Ethiopia’s Lake Tana is losing the fight to water hyacinth



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The aquatic weed water hyacinth is causing major problems in Ethiopia’s Lake Tana.
Shutterstock

Solomon Kibret, University of California, Irvine

Lake Tana is the largest lake in Ethiopia. It holds 50% of the country’s fresh water. It is also the source of the Blue Nile, which contributes up to 60% of the Nile’s water. Not only is the lake important as a water source for over 123 million people in the Nile Basin, it is also a source of food in the form of fish. But weeds are threatening this life-giving resource.

The lake has been listed in the top 250 lake regions of Global Importance for Biodiversity. It has 28 species of fish, of which 21 are endemic. Commercially, the lake’s most important fishes include the large African barbs, Nile tilapia and African catfish. The annual commercial value of fish production at Lake Tana is about USD$1.1 million.

The potential fish production of the lake is estimated to be 13 000 tons yearly. But its current fish production is less than 1000 tons a year. Recent studies show a serious decline in fish stocks due to the spread of the aquatic weed water hyacinth around fish spawning grounds.

Water hyacinth, Eichhornia crassipes, is an exotic free-floating invasive plant that is native to South America. People who tend aquariums and gardens are believed to have spread the plant inadvertently across the Atlantic to Africa and Asia.

It restricts water flow, blocks sunlight from reaching native water plants and depletes the oxygen in the water – often choking aquatic animals like fish. It also has an economic impact by interfering with navigation, irrigation, power generation and fishery.

The infestation

The weed forms thick mats that cover the open water. Recent data show that Lake Tana is critically infested with water hyacinth and it’s putting the aquatic biodiversity at extreme risk.

In 2011, the Regional Environmental Bureau named water hyacinth as the most dangerous weed affecting Lake Tana. By then, about 20 000 hectares of the north-eastern shore of the lake was infested. In 2014, researchers from Ethiopia found out that about one-third of the lake’s shoreline, around 128km, was invaded by water hyacinth.

In just two years, the estimated coverage of the weed doubled from 20 000 to 40 000 hectares. The weed is now estimated to cover 50 000 hectares of the lake. To make matters worse, inflowing rivers carry heavy loads of soil and suspended sediment into the lake, which affects the water quality and creates favourable conditions for the spread of the weed.

The release of untreated waste water from industries around the lake adds to the deterioration of the lake ecosystem. As a consequence, the lake has lost 75% of its fish stock in recent years.

Farmers trying to remove water hyacinth from Lake Tana.
CGTN Africa

Control measures

A water hyacinth infestation is hard to get rid of. But there are three ways to do this: removal, chemical spraying (using herbicides) and biological control.

Removing the weed, either manually or using machines, could reduce coverage and slow its spread. But it’s expensive and takes time. Local authorities are mobilising an estimated 162 000 people to remove the weed by hand. This happens only when the lake shores are accessible and when farmers have time.

Lake Victoria, lying in Tanzania, Uganda and Kenya, offers lessons for dealing with the water hyacinth problem. An estimated 60 000 hectares is covered by the weed in Kenya alone. A weed harvesting machine can clear only 10 hectares a day, so it would take 6 000 days (more than 16 years) to remove the weed entirely. Methods like biological control have been shown to be more effective.

Herbicides have been widely used to reduce the spread of the weed, but they may harm the environment. They can kill native plants that are necessary for a healthy functioning of the lake’s ecosystem.

This control method is expensive for developing countries and requires highly skilled people. In Sudan, the costs of chemical treatment for water hyacinth control were estimated to be £1 million each year.

The best approach

Biological control has been widely used. It appears to be the most economical and effective approach to manage water hyacinth in the long term. It uses natural enemies, with little cost and usually no negative environmental impact. Two weevil – or beetle – species, Neochetina eichhorniae and Neochetina bruchi, have been widely used with success. They have shrunk the coverage of the weed and controlled its spread in 33 countries, including the United States, Uganda, Nigeria, Ghana, India and Australia. But this method takes years of work by the insect to clear the weed. For instance, the weevils took two years to control the weed at Lake Victoria in Uganda.

