Tag Archives: greenhouse gases

Methyl Bromide and Strawberries .. Shock .. Horror .. Oh, Wait a Minute.

The Conversation

Ian Musgrave, Senior lecturer in Pharmacology at University of Adelaide

There was an article on the ABC site this morning which gave us this alarming headline “Pesticide banned worldwide still used to grow 70pc of Australian strawberries”. Shocking!

Except, well, there were a few teeny tiny but important details missing. Like the fact that the rest of the world is still using the “banned” pesticide too.

Methyl Bromide (the substance involved) has been withdrawn worldwide under the Montreal protocol as it is a potent greenhouse gas (not because of toxicity, as many people have assumed from the headlines). However, world wide, there are exemptions for the use of methyl bromide as a fumigant for quarantine and production purposes (QPS) and some special (critical use) exemptions, it’s not just us. In 2005 Australia, stopped the use of methyl bromide for all but the exempt QPS uses, and for a few uses for which there was no suitable alternative to methyl bromide.

Just like the rest of the world.

In 2012 around 12,000 metric tonnes of methyl bromide were used around the world for various QPS and critical exemption purposes, Australia’s agricultural use was 32 tonnes at this time (Japan’s was 216 metric tonnes and the US 923 metric tonnes for comparison). Critical use exemptions, the ones that allow the strawberry farmers to fumigate their soil, must be applied for each year.

Like everyone else in the world, Australia developed plans to phase out the remaining methyl bromide use. Since 2005, when methyl bromide use in general was phased out, Australia has been replacing methyl bromide in the critical use exemption and (to a more limited extent) QPS categories with alternatives, dropping from 112 metric tonnes in 2005 to 32 metric tonnes in 2015.

Methyl bromide is an important pesticide fumigant, and is used to kill pathogens and pests in imported produce and some produce for export. Finding alternatives is not straight forward, for example, phosphine, one of the alternative fumigants, is highly flammable, so new handing procedures are needed to combat the risk of fire.

While reducing the amount of methyl bromide entering the atmosphere is important, the significant risk to the Australian biota and agricultural production from invasive pests and pathogens has to be weighted against the fact that human produced brominated compounds represent less than 0.03% of the total halogens released into the atmosphere, and that unlike CFC’s, which last in the atmosphere for decades, methyl bromide’s half life in the atmosphere is less than a year.

Given the relatively small impact of methyl bromide, and the continuing reduction of methyl bromide (see here for a comparison of the progress and the contribution of the US vs the rest of the world), Shock! Horror! headlines about Australia’s use for strawberries are unwarranted.

In the strawberry growing industry, methyl bromide is used to destroy pathogens and pests in the soil the strawberry runners are planted in. In Queensland and Tasmania, methyl bromide has been replaced. However, for the soils in the Victorian strawberry growing areas, the alternative fumigants aren’t as effective.

Other fumigants are being researched, but it takes time to find something that is reasonably safe, reasonably cheap and effective. One of the potential replacements, methyl iodide, has been withdrawn from the market, so the hunt is still on for a viable replacement. It may be that we have to grow our strawberries under soil-less conditions to stop disease and pest losses.

So, like all other countries, Australia has phased out methyl bromide, except for quarantine and other critical uses for which there is no effective alternative (again, just like other countries). Since 2005 we have systematically reduced the amount of methyl bromide for these uses, and are undertaking research to reduce the amount even further.

Oh, and in case you are worried that methyl bromide contaminates the strawberries, methyl bromide breaks down in the soil, and the strawberries that grow much later do not come into contact with it. There is no toxicity issue here at all.

The ConversationThis article was originally published on The Conversation. (Reblogged by permission). Read the original article.
 

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For this generation, and the next, it’s time to bring back the carbon tax

The Conversation

By Max Corden, University of Melbourne

Australian Treasurer Joe Hockey will release the Intergenerational Report on Thursday, and has invited Australians to join in a conversation about the economy and the challenges facing the budget.

I’d like to argue the case for bringing back the carbon tax.

Tony Abbott, when leader of the Opposition, promised to repeal the carbon tax brought in by Prime Minister Julia Gillard. And he has fulfilled his promise.

Now circumstances have changed: the budget deficit and public debt have turned out to be important problems in the eyes of the government because of the somewhat unexpected decline in export prices. So Abbott, or his successor as prime minister, would be justified in re-imposing this tax.

The revenue from a carbon tax could make a significant contribution to dealing with the deficit problem. Of course, it would not be enough, and, as is well known, other measures or reforms to generate revenue for the government are available and certainly needed.

The carbon tax as a burden

Prime Minister Abbott certainly convinced his fellow Australians that this “great big new tax” would be a burden. But all taxes impose burdens or costs somewhere, whether on companies or individuals. One might reflect that, in current budgetary circumstances a “big new tax,” and perhaps more than one, is just what doctor Hockey ordered.

