Africa is splitting in two – here is why



File 20180329 189813 qaz48d.png?ixlib=rb 1.1

Google Earth. Data SIO, NOAA, US Navy, NGA, GEBCO

Lucia Perez Diaz, Royal Holloway

A large crack, stretching several kilometres, made a sudden appearance recently in south-western Kenya. The tear, which continues to grow, caused part of the Nairobi-Narok highway to collapse. Initially, the appearance of the crack was linked to tectonic activity along the East African Rift. But although geologists now think that this feature is most likely an erosional gully, questions remain as to why it has formed in the location that it did and whether its appearance is at all connected to the ongoing East African Rift. For example, the crack could be the result of the erosion of soft soils infilling an old rift-related fault.

The Earth is an ever-changing planet, even though in some respects change might be almost unnoticeable to us. Plate tectonics is a good example of this. But every now and again something dramatic happens and leads to renewed questions about the African continent splitting in two.

The Earth’s lithosphere (formed by the crust and the upper part of the mantle) is broken up into a number of tectonic plates. These plates are not static, but move relative to each other at varying speeds, “gliding” over a viscous asthenosphere. Exactly what mechanism or mechanisms are behind their movement is still debated, but are likely to include convection currents within the asthenosphere and the forces generated at the boundaries between plates.

These forces do not simply move the plates around, they can also cause plates to rupture, forming a rift and potentially leading to the creation of new plate boundaries. The East African Rift system is an example of where this is currently happening.

The East African Rift Valley stretches over 3,000km from the Gulf of Aden in the north towards Zimbabwe in the south, splitting the African plate into two unequal parts: the Somali and Nubian plates. Activity along the eastern branch of the rift valley, running along Ethiopia, Kenya and Tanzania, became evident when the large crack suddenly appeared in south-western Kenya.

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Why does rifting happen?

When the lithosphere is subject to a horizontal extensional force it will stretch, becoming thinner. Eventually, it will rupture, leading to the formation of a rift valley.

Great Rift Valley, Tanzania.
Shutterstock

This process is accompanied by surface manifestations along the rift valley in the form of volcanism and seismic activity. Rifts are the initial stage of a continental break-up and, if successful, can lead to the formation of a new ocean basin. An example of a place on Earth where this has happened is the South Atlantic ocean, which resulted from the break up of South America and Africa around 138m years ago – ever noticed how their coastlines match like pieces of the same puzzle?.

Maps made by Snider-Pellegrini in 1858 showing his idea of how the American and African continents may once have fitted together.
https://en.wikipedia.org/wiki/Antonio_Snider-Pellegrini#/media/File:Antonio_Snider-Pellegrini_Opening_of_the_Atlantic.jpg

Continental rifting requires the existence of extensional forces great enough to break the lithosphere. The East African Rift is described as an active type of rift, in which the source of these stresses lies in the circulation of the underlying mantle. Beneath this rift, the rise of a large mantle plume is doming the lithosphere upwards, causing it to weaken as a result of the increase in temperature, undergo stretching and breaking by faulting.

Mantle plume (left).
Reprinted from Tetrophysics, Vol 513, Oliver Mearle, ‘A simple continental rift classification’ Copyright (2011), with permission from Elsevier.

Evidence for the existence of this hotter-than-normal mantle plume has been found in geophysical data and is often referred to as the “African Superswell”. This superplume is not only a widely-accepted source of the pull-apart forces that are resulting in the formation of the rift valley but has also been used to explain the anomalously high topography of the Southern and Eastern African Plateaus.

Breaking up isn’t easy

Rifts exhibit a very distinctive topography, characterised by a series of fault-bounded depressions surrounded by higher terrain. In the East African system, a series of aligned rift valleys separated from each other by large bounding faults can be clearly seen from space.

Topography of the Rift Valley.
James Wood and Alex Guth, Michigan Technological University. Basemap: Space Shuttle radar topography image by NASA

Not all of these fractures formed at the same time, but followed a sequence starting in the Afar region in northern Ethiopia at around 30m years ago and propagating southwards towards Zimbabwe at a mean rate of between 2.5-5cm a year.

Although most of the time rifting is unnoticeable to us, the formation of new faults, fissures and cracks or renewed movement along old faults as the Nubian and Somali plates continue moving apart can result in earthquakes.