Neochetina weevils eat only water hyacinth. Studies show that these weevils rely on the water hyacinth’s root system for crucial stages of growing. They feed heavily on the plant tissue: larvae eat the inside of the plant and adults eat the outside. Feeding damage by both life stages inhibits the growth of the plant by slowing the flowering process.

Biological control using weevils has been successful in Lake Victoria. A recent study on the adaptability and efficacy of weevils for water hyacinth control in the Ethiopian Rift Valley showed promising results. Potential negative effects, however, should to be studied before realising the weevils to new environment. Once the weevils are released, there is no operational cost as they naturally reproduce and continue feeding until all the weed is cleared.

The ConversationResearchers are also looking at the potential of using weevils for water hyacinth control around Lake Tana. At least 2-3 million people living around the lake will be relying on the success of all these efforts.

Solomon Kibret, Postdoctoral researcher, University of California, Irvine

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

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Citizen scientist scuba divers shed light on the impact of warming oceans on marine life



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A volunteer diver surveys marine life at Lord Howe Island.
Rick Stuart-Smith/Reef Life Survey, Author provided

Madeleine De Gabriele, The Conversation

Rising ocean temperatures may result in worldwide change for shallow reef ecosystems, according to research published yesterday in Science Advances.

The study, based on thousands of surveys carried out by volunteer scuba divers, gives new insights into the relationship of fish numbers to water temperatures – suggesting that warmer oceans may drive fish to significantly expand their habitat, displacing other sea creatures.

Citizen science

The study draws from Reef Life Survey, a 10-year citizen science project that trains volunteer scuba divers to survey marine plants and animals. Over the past ten years, more than 200 divers have surveyed 2,406 ocean sites in 44 countries, creating a uniquely comprehensive data set on ocean life.

Reef Life Survey takes volunteers on surveying expeditions at hard-to-reach coral reefs around the world.
Rick Stuart-Smith/Reef Life Survey, Author provided

Lead author Professor Graham Edgar, who founded Reef Life Survey, said the unprecedented scope of their survey allowed them to investigate global patterns in marine life. The abundance of life in warm regions (such as tropical rainforests and coral reefs) has long intrigued naturalists. At least 30 theories have been put forward, but most studies have been based on relatively limited surveys restricted to a single continent or group of species.

By tapping into the recreational scuba diving community, Reef Life Survey has vastly increased the amount of information researchers have to work with. Professor Edgar and his colleagues provide one-on-one training to volunteers, teaching them how to carry out comprehensive scans of plants and animals in specific areas.

Dr Adriana Vergés, a researcher at the University of New South Wales specialising in the impact of climate change on ocean ecosystems, said that the Reef Life Survey has already substantially improved our understanding of the marine environment.

“For example, Reef Life Survey data has greatly contributed to our understanding of the factors that determine the effectiveness of effectiveness of marine-protected areas worldwide. The team have made all their data publicly available and more and more research is increasingly making use of it to answer research questions,” she said.

Some of the divers have been working with Reef Life Survey for a decade, although others participate when they can. One volunteer, according to Professor Edgar, was so inspired by the project that he began a doctorate in marine biology (he graduated this year).

There’s a strong link between fish numbers and water warmth, which means warming oceans are likely to change global fish distribution.
Rick Stuart-Smith/Reef Life Survey, Author provided

Warming oceans means fish on the move

One of the important insights delivered by the Reef Life Survey datatbase is the relationship between water temperature and the ratio of fish to invertebrates in an ecosystem. Essentially, the warmer the water, the more fish. Conversely, colder waters contain more invertebrates like lobster, crabs and shrimp.