The carbon tax was paid by numerous businesses, but this did not mean they carried the final “burden”. Mostly they would have passed it on to their customers, both households and businesses. Essentially it might be regarded as a fossil energy tax.

When the tax was repealed Abbott argued households would benefit on average by A$550 a year, with gas prices to fall by 7% and electricity prices by 9%. His much-repeated and persuasive message was that the carbon tax raised the cost of living and this was “toxic” and “has been hurting ordinary people”. He also argued a tax that raised energy prices would have led to job losses.

All this seemed very persuasive. The persuasion was reinforced by the fact that earlier – essentially from 2007 to 2010 – electricity prices had risen sharply for other reasons, essentially to pay for the high costs of excessive investment in networks (poles and wires). In many minds those price rises were mixed up with the expected effect of the carbon tax.

Where did the revenue go?

But Abbott never refers to the government revenue that was raised because of the carbon tax. Did the tax not have any beneficial effects for households or businesses to compensate for the directly adverse effects of the higher prices of energy? Where did this revenue go?

In fact, some of it was used to compensate firms that competed in international markets, while a substantial part compensated low income households through reductions in their income tax. The latter was an important element of the Gillard program. What was taken out of the income stream by the carbon tax at one point was put back by the compensation at another point. If there were job losses at one end, there would be job gains at the other. Furthermore, reducing income tax, at least in the low income ranges, would increase the incentives to seek work, a highly desirable economic effect.

Possibly some of the revenue led to greater government spending which benefited households. By ignoring all these offsetting revenue effects Abbott was able to conclude that the carbon tax had a severely adverse effect on incomes and employment. Did he really believe this?

At this point one might ask: what was the point of the whole exercise when funds were taken out of the economy at one end and put back at the other. The answer seems obvious. The carbon tax would produce market inducements that reduced harmful emissions of greenhouse gases. Of course, if one does not believe that climate change is a problem, or that Australia could make any difference, the whole business seems pointless. And if one assumes that nothing happens to the revenue, the tax would seem not just pointless but harmful.

Use the revenue to reduce the deficit?

In the event of the carbon tax being reinstated, the whole of the gross revenue might be used to reduce the budget deficit. It would not finance increased government spending. How much money would be available? According to official estimates, in the first two years of operation the carbon tax raised A$15.4 billion in gross revenue.

If the carbon tax revenue actually reduces the budget deficit without compensating tax or spending changes elsewhere, the benefit would then be in the future (when debt is lower than otherwise), while the return of the “big new tax” would indeed impose a present cost. Hockey would then get his deeply desired budget improvement but this would still be at odds with Abbott’s desire to avoid new taxes.

The economic impact of climate change

Australia has a group of “realists” who do not deny climate change, but argue Australia generates such a small proportion of the world’s harmful carbon emissions that we cannot make any difference anyway. So, why bother with a carbon tax?

We can make a difference, and, above all, it is in our interest that we do. We may not be able to directly affect world climate alone, but it certainly will affect us, so we must try and influence collective global action.

First there is the direct effect of climate change on Australia, and especially its coastline, as set out by the CSIRO. Likely effects include reduced rainfall in southern Australia, more extreme fire weather, adverse effects on the Great Barrier Reef, on coastal populations, and so on. Particularly important for Australia are increasing heatwaves. Heatwaves have killed more Australians than all other natural hazards combined.

Second, the rise of the sea level in association with severe weather events is likely to have a serious impact on Australia’s neighbouring islands and island countries, including Indonesia, with many of its population of 250 million people highly vulnerable.

For selfish reasons we need to use our maximum diplomatic influence to encourage other countries to take the necessary measures to drastically moderate or avoid climate change. And we can only do this if we set an example ourselves. A restoration of the carbon tax would be the first step.

Of course, eventually this might evolve into an Emissions Trading Scheme. In both cases carbon emissions will be discouraged and the government will receive revenue.


Editor’s note: Max will be answering questions between 10 and 11am on Thursday March 5. You can ask your questions about the article in the comments below.

The ConversationThis article was originally published on The Conversation. (Reblogged by permission). Read the original article.


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The rabbits of Christmas past: a present that backfired for Australia

The Conversation

By Andrew Bengsen, University of New England

On Christmas Day 1859, the Victoria Acclimatisation Society released 24 rabbits for hunting, to help settlers feel more at home.

Given the millions of dollars in damage to agricultural productivity that ensued, as well as the impacts on biodiversity as the rabbits bred and spread to cover 70% of the continent, this could be seen as Australia’s worst Christmas present.

Now, given our current climate change commitments, controlling rabbits could be “Santa’s little helper” in reducing greenhouse gas emissions.