However, in East Africa most of this seismicity is spread over a wide zone across the rift valley and is of relatively small magnitude. Volcanism running alongside is a further surface manifestation of the ongoing process of continental break up and the proximity of the hot molten asthenosphere to the surface.

A timeline in action

The East African Rift is unique in that it allows us to observe different stages of rifting along its length. To the south, where the rift is young, extension rates are low and faulting occurs over a wide area. Volcanism and seismicity are limited.

Towards the Afar region, however, the entire rift valley floor is covered with volcanic rocks. This suggests that, in this area, the lithosphere has thinned almost to the point of complete break up. When this happens, a new ocean will begin forming by the solidification of magma in the space created by the broken-up plates. Eventually, over a period of tens of millions of years, seafloor spreading will progress along the entire length of the rift. The ocean will flood in and, as a result, the African continent will become smaller and there will be a large island in the Indian Ocean composed of parts of Ethiopia and Somalia, including the Horn of Africa.

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Dramatic events, such as sudden motorway-splitting faults can give continental rifting a sense of urgency. However, rifting is a very slow process that, most of the time, goes about splitting Africa without anybody even noticing.

The ConversationThis article was updated and the headline changed on April 7 to reflect ongoing discussion by geologists about the cause of the large crack that appeared on the East Africa Rift and whether its location is related to the African continent split.

Lucia Perez Diaz, Postdoctoral Researcher, Fault Dynamics Research Group, Royal Holloway

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

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Not so fast: why the electric vehicle revolution will bring problems of its own



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Electric cars are taking over – but they really as green as they look?
Jack Amick / flickr, CC BY-NC

Martin Brueckner, Murdoch University

After years of being derided as a joke by car manufacturers and the public, interest in electric vehicles has increased sharply as governments around the world move to ban petrol and diesel cars.

We have seen a tremendous rise in availability, especially at the premium end of the market, where Tesla is giving established brands a run for their money. Electric cars are likely to penetrate the rest of the market quickly too. Prices should be on par with conventional cars by 2025.

Electric cars are praised as the answer to questions of green and clean mobility. But the overall sustainability of electric vehicles is far from clear. On closer examination, our entire transport paradigm may need to be rethought.




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Compared with combustion engines, electric transport has obvious advantages for emissions and human health. Transport is responsible for around 23% of energy-related carbon dioxide emissions globally. This is expected to double by 2050.

Motor vehicles also put a burden on society, especially in urban environments where they are chiefly responsible for noise and air pollution. Avoiding these issues is why electric vehicles are considered a key technology in cleaning up the transport sector. However, electric cars come with problems of their own.

Dirt in the supply chain

For one, electric vehicles have a concerning supply chain. Cobalt, a key component of the lithium-ion batteries in electric cars, is linked to reports of child labour. The nickel used in those same batteries is toxic to extract from the ground. And there are environmental concerns and land use conflicts connected with lithium mining in countries like Tibet and Bolivia.

The elements used in battery production are finite and in limited supply. This makes it impossible to electrify all of the world’s transport with current battery technology. Meanwhile, there is still no environmentally safe way of recycling lithium-ion batteries.

While electric cars produce no exhaust, there is concern about fine particle emissions. Electric cars are often heavier than conventional cars, and heavier vehicles are often accompanied by higher levels of non-exhaust emissions. The large torque of electric vehicles further adds to the fine dust problem, as it causes greater tyre wear and dispersion of dust particles.

Different motor, same problem

Electric vehicles share many other issues with conventional cars too. Both require roads, parking areas and other infrastructure, which is especially a problem in cities. Roads divide communities and make access to essential services difficult for those without cars.

A shift in people’s reliance on combustion cars to electric cars also does little to address sedentary urban lifestyles, as it perpetuates our lack of physical activity.

Other problems relate to congestion. In Australia, the avoidable social cost of traffic congestion in 2015 was estimated at A$16.5 billion. This is expected to increase by 2% every year until 2030. Given trends in population growth and urbanisation globally and in Australia, electric cars – despite obvious advantages over fossil fuels – are unlikely to solve urban mobility and infrastructure-related problems.

Technology or regulation may solve these technical and environmental headaches. Improvements in recycling, innovation, and the greening of battery factories can go a long way towards reducing the impacts of battery production. Certification schemes, such as the one proposed in Sweden, could help deliver low-impact battery value chains and avoid conflict minerals and human rights violations in the industry.

