Lichens may be a symbiosis of three organisms; a new Order of fungus named


Susan Lawler, La Trobe University

There is big news in the world of lichens. These slow growing organisms have long been known to be a collaboration between a fungus and a photosynthetic algae or cyanobacteria. A recent publication in Science may have changed all that.

Researchers have discovered another fungus living in the tissues of lichens. Unlike the dominant fungal type, also known as Ascomycetes, the new fungus is a Basidiomycete that exists as single cells, more closely related to yeast. A survey has found these new fungal cells in 52 genera of lichens, raising the prospect of a previously undetected third partner in the ancient symbiosis.

Interestingly, despite many attempts, it has never been possible to synthesise lichen in the laboratory by combining the two known partners, and now we might know why. Lichenologists have always recognised a mycobiont (fungal partner) and a photobiont (the photosynthetic organism that makes food) and now we may have to find a word for the new fungal component.

Toby Spribille of the University of Graz in Austria and his colleagues were trying to understand why two species of lichen that were made up of the same species of mycobiont and photobiont were differently coloured and contained varying levels of a toxin known as vulpinic acid.

Using an approach that examined the messenger RNAs produced by the organism, they tried to find the genes that produced the toxin, but neither the mycobiont or the photobiont had genes that matched the transcript. By broadening their search to include other types of fungi, they found genes belonging to a rare fungus called a Cystobasidiomycete.

Unable to see the cells responsible for this unusual finding, they used fluorescent in situ hybridisation (FISH) to light up cells containing genes for the algae, the ascomycete and the cystobasidiomycete. By linking different colours to each organism, they produced videos showing the distribution of each cell type. The new fungus existed as single cells inside the cortex, where it may play a structural role as well as providing chemical defence.

It is hard to overstate the importance of this discovery. Spribille was quoted in the New York Times as saying that lichens are as diverse as vertebrates. And yet we did not know until now that the symbiosis that allows lichens to exist has more than two partners.

The authors have described a new order of fungi called the Cyphobasidiales. It is not everyday that scientists are able to add new taxa at such a high level. It is like discovering the Primates. By creating a phylogenomic tree and applying a molecular clock, they found that this group has been around for 200 million years, probably since the beginning of lichens.

The 52 genera that have been examined thus far are widespread (on six continents) but are still a small portion of lichens, so there may be more to discover. Interestingly, the continent that is not included is Australia. Perhaps we do not have enough lichenologists to provide samples to the international community. It is possible that some lichens do not contain this new order of fungi. What is not in doubt is that now scientists will be looking at lichens more closely.

Lichens grow very slowly. Individuals can be hundreds or even thousands of years old. Now it seems that our knowledge of this ancient symbiosis has also grown slowly, as it has taken 150 years to find the third partner.

Given the sophisticated techniques required to untangle this conundrum, I suppose it was not possible to know about the silent partner, the yeast in the mix, until now. But it certainly gives rise to some exciting science.

The Conversation

Susan Lawler, Senior Lecturer, Department of Ecology, Environment and Evolution, La Trobe University

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

The $8.2 billion water bill to clean up the Barrier Reef by 2025 – and where to start


John Rolfe, CQUniversity Australia

In 2015, the Australian and Queensland governments agreed on targets to greatly reduce the sediment and nutrient pollutants flowing onto the Great Barrier Reef.

What we do on land has a real impact out on the reef: sediments can smother the corals, while high nutrient levels help to trigger more regular and larger outbreaks of crown-of-thorns starfish. This damage leaves the Great Barrier Reef even more vulnerable to climate change, storms, cyclones and other impacts.

Dealing with water quality alone isn’t enough to protect the reef, as many others have pointed out before. But it is an essential ingredient in making it more resilient.

The water quality targets call for sediment runoff to be reduced by up to 50% below 2009 levels by 2025, and for nitrogen levels to be cut by up to 80% over the same period. But so far, detailed information about the costs of achieving these targets has not been available.

Both the Australian and Queensland governments have committed more funding to improve water quality on the reef. In addition, the Queensland government established the Great Barrier Reef Water Science Taskforce, a panel of 21 experts from science, industry, conservation and government, led by Queensland Chief Scientist Geoff Garrett and funded by Queensland’s Department of Environment and Heritage Protection.

New work commissioned by the taskforce now gives us an idea of the likely cost of meeting those reef water quality targets.