In 2007, Australia committed to reduce its greenhouse gas emissions to at least 5% below 2000 levels, by the year 2020. This commitment remains central to our climate change policy, and we should expect greater emissions reduction targets in future if we comply with the international target of limiting global warming to plus 2 deg C.

Storing carbon in the land

There’s been plenty of talk of planting more trees. But case studies and evaluations of government programs such as Bushcare show that this is an expensive way to re-vegetate.

Instead, many people now recognise there are better ways to manage carbon across large areas. Livestock grazing and fire (such as “savanna burning”) are often cited as important factors to manage and enhance carbon storage in plants and soils across vast areas.

Some significant gains might also be achieved by reducing the damage caused by some of our most serious pest animals.

Eating us out of house, home and carbon

Rabbits are well known for their ability to strip grasslands bare and destroy the seedlings of woody shrubs and trees. Even in low numbers, rabbits can completely prevent some important woody species from regenerating.

Mulga woodlands, for example, cover vast tracts of inland Australia, and mulga trees are likely to be a very important carbon store in these areas. However, rabbit numbers as low as one animal per hectare can effectively stop the replacement of old trees by destroying seedlings.

Distribution of rabbits (orange, left) and mulga woodlands (green, right) across Australia. Rabbit data from West 2008.

Recently, Tarnya Cox and I reviewed the potential benefits of controlling rabbits and other invasive herbivores for reducing Australia’s greenhouse gas emissions. We unearthed a multitude of similar stories about the extensive damage that rabbits can cause to vegetation and ecosystem function, and how that may affect the ability of these systems to capture and store carbon.

Importantly, much of the damage that rabbits cause to the environment can be reversed.

In many areas, Mulga and other species flourished for the first time in 100 years after rabbit numbers were reduced by up to 95% in the 1990s by rabbit hemorrhagic disease virus (previously known as calicivirus).

Many other studies have also found sudden increases in plant growth after rabbit populations were reduced by disease or intensive conventional control.

A rabbit opportunity

Dying mulga tree and narrow-leaved fuchsia bush in a rangeland area degraded by rabbits and goats. Robert Henzell

The regeneration of Mulga and other woody species over broad areas can make significant contributions to our emissions reduction targets. Mulga and other arid zone acacias are long-lived, grow slowly, and have very dense wood. This means that mature trees can store large amounts of carbon for their size, and keep much of it locked up long after the death of the plant.

Regenerating Mulga woodlands in western Queensland and New South Wales are estimated to capture over half a tonne of carbon dioxide equivalent, per hectare per year, in woody biomass alone. This equates to about four air passengers travelling from Sydney to Brisbane per hectare of mulga woodlands.

Rabbits inhabit most of the 143 million hectares of Australia’s Mulga woodlands. If their populations can be controlled, then there is considerable potential for natural carbon sequestration to help us meet our greenhouse gas reduction targets.

Other invasive herbivores – such as camels and goats – can also reduce vegetation cover and plant carbon storage. However, we already have a solid understanding of the rabbit’s impact on the environment, and they are very widespread which means that their eradication could have large positive impacts.

How to control rabbits

Conventional rabbit control operations – such as warren destruction and poison baiting – can be more cost-effective at regenerating native vegetation, than planting more trees. This would be useful for the large areas of road-side reserves and stock routes which need revegetation. They rival the size of the National Park estate in terms of total area across south-eastern Australia.

These areas would be suitable for conventional rabbit control. Even a small increase in tree density due to rabbit control would help us achieve our greenhouse gas reduction targets. Rabbit control is often required to allow tree plantings to establish and flourish.

A rabbit feeds on a planted tree surrounded by a tree guard, despite an apparent abundance of green vegetation outside the tree guard. Mark Hillier, Invasive Animals Cooperative Research Centre, Author provided

Of course, there are many challenges in reducing the damage caused by rabbits, and improve our chances of achieving our greenhouse gas reduction targets. Most importantly, we need accurate estimates of the effect of rabbit control on natural carbon sequestration. We also need a means of monitoring actual carbon sequestration amounts, that complies with the stringent carbon accounting rules of the Kyoto Protocol.

Another major challenge is the declining effectiveness of rabbit hemorrhagic disease. Fortunately, a major cooperative research program is already underway to counter the virus’ diminishing effect, though biological control alone cannot be expected to completely mitigate rabbit impacts.

As we hark back to that fateful Christmas Day in 1859, a future of climate uncertainty, agricultural hardship and the loss of our unique biodiversity, we must be prepared to act on these challenges.

The ConversationThis article was originally published on The Conversation. (Reblogged with permission). Read the original article.

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It’s time for environmentalists to give nuclear a fair go

The Conversation

By Barry W. Brook, University of Tasmania and Corey Bradshaw
Should nuclear energy be part of Australia’s (and many other countries’) future energy mix? We think so, particularly as part of a solution to reduce greenhouse gas emissions and prevent dangerous climate change.