A new transport paradigm

Yet, while climate change concerns alone seem to warrant a speedy transition towards electric mobility, it may prove to be merely a transition technology. Electric cars will do little for urban mobility and liveability in the years to come. Established car makers such as Porsche are working on new modes of transportation, especially for congested and growing markets such as China.

Nevertheless, their vision is still one of personal vehicles – relying on electric cars coupled with smart traffic guidance systems to avoid urban road congestion. Instead of having fewer cars, as called for by transport experts, car makers continue to promote individualised transport, albeit a greener version.

With a growing population, a paradigm shift in transport may be needed – one that looks to urban design to solve transportation problems.

In Copenhagen, for example, bikes now outnumber cars in the city’s centre, which is primed to be car-free within the next ten years. Many other cities, including Oslo in Norway and Chengdu in China, are also on their way to being free of cars.

Experts are already devising new ways to design cities. They combine efficient public transport, as found in Curitiba, Brazil, with principles of walkability, as seen in Vauben, Germany. They feature mixed-use, mixed-income and transit-oriented developments, as seen in places like Fruitvale Village in Oakland, California.




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Designing suburbs to cut car use closes gaps in health and wealth


These developments don’t just address transport-related environmental problems. They enhance liveability by reclaiming urban space for green developments. They reduce the cost of living by cutting commuting cost and time. They deliver health benefits, thanks to reduced pollution and more active lifestyles. They improve social cohesion, by fostering human interaction in urban streetscapes, and help to reduce crime. And of course, they improve economic performance by reducing the loss of productivity caused by congestion.

The ConversationElectric cars are a quick-to-deploy technology fix that helps tackle climate change and improve urban air quality – at least to a point. But the sustainability endgame is to eliminate many of our daily travel needs altogether through smart design, while improving the parts of our lives we lost sight of during our decades-long dependence on cars.

Martin Brueckner, Senior Lecturer in Sustainability, Murdoch University

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

Six ways to improve water quality in New Zealand’s lakes and rivers


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Lake Tarawera, seen from its outlet, has excellent but declining water quality.
Troy Baisden, CC BY-SA

Troy Baisden, University of Waikato

Two years ago, New Zealanders were shocked when contaminated drinking water sickened more than 5,000 people in the small town of Havelock North, with a population of 14,000. A government inquiry found that sheep faeces were the likely source of bacterial pathogens, which entered an aquifer when heavy rain flooded surrounding farmland.

A second phase of the inquiry identified six principles of international drinking water security that had been bypassed. Had they been followed, the drinking water contamination would have been prevented or greatly reduced.

Here, I ask if the approach recommended by the Havelock North inquiry to prevent drinking water contamination can be extended to reduce the impacts of nutrient contamination of freshwater ecosystems.




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We all live downstream – it’s time to restore our freshwater ecosystems


Freshwater degraded and in decline

Most measures of the ecological health and recreational value of New Zealand’s lowland rivers and lakes have been rated as degraded and still declining. Intensive agriculture often cops much of the blame, but primary industry exports remain the heart of New Zealand’s economy.

The challenge posed by this trade-off between the economy and the environment has been described as both enormous, and complex. Yet it is a challenge that New Zealand’s government aims to tackle, and continues to rate as a top public concern.

An important lesson from the Havelock North inquiry is that sometimes there is no recipe – no easy list of steps or rules we can take to work through a problem. Following existing rules resulted in a public health disaster. Instead, practitioners need to follow principles, and be mindful that rules can have exceptions.

For freshwater, New Zealand has a similar problem with a lack of clear actionable rules, and I’ve mapped a direct link between the six principles of drinking water security and corresponding principles for managing nutrient impacts in freshwater.

Six principles for freshwater

Of the six principles of drinking water safety, the first is perhaps the most obvious: drinking water safety deserves a “high standard of care”. Similarly, freshwater nutrient impact management should reflect a duty of care that mirrors the scale of impacts. Our most pristine freshwater, like Lake Taupo, and water on the verge of tipping into nearly irreversible degradation, deserve the greatest effort and care.

Second, drinking water safety follows a clear logic from the starting point: “protecting the integrity of source water is paramount”. For nutrient impact management in freshwater, we must reverse this and focus on a more forensic analysis along flowpaths to the source of excess nutrients entering water. Our current approach of using estimates of sources is not convincing when tracers could point to sources in the same way DNA can help identify who was at a crime scene. We must link impacts to sources.

