel plan would make energy more affordable. A number of MPs, especially from outer suburban and regional areas, said affordability was what mattered most to their electorates.

Some questioned the Finkel modelling showing that prices would fall. The chairman of the backbench environment committee, Craig Kelly, said: “If you believe that you can lower prices by replacing existing coal-fired generation with higher-cost renewables, then I have a harbour bridge to sell you.”

Concern was expressed about the place of coal, and there was criticism of Finkel’s projection of an effective renewable energy target of 42% by 2030. Some backbenchers believed it would take the Coalition too close to Labor, which has a 50% target. There were also queries about the status of the Paris targets.

But Frydenberg told the ABC: “There was an overwhelming feeling among those in the party room tonight that business-as-usual is not an option.”

Asked on 7.30 “are you going to be able to get your colleagues to agree to support a clean energy target?,” Frydenberg replied: “It is too early to say.”

Finkel met with the government’s backbench environment committee on Tuesday to explain his plan and answer questions.

Frydenberg conceded that backbenchers “are concerned about the future of coal”. But he flatly rejected the Abbott suggestion that the Finkel plan amounted to a tax on coal, saying it was “absolutely not”.

“Dr Finkel has made it very clear he is not putting in place any prohibitions on coal or any form of generation capacity. He is putting in place incentives for lower emission generation. It is not a price on carbon or a tax on coal.”

The CET had “similarities to what John Howard put forward back in 2007”, Frydenberg said – a point he made in his briefing to the party meeting.

Deputy Prime Minister Barnaby Joyce also slapped down Abbott’s proposition that the CET amounted to a tax on coal, telling Sky that “Mr Abbott’s entitled to his opinion” but “there is no penalty placed on coal.

The Conversation“There is an advantage that is placed on those that are below the line. An advantage, because they get a section of a permit, which is like a payment. Those above the lines don’t … I suppose ipso facto it could be seen as not having the same advantage.”

https://www.podbean.com/media/player/icjdu-6b9a25?from=site&skin=1&share=1&fonts=Helvetica&auto=0&download=0

Michelle Grattan, Professorial Fellow, University of Canberra

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

The Finkel Review at a glance


Madeleine De Gabriele, The Conversation; Michael Hopkin, The Conversation, and Wes Mountain, The Conversation

The long-awaited report from Chief Scientist Alan Finkel into Australia’s National Electricity Market was released today.

The key recommendation is the adoption of a Clean Energy Target. This mandates that energy retailers provide a certain amount of their electricity from “low-emissions” generators – sources that produce emissions below a threshold level of carbon dioxide per megawatt.

Crucially, Dr Finkel has not made a recommendation as to the precise threshold or the number of certificates to be issued, saying:

The Panel acknowledges that the specific emissions reduction trajectory that should be set for the electricity sector is a question for governments.

The ConversationAt a minimum, the electricity sector should have a trajectory consistent with a direct application of the national target of 26-28% reduction on 2005 levels by 2030, as per Australia’s international obligations under the Paris Agreement.



Independent Review into the Future Security of the National Electricity Market/The Conversation, CC BY-ND

Madeleine De Gabriele, Deputy Editor: Energy + Environment, The Conversation; Michael Hopkin, Environment + Energy Editor, The Conversation, and Wes Mountain, Deputy Multimedia Editor, The Conversation

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

Explainer: what is a ‘low emissions target’ and how would it work?


Frank Jotzo, Australian National University

The main job of the Finkel Review, to be released this week, is to set out ways to reform the National Electricity Market (NEM) to ensure it delivers reliable and affordable power in the transition to low-carbon energy. Yet most of the attention has been focused on what type of carbon-reduction scheme Australia’s chief scientist, Alan Finkel, will recommend.

The expectation is that he will advocate a “low emissions target” (LET), and it looks like industry is getting behind this.

That would be instead of an emissions intensity scheme (EIS), which had been supported by much of industry as well as regulators and analysts, but the government rejected this.

Both types of scheme are second-best approaches to a carbon price. They can have similar effects depending on their design and implementation, although an EIS would probably be more robust overall.

How a LET might work

A LET would give certificates to generators of each unit of electricity below a threshold carbon intensity. Electricity retailers and industry would be obliged to buy the certificates, creating a market price and extra revenue for low-emission power generators.

How many certificates get allocated to what type of power generator is an important design choice. Government would also determine the demand for the certificates, and this defines the overall ambition of the scheme.

At its core, the scheme would work rather like the existing Renewable Energy Target, which it would replace. But the new scheme would also include some rewards for gas-fired generators, and perhaps even for coal-fired generators that are not quite as polluting as others. The question is how to do this.

A simple but crude way of implementing a LET would be to give the same number of certificates for every megawatt hour (MWh) of electricity generated using technologies below a benchmark level of emissions intensity. In practice, that would be renewables and gas. In principle, the scheme could include nuclear power as well as coal plants with carbon capture and storage, but neither exists in Australia, nor are they likely to be built.