This groundbreaking study, which drew on the expertise of water quality researchers, economists and “paddock to reef” modellers, has found that investing A$8.2 billion would get us to those targets by the 2025 deadline, albeit with a little more to be done in the Wet Tropics.

That A$8.2 billion cost is half the size of the estimates of between A$16 billion and A$17 billion discussed in a draft-for-comment report produced in May 2016, which were reported by the ABC and other media.

Those draft figures did not take into account the reductions in pollution already achieved between 2009 and 2013. They also included full steps of measures that then exceeded the targets. A full review process identified these, and now this modelling gives a more accurate estimate of what it would cost to deliver the targets using the knowledge and technology available today.

A future for farming

Importantly, the research confirms that a well-managed agricultural sector can continue to coexist with a healthy reef through improvements to land management practices.

Even more heartening is the report’s finding that we can get halfway to the nitrogen and sediment targets by spending around A$600 million in the most cost-effective areas. This is very important because prioritising these areas enables significant improvement while allowing time to focus on finding solutions that will more cost-effectively close the remaining gap.

Among those priority solutions are improving land and farm management practices, such as adopting best management practices among cane growers to reduce fertiliser loss, and in grazing to reduce soil loss.

While these actions have been the focus of many water quality programs to date, much more can be done. For example, we can have a significant impact on pollutants in the Great Barrier Reef water catchments by achieving much higher levels of adoption and larger improvements to practices such as maintaining grass cover in grazing areas and reducing and better targeting fertiliser use in cane and other cropping settings. These activities will be a focus of the two major integrated projects that will result from the taskforce’s recommendations.

A new agenda

The new study, produced by environmental consultancy Alluvium and a range of other researchers (and for which I was one of the external peer reviewers), is significant because nothing on this scale involving the Great Barrier Reef and policy costings has been done before.

Guidelines already released by the taskforce tell us a lot about what we need to do to protect the reef. Each of its ten recommendations now has formal government agreement and implementation has begun.

Alluvium’s consultants and other experts who contributed to the study – including researchers from CQ University and James Cook University – were asked to investigate how much could be achieved, and at what price, by action in the following seven areas:

  1. Land management practice change for cane and grazing

  2. Improved irrigation practices

  3. Gully remediation

  4. Streambank repair

  5. Wetland construction

  6. Changes to land use

  7. Urban stormwater management

Those seven areas for potential action were chosen on the basis of modelling data and expert opinion as the most feasible to achieve the level of change required to achieve the targets. By modelling the cost of delivering these areas and the change to nutrient and sediments entering the reef, the consultants were able to identify which activities were cheapest through to the most expensive across five catchment areas (Wet Tropics, Burdekin, Mackay-Whitsunday, Fitzroy and Burnett Mary).

Alluvium’s study confirmed the water science taskforce’s recommendation that investing in some catchments and activities along the Great Barrier Reef is likely to prove more valuable than in others, in both an environmental and economic sense.

Some actions have much lower costs and are more certain; these should be implemented first. Other actions are much more expensive. Of the total A$8.2 billion cost of meeting the targets, two-thirds (A$5.59 billion) could be spent on addressing gully remediation in just one water catchment (the Fitzroy region). Projects with such high costs are impractical and highly unlikely to be implemented at the scale required.

The Alluvium study suggests we would be wise not to invest too heavily in some costly repair measures such as wetland construction for nutrient removal just yet – at least until we have exhausted all of the cheaper options, tried to find other cost-effective ways of reaching the targets, and encouraged innovative landholders and other entrepreneurs to try their hand at finding ways to reduce costs.

The value of a healthier reef

The A$8.2 billion funding requirement between now and 2025 is large, but let’s look at it in context. It’s still significantly less than the A$13 billion that the Australian government is investing in the Murray-Darling Basin.

It would also be an important investment in protecting the more than A$5 billion a year that the reef generates for the Australian economy and for Queensland communities.

The immediate focus should be on better allocating available funds and looking for more effective solutions to meet the targets to protect the reef. More work is still needed to ensure we do so.

If we start by targeting the most cost-effective A$1 billion-worth of measures, that should get us more than halfway towards achieving the 2025 targets. The challenge now is to develop new ideas and solutions to deliver those expensive last steps in improving water quality. The Alluvium report provides a valuable tool long-term to ensure the most cost-effective interventions are chosen to protect the Great Barrier Reef.


This article was written with contributions from Geoff Garrett, Stuart Whitten, Steve Skull, Euan Morton, Tony Weber and Christine Williams.