Third, drinking water safety demands “multiple barriers to contamination”. For freshwater, we’re better off taking a similar but different approach – maximising sequential reductions of contamination. There are at least three main opportunities, including farm management, improving drains and riparian vegetation, and enhancing and restoring wetlands. If each is 50% effective at reducing contaminants reaching waterways, the three are as good as a single barrier that reduces contamination by 90%. The 50% reductions are likely to be much more achievable and cost effective.

Managing hot spots and hot moments

The fourth principle of drinking water safety was perhaps the most dramatic failure in the Havelock North drinking water crisis: “change precedes contamination”. Despite a storm and flood reaching areas of known risk for contaminating the water supply, there were no steps in place to detect changing conditions that breached the water supply’s classification as “secure” and therefore safe.

A similar, but inverted principle can keep nutrients on farm, where we want them, and keep them out of our water. Almost all processes that lead to nutrient excess and mobilisation, as well as its subsequent removal, occur in hot spots and hot moments.

This concept means that when we look, we find that roughly 90% of excess nutrients come from less than 10% of the land area, or events that represent less than 10% of time. We can identify these hot spots and hot moments, and classify them into a system of control points that are managed to limit nutrient contamination of freshwater.

Lake Taupo, New Zealand’s largest lake, has a nitrogen cap and trade programme in place, which allocates farmers individual nitrogen discharge allowances.
from Shutterstock, CC BY-SA

Establishing clear ownership

A fifth principle for drinking water seems obvious: “suppliers must own the safety of drinking water”. Clear ownership results in clear responsibility.

Two world-leading cap-and-trade schemes created clear ownership of nutrient contaminants reaching iconic water bodies. One is fully in place in the Lake Taupo catchment, and another is still under appeal in the Lake Rotorua catchment.

These schemes involved government investment of between NZ$70 million and NZ$80 million to “buy out” a proportion of nutrients reaching the lakes. This cost seems unworkable across the entire nation. Will farmers or taxpayers own this cost, or is there any way to pass it on to investors in new, higher-value land use that reduces nutrient loss to freshwater? A successful example of shifting to higher value has been conversions from sheep and beef farming to vineyards.

As yet, the ownership of water has made headlines, but remains largely unclear outside Taupo and Rotorua when it comes to nutrient contaminants. Consideration of taxing the use of our best water could be much more sensible with a clearer framework of ownership for both water and the impacts of contaminants.

The final principle of drinking water safety is to “apply preventative risk management”. This is a scaled approach that involves thinking ahead of problems to assess risks that can be mitigated at each barrier to contamination.

For nutrient management in water, a principled approach has to start with the basic fact that water flows and must be managed within catchments. From this standpoint, New Zealand has a good case for leading internationally, because regional councils govern the environment based on catchment boundaries.

Within catchments we still have a great deal of work to do. This involves understanding how lag effects can lead to a legacy of excess nutrients. We need to manage whole catchments by understanding, monitoring and managing current and future impacts in the entire interconnected system.

The ConversationIf we can focus on these principles, government, industry, researchers, NGOs and the concerned public can build understanding and consensus together, enabling progress towards halting and reversing the declining health and quality of our rivers and lakes.

Troy Baisden, Professor and Chair in Lake and Freshwater Sciences, University of Waikato

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

How the 2016 bleaching altered the shape of the northern Great Barrier Reef



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Staghorn and tabular corals suffered mass die-offs, robbing many individual reefs of their characteristic shapes.
ARC Centre of Excellence for Coral Reef Studies/ Mia Hoogenboom

Selina Ward, The University of Queensland

In 2016 the Great Barrier Reef suffered unprecedented mass coral bleaching – part of a global bleaching event that dwarfed its predecessors in 1998 and 2002. This was followed by another mass bleaching the following year.

This was the first case of back-to-back mass bleaching events on the reef. The result was a 30% loss of corals in 2016, a further 20% loss in 2017, and big changes in community structure. New research published in Nature today now reveals the damage that these losses caused to the wider ecosystem functioning of the Great Barrier Reef.

Fast-growing staghorn and tabular corals suffered a rapid, catastrophic die-off, changing the three-dimensional character of many individual reefs. In areas subject to the most sustained high temperatures, some corals died without even bleaching – the first time that such rapid coral death has been documented on such a wide scale.