Such a simple implementation would have two drawbacks. One, it would create a strong threshold effect: if your plant is slightly above the benchmark, you’re out, slightly below and you’re in. Two, it would give the same reward to gas-fired generators as to renewables, which is inefficient from the point of view of emissions reduction.

A better way is to scale the amount of certificates issued to the emissions intensity of each plant.

If the benchmark was 0.7 tonnes of carbon dioxide per MWh of electricity (as some media reports have predicted), then a gas plant producing 0.5 tonnes of CO₂ per MWh would get 0.2 certificates per MWh generated. A wind or solar farm, with zero emissions, would receive 0.7 certificates per MWh generated.

The benchmark could also be set at a higher level, potentially so high that all power stations get certificates in proportion to how far below the benchmark they are. For example, a benchmark of 1.4 tonnes CO₂ per MWh would give 1.4 certificates to renewables, 0.9 certificates to the gas plant, 0.5 certificates to an average black coal plant and 0.2 certificates to a typical brown coal plant.

Including existing coal plants in the LET in this way would create an incentive for the sector to move towards less polluting generators. It would thus help to reduce emissions from the coal fleet, and perhaps pave the way for the most polluting plants to be retired earlier. But the optics would not be good, as the “low emissions” mechanism would be giving credits to coal.

Whichever way certificates are distributed, the government also has to specify how many certificates electricity retailers need to buy. Together with the benchmark and with how electricity demand turns out, this will determine the emissions intensity of overall power supply. The benchmark would need to decline over time; alternatively, the amount of certificates to be bought could be increased.

The price of LET certificates would depend on all of these parameters, together with the cost of energy technologies, and industry expectations about the future levels of all of these variables. As the experience of the RET has shown, these can be difficult to predict.

Low emissions target vs emissions intensity scheme

An emissions intensity scheme (EIS) is the proposal that in recent times had the broadest support in the policy debate. Finkel’s preliminary report referenced it and the Climate Change Authority earlier put significant emphasis on it. But it got caught in the internal politics of the Liberal-National Coalition and was ruled out.

Under an EIS, the government would set a benchmark emissions intensity, declining over time. Generators below the benchmark would be issued credits, whereas those running above the benchmark would need to buy credits to cover their excess emissions. Supply and demand set the price in this market.

Depending on how the parameters are set, the effects of a LET and an EIS on the power mix and on power prices would differ, but not necessarily in fundamental ways.

There are some key differences though. Under a LET, electricity retailers will need to buy certificates and not all power plants may be covered by a low-carbon incentive. Under an EIS, the higher-polluting plants buy credits from the cleaner ones, and all types of plants are automatically covered. The EIS market would be closely related to the wholesale electricity market, with the same participants, whereas a LET market would be separate and distinct, like the RET market now.

Further, the benchmark in an EIS directly defines the emissions intensity of the grid and its change over time. Not so for the benchmark in a LET. A LET will also require assumptions about future electricity demand in setting the total amount of credits that should be purchased – and bear in mind that the estimates used to calibrate the RET were wildly off the mark.

What’s more, an EIS might present a chance to circumvent the various special rules and exemptions that exist in the RET, and which might be carried over to the LET.

Politics vs economics

Neither a LET nor an EIS provides revenue to government. Since the demise of Australia’s previous carbon price this has often been considered desirable politically, as it avoids the connotations of “carbon tax”. But economically and fiscally it is a missed opportunity.

Globally, most emissions trading schemes generate revenue that can be used to cut other taxes, help low-income households, or pay for clean energy research and infrastructure.

An economically efficient system should make carbon-based electricity more expensive, which encourages energy consumers to invest in energy-saving technology. Both a LET and an EIS purposefully minimise this effect, and thus miss out on a key factor: energy efficiency.

Ambition and confidence

More important than the choice of mechanism is the level of ambition and the political durability of the policy.

Bringing emissions into line with the Paris climate goals will require fundamental restructuring of Australia’s power supply. Coal would need to be replaced well before the end of the lifetime of the current plants, probably mostly with renewables.

To prompt large-scale investment in low-carbon electricity, we need a reliable policy framework with a genuine and lasting objective to reduce emissions. And investors need confidence that the NEM will be governed by rules that facilitate this transition.

Of any policy mechanism, investors will ask the hard questions: what will be its actual ambition and effects? Would the scheme survive a change in prime minister or government? Would it stand up to industry lobbying? Investor confidence requires a level of predictability of policy.

The ConversationIf a LET were supported by the government and acceptable to the Coalition backbench, and if the Labor opposition could see it as a building block of its climate policy platform, then the LET might be a workable second best, even if there are better options. Over the longer term, it could be rolled into a more comprehensive and efficient climate policy framework.

Frank Jotzo, Director, Centre for Climate Economics and Policy, Australian National University

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