Read more of The Conversation’s Great Barrier Reef coverage, including articles by experts including Jon Brodie and Ove Hoegh-Guldberg.

The Conversation

John Rolfe, Professor of Regional Economic Development, School of Business and Law, CQUniversity Australia

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

Survey: two-thirds of Great Barrier Reef tourists want to ‘see it before it’s gone’


Annah Piggott-McKellar, The University of Queensland and Karen Elizabeth McNamara, The University of Queensland

The health of the Great Barrier Reef (GBR) is declining – a fact that has not been lost on the world’s media.

The issue has made international headlines and attracted comment from public figures such as US President Barack Obama and British businessman Richard Branson.

Some media outlets and tourism operators have sought to downplay the effects, presumably to try to mitigate the impact on tourism. The industry provides roughly 65,000 jobs and contributes more than A$5 billion a year to the Australian economy.

But our research suggests that the ailing health of the GBR has in fact given tourists a new reason to visit, albeit one that doesn’t exactly promise a long-term future.

When we surveyed hundreds of GBR tourists last year, 69% of them said they had opted to visit the reef “before it is gone” – and that was before the latest bleaching generated fresh international headlines about its plight.

‘Last chance’ tourism

“Last chance tourism” (LCT) is a phenomenon whereby tourists choose to visit a destination that is perceived to be in danger, with the express intention of seeing it before it’s gone.

The media obviously play a large role in this phenomenon – the more threatened the public perceives a destination to be, the bigger the market for LCT.

There’s a vicious cycle at play here: tourists travel to see a destination before it disappears, but in so doing they contribute to its demise, either directly through on-site pressures or, in the case of climate-threatened sites such as the GBR, through greenhouse gas emissions. These added pressures increase the vulnerability of the destination and in turn push up the demand for LCT still further.

The GBR often features on lists of tourist destinations to see before they disappear, alongside places such as Glacier National Park, the Maldives and the Galapagos Islands.

While the media have proclaimed the reef to be an LCT destination, it has not previously been empirically confirmed that tourists are indeed motivated to visit specifically because of its vulnerable status.

Surveying reef tourists

We wanted to find out how many of the GBR’s holidaymakers are “last chance” tourists. To that end, we surveyed 235 tourists visiting three major tourism hotspots, Port Douglas, Cairns and Airlie Beach, to identify their leading motivations for visiting.

We gave them a suggested list of 15 reasons, including “to see the reef before it is gone”; “to rest and relax”; “to discover new places and things”, and others. We then asked them to rate the importance of each reason on a five-point scale, from “not at all” to “extremely”.

We found that 69% of tourists were either “very” or “extremely” motivated to see the reef before it was gone. This reason attracted the highest proportion of “extremely” responses (37.9%) of any of the 15 reasons.

This reason was also ranked the fourth-highest by average score on the five-point scale. The top three motivations by average score were: “to discover new places and things”; “to rest and relax; and “to get away from the demands of everyday life”.

Our results also confirmed that the media have played a large role in shaping tourists’ perceptions of the GBR. The internet was the most used information source (68.9% of people) and television the third (54.4%), with word of mouth coming in second (57%).

Airlie Beach, a great spot for some last-chance tourism.
Damien Dempsey/Wikimedia Commons, CC BY

Our findings suggest that the GBR’s tribulations could offer a short-term tourism boost, as visitors flock to see this threatened natural wonder. But, in the long term, the increased tourism might exacerbate the pressure on this already vulnerable region – potentially even hastening the collapse of this ecosystem and the tourism industry that relies on its health.

This paradox is deepened further when we consider that many of the tourists in our survey who said they were visiting the reef to “see it before it is gone” nevertheless had low levels of concern about their own impacts on the region.

Where to from here?

We undertook our survey in 2015, before this year’s bleaching event, described as the most severe in the GBR’s history.

This raises another question: is there a threshold beyond which the GBR is seen as “too far gone” to visit? If so, might future more frequent or severe bleaching episodes take us past that threshold?

As the most important source of information for tourists visiting the GBR, the media in particular need to acknowledge their own important role in informing the public. Media outlets need to portray the reef’s current status as accurately as possible. The media’s power and influence also afford them a great opportunity to help advocate for the GBR’s protection.

Educating tourists about the threats facing the GBR is an important way forward, particularly as our research identified major gaps in tourists’ understanding of the specific threats facing the GBR and the impacts of their own behaviour. Many survey respondents, for instance, expressed low levels of concern about agricultural runoff, despite this being one of the biggest threats facing the GBR.