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The research team, led by Terry Hughes of James Cook University, carried out extensive surveys during the two bleaching events, at a range of scales.

First, aerial surveys from planes generated thousands of videos of the reef. The data from these videos were then verified by teams of divers in the water using traditional survey methods.

Finally, teams of divers took samples of corals and investigated their physiology in the laboratory. This included counting the density of the microalgae that live within the coral cells and provide most of the energy for the corals.

The latest paper follows on from earlier research which documented the 81% of reefs that bleached in the northern sector of the Great Barrier Reef, 33% in the central section, and 1% in the southern sector, and compared this event with previous bleaching events. Another previous paper documented the reduction in time between bleaching events since the 1980s, down to the current interval of one every six years.

Different colour morphs of Acropora millepora, each exhibiting a bleaching response during mass coral bleaching event.
ARC Centre of Excellence for Coral Reef StudiesStudies/ Gergely Torda

Although reef scientists have been predicting the increased frequency and severity of bleaching events for two decades, this paper has some surprising and alarming results. Bleaching events occur when the temperature rises above the average summer maximum for a sufficient period. We measure this accumulated heat stress in “degree heating weeks” (DHW) – the number of degrees above the average summer maximum, multiplied by the number of weeks. Generally, the higher the DHW, the higher the expected coral death.

The US National Oceanic and Atmospheric Administration has suggested that bleaching generally starts at 4 DHW, and death at around 8 DHW. Modelling of the expected results of future bleaching events has been based on these estimates, often with the expectation the thresholds will become higher over time as corals adapt to changing conditions.

In the 2016 event, however, bleaching began at 2 DHW and corals began dying at 3 DHW. Then, as the sustained high temperatures continued, coral death accelerated rapidly, reaching more than 50% mortality at only 4-5 DHW.

Many corals also died very rapidly, without appearing to bleach beforehand. This suggests that these corals essentially shut down due to the heat. This is the first record of such rapid death occurring at this scale.

This study shows clearly that the structure of coral communities in the northern sector of the reef has changed dramatically, with a predominant loss of branching corals. The post-bleaching reef has a higher proportion of massive growth forms which, with no gaps between branches, provide fewer places for fish and invertebrates to hide. This loss of hiding places is one of the reasons for the reduction of fish populations following severe bleaching events.




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The world’s coral reefs are in trouble, but don’t give up on them yet


The International Union for Conservation of Nature (IUCN), which produces the Red List of threatened species, recently extended this concept to ecosystems that are threatened with collapse. This is difficult to implement, but this new research provides the initial and post-event data, leaves us with no doubt about the driver of the change, and suggests threshold levels of DHWs. These cover the requirements for such a listing.

Predictions of recovery times following these bleaching events are difficult as many corals that survived are weakened, so mortality continues. Replacement of lost corals through recruitment relies on healthy coral larvae arriving and finding suitable settlement substrate. Corals that have experienced these warm events are often slow to recover enough to reproduce normally so larvae may need to travel from distant healthy reefs.

Although this paper brings us devastating news of coral death at relatively low levels of heat stress, it is important to recognise that we still have plenty of good coral cover remaining on the Great Barrier Reef, particularly in the southern and central sectors. We can save this reef, but the time to act is now.

This is not just for the sake of our precious Great Barrier Reef, but for the people who live close to reefs around the world that are at risk from climate change. Millions rely on reefs for protection of their nations from oceanic swells, for food and for other ecosystem services.

The ConversationThis research leaves no doubt that we must reduce global emissions dramatically and swiftly if we are save these vital ecosystems. We also need to invest in looking after reefs at a local level to increase their chances of surviving the challenges of climate change. This means adequately funding improvements to water quality and protecting as many areas as possible.

Selina Ward, Senior Lecturer, School of Biological Sciences, The University of Queensland

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

Contrary to common belief, some forests get more fire-resistant with age


Philip Zylstra, University of Wollongong

An out-of-season bushfire raged through Sydney’s southwest at the weekend, burning more than 2,400 hectares and threatening homes.

As the fire season extends and heatwaves become more frequent, it’s vital to preserve our natural protections. My research, recently released in the journal Austral Ecology, contradict one of the central assumptions in Australian fire management – that forest accumulate fuel over time and become increasingly flammable.




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I looked at every fire in every forest in the Australian Alps National Parks and found that mature forests are dramatically less likely to burn. Perhaps surprisingly, once a forest is several decades old it becomes one of our best defences against large bushfires.