Professor Stewart Frusher, director of the Centre for Marine Socioecology at the University of Tasmania (and a former colleague of Professor Edgar) told The Conversation that he believes we will see wide-scale changes in fish distribution as climate change warms the oceans.

“Species are moving into either deeper water or towards the poles. We also know that not all species are moving at the same rate, and thus new mixtures of ecosystems will occur, with the fast-moving species of one ecosystem mixing with the slower moving of another,” he said.

As species migrate or expand into newly warmed waters, according to Professor Frusher, they will compete with and prey on the species already living in that area. And while it’s uncertain exactly how disruptive this will be, we do know that small ecosystem changes can rapidly lead to larger-scale impacts.

In order to predict and manage these global changes, scientists need reliable and detailed world-wide data. Professor Frusher said that, with research funding declining, scientists do not have the resources to monitor at the scales required.

The Conversation“Well-developed citizen science programs fill an important niche for improving our understanding of how the earth is responding to change,” he said.

Madeleine De Gabriele, Deputy Editor: Energy + Environment, The Conversation

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

Will the National Energy Guarantee hit pause on renewables?


Frank Jotzo, Australian National University and Salim Mazouz, Australian National University

The federal government’s new National Energy Guarantee (NEG) proposal looks likely to put the brakes on renewable energy investment in Australia. And based on the sparse detail so far available, there are serious questions about whether the plan really can deliver on its aims of reliability, emissions reductions and lower prices.

The broad mechanism design could be made to work, but to be effective in driving the transition of the energy sector it would need adequate ambition on carbon emissions and very careful thought about the reliability requirements of the future electricity grid.


Read more: Infographic: the National Energy Guarantee at a glance


The policy may well be used to force investment into the fossil fuel power fleet through regulatory intervention, and perhaps for the power sector to buy emissions offsets. This would risk locking in a carbon-intensive power system.

The NEG: top or flop?

Having rejected several options – including an emissions intensity scheme, the Clean Energy Target put forward by the Finkel Review, and any continuation of the Renewable Energy Target – the government has finally managed to get a policy proposal through the party room, formulated in advice by its newly established Energy Security Board.

Analysts’ initial reactions have ranged from unbridled enthusiasm to derisive rejection. It depends on political judgments, expectations about how the scheme might operate in practice, and how high one’s expectations are for efficiency and environmental effectiveness.

The politics of this are complicated, but there are hopes that the Labor opposition will agree to the scheme in principle. But the decision is ultimately with the Australian states, which would need to pass legislation to implement it.

Reliability guarantee: supporting fossil fuels?

The first element of the NEG is the “reliability guarantee”. This would require electricity retailers to buy some share of their electricity from “dispatchable” sources that can be readily switched on. The NEG list includes coal and gas, as well as hydro and energy storage – essentially, anything except wind and solar.

The NEG proposal might be informed by a political imperative to support coal. As John Quiggin has pointed out, defining coal-fired plants as dispatchable is questionable at best: they have long ramp-up times and are sometimes unavailable.

The Australian Energy Market Operator (AEMO) would prescribe the share of the “dispatchable” power sources and perhaps also the mix of technologies in retailers’ portfolios, separately in each state. This would be a remarkably interventionist approach.

Demand from retailers for the power sources they are told to use could trigger investment in new gas generators, refurbishment of existing coal plants, and some investment in energy storage. It is difficult to see how it would force the building of new coal plants, given their very large upfront cost and long-term emissions liabilities.

Would electricity prices be lower, as the Energy Security Board’s advice claims? Investment in new power generation will tend to reduce prices, cutting into profit margins. But the resulting investments will come at higher economic cost than market solutions, because they are determined by regulators’ orders made with a view to the short-term energy mix, not long-term cost-effectiveness. And there would be risk premiums on project finance, reflecting uncertainty about future policy settings.

Emissions guarantee: flexible but weak?

The NEG’s second pillar is the “emissions guarantee”. This would require retailers to keep their portfolio below some level of emissions intensity (carbon dioxide per unit of electricity).