Of course, tourism is just one element in a complex web of issues that affect the GBR and needs to be part of a wider consideration of the reef’s future.

The only thing that is certain is that more needs to be done to ensure this critical ecosystem can survive, so that tourists who think this is the last chance to see it can hopefully be proved wrong.

The Conversation

Annah Piggott-McKellar, PhD Candidate, The University of Queensland and Karen Elizabeth McNamara, Senior lecturer, The University of Queensland

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

Red Centre Holiday 2016: Day 4 – Woomera, South Australia to Marla, South Australia


It was a much later start in the day for me today, departing Woomera at about 7.15am. Being as ill as I was with the flu, I felt I could use the sleep-in. Once I was on my way, it was just off to Pimba for a quick fuel pit stop – Pimba is only a very short distance up the road and took only a matter of minutes to get there. This also marked the beginning of the more expensive fuel prices, with ULP coming in at $1.60 a litre at Pimba. It would be $2.02 at Kings Canyon Resort.

ABOVE & BELOW: Wildflowers Along the Stuart Highway

Once on the road proper, I again searched for a number of geocaches along the way. These helped to highlight the land that I was travelling through and allowed for regular leg stretching, which always helps when on the road for long periods of time. Another thing that helped to break up the day were the wildflowers, with a number of short breaks taken throughout the journey to take in the spectacle at close quarters. The wildflowers were really something that struck me during my holiday travels. They were really something throughout central Australia.

ABOVE & BELOW: Wildflowers Along the Stuart Highway

Coober Pedy was my first major stop as I headed north towards Marla and as I drew closer to the Opal town I visited two monuments along the Stuart Highway – a monument marking the discovery of opal at Coober Pedy and another the explorer John MacDouall Stuart.

ABOVE: The John MacDouall Stuart Monument Near Coober Pedy

Coober Pedy has never really appealed to me and once again I found myself wanting to get my business in the town settled and to be on my way again. There was a fuel stop and some grocery shopping in the local IGA, knowing that prices would become much higher the further inland I headed. The prices in the shop at Kings Canyon Resort took my breath away, and I for one believed it was little more than price gouging given that there was nowhere else to go. But Kings Canyon was still several days away and so that shock was still to come.

ABOVE: Welcome to Coober Pedy

From Coober Pedy it was a pretty straight-forward run to Marla and my first night in the tent at Marla Traveller’s Rest. It was quite a cold night and with the flu I wasn’t really looking forward to it. However, my car-based camping set-up allows me a very comfortable and warm sleeping environment, so there were no real dramas. It was however a very cold night when out of the sleeping bag and out from under the covers. It was probably close to zero.

The distance travelled on this day was 599 km – giving me a total of 2369 km for the whole trip to this point.

Once again it was the usual ‘house keeping’ before bed – updating the daily journal, reviewing the holiday budget, checking in on social media, and editing and uploading photos. Then it was off to bed for an early start the next morning, with the excitement mounting, as I would arrive in Yulara the next day and be within sight of Uluru – the main goal of my holiday.

View the Photos at:
https://flic.kr/s/aHskFFWHSE

Visit the Red Centre Holiday 2016 web page at:
http://kevinswilderness.com/NT/redcentre2016.html

Red Centre Holiday 2016: Day 3 – Broken Hill, New South Wales to Woomera, South Australia


The day once again started early for me, as I hit the road determined to make Woomera in good time – especially given that I intended to do quite a bit of geocaching along the way again. In fact, on this day I found upwards of a dozen caches as I travelled along. One of the reasons I enjoy geocaching (and believe me it isn’t for the goodies you find in the caches, as most is little more than junk) are the places it takes you to. Geocaching showed me some interesting sites as I travelled along, what is really quite a large and remote part of the country. It really helped to break up some of those vast distances I was travelling.

ABOVE: Arriving in South Australia  BELOW: Old Water Tower

ABOVE: Poor ‘Old Ted’  BELOW: Olary Railway Station

Other than the geocaching locations, one of the first stops of the day was at Cockburn, which marked the New South Wales – South Australian border. It was quite cold there, as it was for most of the journey across the southern stretch of Australia that I travelled on my holiday. But it was Olary that really caught my attention – a lovely old ‘bush’ type of town, seemingly lost in time. I loved the place, not that I saw a sole during the whole time I wandered about there – but to be fair it was cold and early.