The English approach

Within decades of the first graziers taking land in the Australian Alps, observers noticed that English-style management had unintended consequences for an Australian landscape.

In the British Isles, grazing rangelands had been created in the moors by regular burning over thousands of years, and this approach was imported wholesale to Australia’s mountains.

By 1893, however, the botanist Richard Helms had observed that as little as a year after fires were introduced to clear the land, “the scrub and underwood spring up more densely than ever”.

It’s true that, as in the rest of the country, many shrubs in the Alps are germinated by fire. However, the Alps also lie in a climatic zone where many trees are easily killed by fire. As a result, fire produces dense regrowth, and in the worst cases, removes the forest canopy that is essential to maintaining a still, moist micro-climate. Fires burning in this regrowth have abundant dry fuel, and they are exposed to the full strength of the wind.




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Theoretically, that should make regrowth more flammable than old growth, but it is at odds with the widespread assumption that fuels accumulate over time to make old forests the most flammable. Which is the case then? Are old forests more or less flammable than regrowth?

36 million case studies

Looking back over 58 years of mapped fires in the 12 national parks and reserves that make up the Australian Alps National Parks, I asked a simple question: when a wildfire burnt the mountains, did it favour one age of forest over another? If there were equal amounts of forest burnt say, five years, 10 years or 50 years ago, did fires on average burn more in one of those ages than another?

It’s not an entirely new question; people have often studied what happened when a fire crossed into recently burnt areas.

However, instead of just looking at part of a fire, I looked at every hectare it had burnt as separate case study. Instead of only looking at recent fires, I looked at every recorded fire in every forest across the Australian Alps National Parks. Instead of a handful of case studies, I now had 36 million of them.

Consistent with all of the other studies, I found that forests became more flammable in the years after they were burnt; but this is where the similarity ended. Rather than stop there as the other studies have done, I pushed past this line and found something striking. Regardless of which forest I examined, it became dramatically less likely to burn when it matured after 14 to 28 years.

Alpine Ash forests become increasingly flammable until the trees are tall enough to avoid ignition, and the shrubs thin out.
Phil Zylstra, Author provided

The most marked response of these was in the tall, wet Ash forests. These have been unlikely to burn for about three years after a fire, but then the regrowth comes in. Until these trees are about 21 years old, Ash forests are one of the most flammable parts of the mountains, but after this, their flammability drops markedly. When our old Ash forest is burnt, it is condemned to two decades in which it is more than eight times as flammable.

https://cdn.knightlab.com/libs/juxtapose/latest/embed/index.html?uid=8818c198-4143-11e8-b263-0edaf8f81e27

The forests across the Alps have survived by constructing communities that keep fires small; but their defences are being broken down in the hotter, drier climate we are creating. Roughly the same area of the Victorian Alps was burnt by wildfire in the 10 years from 2003-2014 as had been burnt in the previous 50 years.




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To fight the catastrophic fires of the future, we need to look beyond prescribed burning


More fire means more flammable forests, which in turn mean more fire; it’s a positive feedback that can accelerate until fire-sensitive ecosystems such as the Ash collapse into permanently more flammable shrublands. Knowing this, however, gives us tools.

The ConversationOld forests are assets to be protected, and priority can be given to nursing older regrowth into its mature stages. It may be the eleventh hour, but we’re better placed now to stand with the forests and add what we can to their fight to survive climate change.

Philip Zylstra, Research Fellow, flammability and fire behaviour, University of Wollongong

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

What children can teach us about looking after the environment



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6-year-olds have the social skills to cooperatively overcome the competition of a resource dilemma.
from www.shutterstock.com

Rebecca Koomen, Max Planck Institute

United States President Donald Trump sparked outrage last year when he announced that the US would pull out of the Paris climate agreement. The decision frustrated world leaders because it undermined the process of global cooperation, setting a bad precedent for future agreements to unify countries in the effort to avoid climate disaster.

This is an example of a very common social dilemma, called a common-pool resource (CPR) dilemma. When a natural resource is open access, such as fish in a lake, everyone has to limit the amount they take individually in order to sustain the resource over the long term.

But if some people don’t cooperate, for example by overfishing or pulling out of a global climate agreement, they risk collapsing the resource for everyone else, leading others to follow suit.