This increases the demand for electricity from lower-emissions technologies, allowing them to command higher market prices and therefore encouraging investment in them. This price signal would benefit renewables and also favour gas over coal, as well as discriminating against the most polluting coal plants.

The Energy Security Board’s advice suggests that retailers would have flexibility in complying with that obligation, by buying and selling emissions components of their contracts, and potentially also using emissions offsets from outside the scheme to make up for any exceeding of emissions limits.

The reliability and emissions elements of the NEG interact with each other, and the net effect depends on the detailed implementation as well as the relative importance of the two components.

Given the politics within government, the weight could be on support for coal and gas generation. The reliability guarantee could therefore end up putting a tight lid on the amount of new wind and solar that can enter the system.

Renewables, gas or credits?

The Energy Security Board makes explicit reference to Australia’s Paris target of a 26-28% reduction in emissions, relative to 2005 levels, by 2030. Prime Minister Malcolm Turnbull has said the NEG will be expected to cut electricity emissions by a similar percentage, as a “pro rata” contribution to this goal.

But to meet the economy-wide target, the electricity sector would need to make deeper cuts, because emissions reductions are cheaper and easier here than elsewhere.

The Energy Security Board says it expects renewables to reach 28-36% by 2030. This is rather low, considering that the Finkel Review projected 42% under its proposed clean energy target, and 35% under business as usual. Other analyses have shown that much higher levels of renewables are achievable.

So if the NEG is not geared to support renewables, how could significant emissions reductions be achieved?

One way would be to replace coal with gas-fired power, and brown coal with black coal. But the government has flagged that it is opposed to closing old coal plants. And a large-scale shift to gas would raise electricity prices further, unless gas prices were to tumble.


Read more: The government’s energy policy hinges on some tricky wordplay about coal’s role


That leaves another option, mentioned in the Energy Security Board’s report: power retailers could buy emissions offset credits from elsewhere to make up for not meeting the emissions standard, specifically from projects under the government’s Emissions Reduction Fund (ERF).

This might be attractive for the government, as electricity retailers would then pay for ERF credits, rather than government as has been the case until now. It may also be attractive to the power industry, as it would reduce the cost of complying with the new obligations. Retailers would pass on the costs to their customers, so electricity consumers would end up paying for ERF projects.

Even assuming that all of the ERF’s emissions reductions are real (and some of them may not be), all this does is shift the adjustment burden from electricity to other sectors such as agriculture.

The ConversationThe NEG has the potential to reduce emissions effectively if the parameters are adjusted accordingly. But what seems more likely is that it will put the brakes on investment in renewables, solidify the status quo and delay the energy transition.

Frank Jotzo, Director, Centre for Climate Economics and Policy, Australian National University and Salim Mazouz, Research Associate, Centre for Climate Economics and Policy, Australian National University

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

Swift parrots need protection from sugar gliders, but that’s not enough



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Without help, Tasmania’s swift parrots could be wiped out within three generations.
JJ Harrison/Wikimedia Commmons, CC BY-SA

Dejan Stojanovic, Australian National University; Matthew Webb, Australian National University, and Rob Heinsohn, Australian National University

Swift parrots are icons of Tasmania’s old-growth forests, but they’re also pretty tricky to find. These highly nomadic birds settle in a different place each year to breed, leaving nesting sites deserted for years between breeding events. This mobility makes them fascinating to study, but a nightmare to conserve.

Despite their elusive nature, we know enough about swift parrots to know they are under grave threat, particularly from Tasmania’s highly politicised logging industry.


Read more: Sugar gliders are eating swift parrots – but what’s to blame?


In the context of ongoing habitat loss to logging, swift parrots were listed as critically endangered, because of the impact of another surprising factor: predatory sugar gliders, an introduced species to Tasmania.