ABOVE & BELOW: Morris Commercial at Olary

There were two main stops for fuel throughout the day. One at Yunta and one at Port Augusta – and these really were just quick pit stops to refuel. I then quickly moved on to Pimba and Woomera, staying the night in another cabin as I was still quite sick with the flu. This time I stayed at Woomera Traveller’s Village.

On this third day I travelled 600 km – giving me a total of 1769 km for the whole trip so far.

ABOVE: Concret Dice Near Yunta

Once again it was the usual ‘house keeping’ before bed – updating the daily journal, reviewing the holiday budget, checking in on social media, and editing and uploading photos. Then it was off to bed for an early start the next morning.

View the Photos at:
https://flic.kr/s/aHskH4YGLw

Visit the Red Centre Holiday 2016 web page at:
http://kevinswilderness.com/NT/redcentre2016.html

Our planet is heating – the empirical evidence


Mike Sandiford, University of Melbourne

In an entertaining and somewhat chaotic episode of ABC’s Q&A (Monday 15th August) pitting science superstar Brian Cox against climate contrarian and global conspiracy theorist and now senator Malcolm Roberts, the question of cause and effect and empirical data was raised repeatedly in regard to climate change.

Watching I pondered the question – what would I need to change my mind? After all, I should dearly love to be convinced that climate was not changing, or if it were, it were not due to human emissions of CO2 and other greenhouse gases. That would make things just so much easier, all round.

So what would make me change my mind?

There are two elements to this question. The first is the observational basis, and the question of empirical data, of a changing climate. The second relates to cause and effect, and the question of the greenhouse effect.

On the second, I will only add that the history of our planet is not easily reconciled without recourse to a strong greenhouse effect. If you have any doubt then you simply need to read my former colleague Ian Plimer.
As I have pointed out before, in his 2001 award-winning book “A Short History of Planet Earth”, Ian has numerous references to the greenhouse effect especially in relation to what all young geologists learn as the faint young sun paradox:

“The early sun had a luminosity of some 30 per cent less than now and, over time, luminosity has increased in a steady state.”

“The low luminosity of the early sun was such that the Earth’s average surface temperature would have been below 0C from 4500 to 2000 million years ago. But there is evidence of running water and oceans as far back as 3800 million years ago.”

The question is, what kept the early Earth from freezing over?

Plimer goes on to explain: “This paradox is solved if the Earth had an enhanced greenhouse with an atmosphere of a lot of carbon dioxide and methane.”

With Ian Plimer often touted as one of the grand priests of climate contrarians, I doubt that Malcolm Roberts would consider him part of a cabal of global climate change conspiracists, though that would be ironic.

As a geologist, I need to be able to reconcile the geological record of a watery planet from time immemorial with the faint young sun hypothesis. And, as Ian points out, with nothing else on the menu, the greenhouse effect is all we have.

If the menu changes, then I will reconsider.

How about the empirical data?

Along with Brian Cox, I find it implausible that an organisation like NASA, with a record of putting a man on the moon, could or would fabricate data to the extent Malcolm Roberts insinuates. It sounds such palpable nonsense, it is something you might expect from an anti-vaxer.

However, a clear message from the Q&A episode is there is no way to convince Malcolm Roberts that the meteorological temperature data has not been manipulated to achieve a predetermined outcome. So he simply is not going to accept those data as being empirical.

However,
the relevant data does not just include the records taken by meteorological authorities. It also includes the the record preserved beneath our feet in the temperature logs from many thousands of boreholes across all inhabited continents. And the importance of those logs is that they are reproducible. In fact Malcolm can go out an re-measure them himself, if he needs convincing they are “empirical”.

The idea that the subsurface is an effective palaeo-thermometer is a simple one that we use in our every day life, or used to at least prior to refrigeration, as it provides the logic for the cellar.

When we perturb the temperature at the surface of the earth, for example as the air temperature rises during the day, it sends a heat pulse downwards into the earth. The distance the pulse travels is related to its duration. As the day turns to night and the surface cools, a cooling pulse will follow, lagging behind, but eventually cancelling, the daily heating. The diurnal surface temperature perturbations produce a wave like train of heating and cooling that can be felt with diminishing amplitude down to a skin depth less than a metre beneath the surface before all information is cancelled out, and the extremes of both day and night are lost.

Surface temperatures also change on a seasonal basis from summer to winter and back again, and those temperatures propagate even further to depths of around 10 metres before completely cancelling [1].