Is the future of biodiversity conservation nuclear?
Corey Bradshaw and Barry Brook, CC BY-NC

But there are other reasons for supporting nuclear technology. In a paper recently published in Conservation Biology, we show that an energy mix including nuclear power has lowest impact on wildlife and ecosystems — which is what we need given the dire state of the world’s biodiversity.

In response, we have gathered signatures of 66 leading conservation scientists from 14 countries in an open letter asking that the environmental community:

weigh up the pros and cons of different energy sources using objective evidence and pragmatic trade-offs, rather than simply relying on idealistic perceptions of what is ‘green’.

Energy demand is rising

Modern society is a ceaseless consumer of energy, and growing demand won’t stop any time soon, even under the most optimistic energy-efficiency scenario.

Although it goes without saying that we must continue to improve energy efficiency in the developed world, the momentum of population growth and rising living standards, particularly in the developing world, means we will continue to need more energy for decades to come. No amount of wishful thinking for reduced demand will change that.

But which are the best forms of energy to supply the world, and not add to the biodiversity crisis?

Assessing our energy options

In short, the argument goes like this.

To avoid the worst ravages of climate change, we have to decarbonise fully (eliminate net carbon emissions from) the global electricity sector. Wildlife and ecosystems are threatened by this climate disruption, largely caused by fossil-fuel derived emissions.

But they are also imperilled by land transformation (i.e., habitat loss) caused in part by other energy sources, such as flooded areas (usually forests) for hydro-electricity and all the associated road development this entails, agricultural areas needed for biofuels, and large spaces needed for wind and solar farms.

Energy density of different fuels. This infographic shows the amount of energy embodied in uranium, coal, natural gas and a chemical battery, scaled to provide enough energy for a lifetime of use in the developed world. Shown are the amount of each source needed to provide same amount of energy, equivalent to 220 kWh of energy per day for 80 years.
Barry Brook and Corey Bradshaw

In the paper, we evaluated land use, emissions, climate and cost implications of three different energy scenarios:

  • a “business as usual” future dominated by fossil fuels
  • a high renewable-energy mix excluding nuclear promoted by Greenpeace
  • an energy mix with a large nuclear contribution (50% of energy mix) plus a balance of renewable and fossil-fuel sources with carbon-capture-and-storage.

We then ranked seven major energy types: coal, gas, nuclear, biomass, hydro, wind, and solar based on economic and safety costs, and environmental benefits. We also tested the sensitivity of these rankings to bias stemming from philosophical ideals.

For instance, if you were most concerned about pursuing low carbon emissions, you might weight that criterion twice as heavily in the analysis as the lowest-cost option.

When compared objectively with alternatives, nuclear power performs as well or better that other options in terms of safety, cost, scaleability, reliability, land transformation and emissions. And overall, the mix including a substantial role for nuclear performed better than the other scenarios.

Although our analysis was based on existing nuclear designs, we were most excited about the advantages offered by next-generation nuclear power now under construction in Russia and China.

If deployed widely, this technology could provide emissions-free electricity, by recycling a highly-concentrated energy source in a way that consumes waste and minimises impacts to biodiversity compared to other energy sources.

A sustainable nuclear fuel cycle that ‘eats’ nuclear waste to produce abundant zero-carbon electricity and no long-lived byproducts.
Barry Brook and Corey Bradshaw

0% fossil fuels, not 100% renewables

Ultimately, there is no perfect energy source. Conservation professionals and environmental advocates need to take an evidence-based approach to consider carefully the combined effects of energy mixes on biodiversity conservation.

Much as leading climate scientists recently advocated the development of safe, next-generation nuclear energy systems to combat global climate change, we argue that only by leaving our energy options open can we maximise our chance of conserving biodiversity and natural habitats during this century and beyond.

For example, the use of nuclear energy for electricity generation is prohibited federally within Australia under the Environmental Protection and Biodiversity Conservation Act 1999 (see section 140A). This needs to change if we are serious about maximising our changes of displacing fossil fuels.

There is strong evidence for supporting advanced nuclear power systems with complete fuel recycling as part of a portfolio of sustainable energy technologies, that also includes appropriate use of renewables, energy storage and energy efficiency.

We must accept that trade-offs and compromises are inevitable and require advocating energy mixes that minimise net environmental damage.

A key message is that the ideal mix of nuclear and renewables will be regionally dependent – being modified by, for example, available land area and renewable potential – and should be compared objectively without prejudice or preconceived notions. The environmentalist mantra on energy needs shift from “100% renewables” to “0% fossil fuels”. That should be the primary goal.

It is time that conservationists make their voices heard in this policy arena.


This article was originally published on The Conversation. (Reblogged by permission). Read the original article.
 

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