About half of the female swift parrots that attempt to nest in Tasmania are eaten by sugar gliders each year. This alone could be enough to wipe out swift parrots within three generations. To try and combat this, we are aiming to install mechanical doors on swift parrots’ nest boxes, which close at night to stop the nocturnal sugar gliders getting in.

A mechanical door that closes the entrance to swift parrot nest boxes at night, protecting them from predatory sugar gliders.

Happy campers by day.
ANU, Author provided
Safe and sound by night.
ANU, Author provided

Ongoing logging makes the issue even more pressing. Nests seem to be more vulnerable to sugar glider predation if nearby areas have been logged. This means that the ongoing deforestation from logging is likely to make the parrots’ plight even worse by both reducing available habitat and worsening predation risk.

Failure to protect swift parrots was a key reason why Sustainable Timber Tasmania (formerly Forestry Tasmania) failed to attain Forest Stewardship Council certification. Despite repeated attempts to resolve parrot protections over the past decade, logging continues to destroy known swift parrot nesting trees.

Recent logging in Tasmania’s Southern Forests.

Logging known swift parrot nest trees is against the recommendations of the industry regulator, the Forest Practices Authority. Yet Tasmania’s Regional Forest Agreement (RFA) exempts logging companies from federal conservation legislation.

The future of currently unlogged areas also remains uncertain. Many areas of known swift parrot habitat are scheduled for future logging, raising the prospect that yet more habitat will be cut down in the next few years.

Large areas of swift parrot habitat can still be legally logged under the Tasmanian Regional Forest Agreement, despite impacts on the critically endangered population.

While illegal logging of individual trees has been the subject of investigation under federal law, large areas of known swift parrot habitat are still being cut down, entirely legally, under the RFA.

This swift parrot nest hollow was felled by illegal wood cutters, resulting in an investigation.

Based on the existing evidence, we suggest that all logging of known swift parrot habitat should stop immediately. But given the recent renewal of the RFA and the intense politicisation of the forest industry in Tasmania, this kind of evidence-led rethink is unlikely to be forthcoming.

Protecting swift parrots is hard, because a truly effective strategy will require both large-scale habitat protection across Tasmania, and small-scale action such as our interventions against sugar glider predation.


Read more: Let’s stop Tasmania’s swift parrots going the way of the dodo


We are crowdfunding a project to install mechanical doors on 100 nest boxes deployed in sugar glider infested forest on mainland Tasmania.

Mobile species like swift parrots can’t be saved simply by creating a nature reserve and then walking away. Swift parrots are difficult to study and even more difficult to protect.

The ConversationWe need fresh thinking about how to manage these birds in landscapes used by the logging industry. Business as usual could easily end in extinction.

Dejan Stojanovic, Postdoctoral Fellow, Australian National University; Matthew Webb, , Australian National University, and Rob Heinsohn, Professor of Evolutionary and Conservation Biology, Australian National University

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

Mount Agung continues to rumble with warnings the volcano could still erupt


Heather Handley, Macquarie University

It’s more than three weeks since the alert level on Bali’s Mount Agung was raised to its highest level. An eruption was expected imminently and thousands of people were evacuated, but the volcano has still not erupted.

I keep getting emails from people asking me whether they should travel to Bali. I tell them to check the Australian’s government’s Smartraveller website, or contact their airline or tour operator.

They should also keep an eye on the media and any updates from the Indonesian Centre for Volcanology and Geological Hazard Mitigation.


Read more: Bali’s Mount Agung threatens to erupt for the first time in more than 50 years


Reports this week from the Indonesian National Disaster Management Authority show a decline in seismic energy recorded near the volcano.

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But does that mean the threat of any eruption is over?

A few false starts

The last major eruption of Mount Agung was in 1963. Since then, there have been two known periods of activity at the volcano site without an ensuing eruption.

In 1989, a few volcanic earthquakes occurred and hot, sulphur-rich gas emissions were observed with no eruption.