On even longer cycles the temperature anomalies propagate much further,
and may reach down to a kilometre or more. For example, we know that over the last million years the temperature on the earth has cycled in and out of numerous ice ages, with a period of about 100,000 years. Cycles of that duration can propagate more than one kilometre into the earth, as we see in deep boreholes, such as the Blanche borehole near the giant Olympic Dam mine in South Australia. From our analysis of the Blanche temperature logs we infer a surface temperature amplitude of around 8°C over the glacial cycle.

So what do we see in the depth range of 20-100 metres that is sensitive to the last 100 years, and most relevant to the question of changing climate?

The image below shows the temperature log from a borehole that we purpose drilled in Gippsland as part of AuScope AGOS program.

Temperature log in the upper 70 metres of the Tynong AGOS borehole drilled and cored to a depth of 500 metres. The temperature logs shown here were obtained by Kate Gordon, as a student at the University of Melbourne.

The temperature profile shows various stages. Above the water table at about 15 metres depth, due to infiltration of groundwater in the vadose zone, the temperatures in the borehole rapidly equilibrate to seasonal surface temperature changes. In the winter, when this temperature log was obtained, the temperatures in this shallow zone trend towards the ambient temperature around 12°C. In summer, they rise to over 20°C. Beneath the vadose zone, the temperature in the borehole responds to the conduction of heat influenced by two dominant factors, the changing surface temperature on time-scales of decades to many hundred of years, and the heat flow from the deeper hot interior of the earth. During a rapid surface warming cycle lasting more than several decades the normal temperature gradient in which temperatures increase with depth can be reversed, so that we get a characteristic rollover (with a minimum here seen at about 30 metres depth).

Inversion of the Tynong temperature log for surface temperature change over the last 700 years, with uncertainties at the 95% confidence interval. The inversion, which is based on Fourier’s law of heat conduction, shows that we can be confident that the Tynong AGOS borehole temperature record is responding to a long-term heating cycle of 0.3-1.3°C over the last century at the 95% confidence level. The inversion shown here was performed by Kate Gordon.

In geophysics we use the techniques of inversion to identify causative signals, and their uncertainties, in records such as the Tynong borehole log, as well as in the estimation of the value of buried ore bodies and hydrocarbon resources. As shown in the second image, the inversion of the Tynong temperature log for surface temperature change over the last 700 years, with uncertainties at the 95% confidence interval, is compelling. Not surprisingly as we go back in time the uncertainties become larger. However, the inversion, which is based on Fourier’s law of heat conduction, shows that we can be confident that the Tynong AGOS borehole temperature record is responding to a long-term heating cycle of 0.3-1.3°C over the last century at the 95% confidence level.

If there were just one borehole that showed this record, it would not mean much. However the characteristic shallow rollover is present in all the boreholes we have explored, and has been reported in many thousands of boreholes from all around the world.

The only way we know to sensibly interpret such empirical evidence is that ground beneath our feet, down to a depth of around 50 metres or so is now heating from above. The physics that explains these observations dates back to Joseph Fourier, over 200 years ago, so its not exactly new or even contentious. In effect the solid earth below is now absorbing heat from the atmosphere above, counter to the normal process of losing heat to it. However, if Malcolm can bring to the table an alternative physics to explain these observations, while not falling foul of all the other empirical observations that Fourier’s law of heat conduction admits, then I am happy to consider, and put it to the test. (I suspect Brian Cox would be too, since all good physicists would relish the discovery of a new law of such importance as Fourier’s law).

Perhaps the hyper-skeptical Malcolm thinks that somehow the global cabal of climate scientists has got into all these thousands of boreholes with an electrical heater to propagate the heat signal that artificially simulates surface heating. More fool me.

But, if he does, then I am perfectly happy to arrange to drill a new borehole and, along with him, measure the temperature profile, making sure we don’t let those pesky climate scientists get at the hole with their heating coils before we have done so.

And I’ll bet him we can reproduce the signal from Tynong shown above.

But I’ll only do it on the condition that Malcolm agrees, that when we do (reproduce the signal), he will publicly acknowledge the empirical evidence of a warming world entirely consistent with NASA’s surface temperature record.

Malcolm, are you on? Will you take on my bet, and use the Earth’s crust as the arbiter? Perhaps Brian will stream live to the BBC?

The Conversation

Mike Sandiford, Chair of Geology & Redmond Barry Distinguished Professor, University of Melbourne

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