Our research, published today in Nature Human Behaviour, found that some six-year-old children are capable of cooperating to sustain a CPR dilemma using strategies resembling those of the most successful real-world solutions by adults.

From tragedy to hope

Back in the 1960s, economists believed this type of environmental dilemma to be unsolvable, famously labelling these competitive traps as the tragedy of the commons.




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The tragedy of the over-surveyed commons


More recent work by Nobel laureate Elinor Ostrom tells us that we do actually have the social skills necessary to cooperate and avoid environmental tragedy, when we can communicate and come to fair agreements about how a resource should be divided.

If we fail to find cooperative solutions to these dilemmas, we risk facing disastrous environmental outcomes. Understanding our behaviour and the conditions that are most likely to lead to cooperation could better prepare us to create solutions in the future.

For this reason, myself and my colleague, Esther Herrmann, at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, recently set out to explore the roots of human behaviour in CPR dilemmas.

We looked at how children deal with such a dilemma in the laboratory in order to find out if these basic social skills are already present in developing children. Because children are not yet exposed to as much environmental information as adults, we asked: are children are able to spontaneously use these skills in a novel context to avoid resource collapse?

A magic water game

To test the social behaviour of pairs of six-year-olds in a CPR dilemma, we created an apparatus that mimicked a renewing, but collapsible common-pool resource, “magic water”. The water was slowly pumped from a clear container at the top of the apparatus into a clear cylinder, where it became accessible to the kids for the taking.

Each child and their partner had a clear box in front of them with a set of buoyant eggs inside. They used the magic water to float eggs to the top of the boxes and could then trade their raised eggs for candies at the end of the game. To collect magic water, children could turn an individual water tap on and off whenever they pleased throughout the game, which looked like this:

This image shows a pair of kids playing the common-pool magic water game. Each child could use the magic water to collect eggs they could exchange for candies, but if either one or both took too much water at any given time, they risked collapsing the resource. In order to get the most magic water possible, kids had to work together to sustain it, much like a real-world environmental dilemma.

There was a trick to it though: If either one or both children took too much water at any given time, they risked collapsing the resource which meant no one could get any more. To produce resource collapse, we put a bright red cork into the cylinder where children harvested their magic water. When this cork fell with the water level to a red threshold near the bottom of the cylinder, a magnet mechanism engaged, pulling out a plug at the bottom of the cylinder, dumping all the magic water into a bucket below, out of reach of the children.

Although kids were much more successful at sustaining the magic water when they had their own independent source – instead of a shared (open access) source – about 40% of pairs did find a way to sustain the magic water together. This means partners collapsed the water in the majority of trials, earning fewer candies because they succumbed to the competition of the game. As we know from research with adults in CPR dilemmas, success is far from guaranteed, owing to the competitive nature of this type of dilemma. But, the number of children who did manage to sustain the water shows these skills develop early. Our challenge will be to find ways of fostering these successful behaviours.

For the pairs who managed to avoid resource collapse, some social patterns emerged, and interestingly, these patterns resemble the successful strategies used by adults in real-world CPR dilemmas.

Children’s strategies resemble those of successful adults

One pattern to emerge was a series of verbal rules many of the kids spontaneously came up with and enforced on each other.

The most successful pairs were the ones that made inclusive rules that applied equally to both partners – like “now we both wait until the water rises and then we’ll both take a tiny bit!” – rather than the unilateral rules made up to benefit a dominant child, enforced at the expense of his or her partner.

Systems of rules generated, monitored and enforced by local communities are also some of the most effective strategies for adults in real-world and laboratory CPR dilemmas. For example, many lobster fishing communities in Maine have developed local systems of mapping fishing territories throughout their accessible waters which determine who is allowed to fish where, and when.




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Natural disasters test kids’ altruism


Another pattern evident in the successful sustainers’ behaviour was a tendency for partners to have similar or equal numbers of eggs at the end of the game. In fact, partners who collected more unequal amounts of eggs tended to collapse the magic water more quickly.

This is a pattern also seen in experiments with adults – we fare better when we can establish fair resource access and equitable risk management among stakeholders.

The ConversationOf course, determining what is fair in the global effort to curb the effects of climate change is more complex than a face-to-face game of common-pool magic water. But this work shows that the basic social building blocks needed to avert the tragedy of the commons develop and can be applied early.

Rebecca Koomen, Postdoc, Max Planck Institute

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