Between 2007 to 2009, satellite data showed inflation (swelling) of the volcano at a rate of about 8cm per year, probably caused by the inflow of new magma (molten rock) into the shallow plumbing system. This was followed by deflation for the next two years, again without an eruption.

The current volcanic activity – mainly the number of earthquakes – has not subsided since the alert level was raised to level 4. It continues to fluctuate at high levels, with more than 600 earthquakes a day. This indicates that the threat of an eruption is still high, despite a general decline in overall seismic energy.

This past weekend saw the highest number of daily earthquakes, with more than 1,100 recorded on Saturday October 14.

Graph showing the number of recorded earthquakes per day at Mount Agung volcano. The orange shows shallow volcanic earthquakes, light green is deep volcanic earthquakes and the blue is local tectonic earthquakes.
Centre for Volcanology and Geological Hazard Mitigation

The latest statement from the Indonesian Centre for Volcanology and Geological Hazard Mitigation was released on October 5. It said earthquake data indicates that pressure is continuing to build up under the volcano due to the increasing magma volume and as magma moves towards the surface.

It’s all about the gas

Magma contains dissolved gases (volatiles) such as water, carbon dioxide and sulphur dioxide. As magma moves towards the surface, the pressure becomes less and so gas bubbles form, akin to taking the top off a fizzy drink bottle. These gas bubbles take up additional space in the magma and increase the overall pressure of the system.

The amount of gas, and whether or not gas is able to escape from the magma prior to eruption, are major factors that determine how explosive (or not) any volcanic eruption will be.

If the gas bubbles forming in the magma stay within as it ascends beneath Mount Agung, then it could lead to a more explosive eruption. If the gas formed is able to escape, it might depressurise the system enough to erupt less violently or not at all.

White gas plumes, composed mainly of water vapour, have been observed. They have typically reached 50-200m above the crater rim at Mont Agung, and up to 1,500m on October 7. This water vapour is likely due to the hydrologic system heating up in response to the intruding magma at depth.

During the 1963 eruption, Mount Agung produced a significant amount of sulphur-rich gas that caused an estimated global cooling of 0.1-0.4℃. In this current phase of activity, we are yet to see any significant release of sulphur dioxide from the intruding magma.

How big would an eruption be?

It’s not easy to predict how big any eruption at Mount Agung would be. Analysis of volcanic material deposited during previous eruptions over the past 5,000 years suggests that about 25% of them have been of similar or larger size than the 1963 eruption.

On the neighbouring island of Java, the explosive 2010 eruption of Mount Merapi saw more than 400,000 people evacuated and 367 killed. This was preceded by increased earthquake activity over a period of about two months. It was the volcano’s largest eruption since 1872.

The monitoring data and studies of the volcanic rocks produced by the Merapi eruption suggest the relatively fast movement of a large volume of gas-rich magma was the reason for the unusually large eruption.


Read more: Ambae volcano’s crater lakes make it a serious threat to Vanuatu


In 2010, the Indonesian Center of Volcanology and Geological Hazard Mitigation issued timely forecasts of the size of the eruption phases at Merapi, saving an estimated 10,000–20,000 lives.

The waiting game

The Indonesians are keeping a close eye on seismic activity at Mount Agung and the public can watch a live seismogram.

Screenshot of the Mount Agung seismogram showing the large number of earthquakes recorded on October 13 and 14, 2017.
Indonesian Centre for Volcanology and Geological Hazard Mitigation

The last two eruptions of Mount Agung in 1843 and 1963 had a Volcanic Explosivity Index (VEI) of 5, on a scale of 0-8. A 0 would be something like a lava flow on Hawaii that you could generally walk or run from, and 8 would be a supervolcanic eruption like Yellowstone (640,000 years ago and 2.1 million years ago) in the United States or Toba (74,000 years ago) in North Sumatra, Indonesia.

Based on a history of explosive activity at the volcano, the Indonesian authorities are maintaining the current hazard zone of up to 12km from the summit of Mount Agung.

The ConversationIt’s still considered more likely than not that it will erupt, but the question remains: when?

Heather Handley, Associate Professor in Volcanology and Geochemistry, Macquarie University

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

Rising dragon: China’s carbon market exposes Australia’s energy paralysis


Peter Christoff, University of Melbourne

When China’s national carbon market is launched later this year it will be the world’s second-largest carbon market, after the European emissions trading scheme (ETS), which it will eventually overtake.

In sharp contrast, the absence of an explicit carbon price in Australia and persistent turbulence and confusion around domestic energy policy are hindering investment in renewable energy, leaving Australia lagging behind global trends in cutting emissions.

China will add to the cluster of national and sub-national emissions trading schemes that now exist in the European Union, Canada, the United States, Japan, South Korea and New Zealand.

As the World Bank Group’s 2016 report on the state and trends in carbon pricing indicated, up to a quarter of global emissions will then be covered by carbon pricing initiatives across some 40 national jurisdictions and 20 cities, states and regions. The evolution of regional carbon markets fostered by the Paris Agreement, in North Asia and elsewhere, will economically advantage those able to participate.



Copyright 2012 International Carbon Action Partnership – used with permission

For a brief time Australia flirted with being a global leader in carbon pricing and emissions trading. The Keating Labor Government debated – and rejected – a national carbon price in 1995. In 2009 the Rudd Labor government proposed laws to establish a national emissions trading scheme, the Carbon Pollution Reduction Scheme, which then failed in the Senate.


Read more: Obituary: Australia’s carbon price


Instead, Australia became the first country in the world to dismantle a national carbon price, when Tony Abbott axed Gillard Labor’s carbon tax. Now Australia is in danger of becoming an outlier globally – and this will have significant economic costs as well as environmental implications.

China’s climate leadership

When China became the world’s largest national greenhouse gas emitter in 2006, its involvement in any effective global emissions reduction agreement became an unavoidable responsibility.

China first acknowledged this internationally in 2009 when, at the climate negotiations in Copenhagen, it announced voluntary measures to improve national energy efficiency, pledging to cut its carbon dioxide emissions per unit of GDP by 40-45% below 2005 levels by 2020.

In 2014, China and the United States jointly announced their national targets and goals as a means of providing momentum for the following year’s Paris summit. China committed to an energy intensity target for 2030, lowering carbon dioxide emissions per unit of GDP by 60-65% below 2005 levels, and also to peak its emissions before 2030.


Read more: China and the US step up on climate


Indeed it appears already to have achieved this goal as a result of industrial modernisation and slowing economic growth, along with a push to reduce its reliance on coal and its global leadership in building renewable energy capacity (specifically, solar and wind).

Then, a decade after the launch of the European ETS, during a second joint announcement with the United States in September 2015, President Xi Jinping declared that China would establish a national carbon market by 2017.

China’s national ETS

Seven pilot emissions trading schemes have operated in China since 2013. These subnational projects – in five cities and two provinces, including Beijing, Chonqing, Guandong, Hubei, Shanghai, Shenzen and Tianjin – together already cover some 26.7% of China’s GDP in 2014.

They have employed slightly different market designs, varying the range of greenhouse gases and industry sectors covered, slightly different approaches to permit allocation, verification and compliance, and produced seven different carbon prices, at times ranging from some A$2.50 to up to A$22 per tonne.

The new national market represents a further step in the process of policy learning and systematic development, based on these experimental steps as well as the experience of the European ETS, which has evolved in several phases since 2005.

During its trial phase, from 2017 to 2019, policy makers will work to help new participants become familiar with the new national market and to improve its design. The market initially will be restricted in scope and size. It first will only include carbon dioxide and, like its pilots, its initial carbon price likely will be modest.

Guidelines from the National Development and Reform Commission indicate it will cover eight major industry sectors, such as power generation, petrochemicals, construction materials, pulp and paper, aviation, and iron, steel and aluminium production.

Nevertheless it is expected to cover some 40-50% of total Chinese emissions and eventually become a significant contributor to the suite of measures now being used to tackle Chinese emissions. Full implementation is expected to occur from 2020 onwards – with greater industry coverage, an increased percentage of allowances allocated by auction, and improved benchmarking.

A new measure among many

The new national carbon market is an additional response to the pressures that have driven Chinese climate and energy policy reforms over the past decade.

Domestically, a complex basket of tools are already in use to increase energy efficiency and reduce emissions. Coal-fired power generation has faced increasingly stringent regulation and new investment to counter dangerously high levels of air pollution in major cities, growing health problems and associated social unrest.


Read more: Want to see the business case for green energy? Just look at China


China’s heavy industries – economically sluggish, energy-inefficient and emissions-intensive – are under intensifying regulatory and now market pressure to modernise rapidly. While the carbon prices under the sub-national pilots have remained modest, they have added to this pressure for technological and economic reform.

National energy security is a strategic concern given China’s economic reliance on energy imports. The threats from global warming to China’s food and water security are recognised as concerns at the highest levels of government, including through the 13th Five-Year Plan.

China’s climate and energy policies also offer China an opportunity to demonstrate global leadership in climate policy, with the election of US President Donald Trump creating new diplomatic possibilities, a point emphasised in President Xi Jinping’s opening speech to the 19th Communist Party Congress, where he noted that China had taken a “driving seat in international cooperation to respond to climate change”.

Implications for Australia

A successful Chinese national emissions scheme has a range of impacts for Australia.

About a quarter of Australia’s coal exports (by volume) currently go to China, which in 2016 was Australia’s second biggest market for thermal coal and third biggest market for metallurgical coal.

If a national carbon market accelerates improvements in energy efficiency in China’s metals and power generation sectors, its demand for Australian coal exports – already beginning to contract – is likely to fall faster.

Second, for a quarter of a century, a succession of conservative Australian Prime Ministers justified the absence of a meaningful Australian climate policy by claiming there was no point in reducing emissions here because China wasn’t doing enough to tackle the problem.

Based on misrepresentations of what was happening in China, the Howard government delayed and then the Abbott government destroyed an Australian carbon pricing mechanism. Both leaders consistently stalled Australian climate policy, and continued to spruik the mirage of a national energy future based on exporting coal to ever larger overseas markets, including in China.

The ConversationIn all, the turbulent unpredictability of Australia’s climate politics and policies stands in contrast to China’s steady institutional commitment to accelerating decarbonisation. Given its present weak climate policy settings and institutions, and without a clear target for renewables, Australia will struggle to meet its current emission reduction commitments and will face increased future costs for failing to act sooner.

Peter Christoff, Associate Professor, School of Geography, University of Melbourne

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

Tropical thunderstorms are set to grow stronger as the world warms



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A supercell thunderstorm in the US state of Oklahoma.
Hamish Ramsay, Author provided

Martin Singh, Monash University

Thunderstorms are set to become more intense throughout the tropics and subtropics this century as a result of climate change, according to new research.

Thunderstorms are among nature’s most spectacular phenomena, producing lightning, heavy rainfall, and sometimes awe-inspiring cloud formations. But they also have a range of important impacts on humans and ecosystems.

For instance, lightning produced by thunderstorms is an important trigger for bushfires globally, while the hailstorm that hit Sydney in April 1999 remains Australia’s costliest ever natural disaster.


Read more: To understand how storms batter Australia, we need a fresh deluge of data


Given the damage caused by thunderstorms in Australia and around the world, it is important to ask whether they will grow in frequency and intensity as the planet warms.

Our main tools for answering such questions are global climate models – mathematical descriptions of the Earth system that attempt to account for the important physical processes governing the climate. But global climate models are not fine-scaled enough to simulate individual thunderstorms, which are typically only a few kilometres across.

But the models can tell us about the ingredients that increase or decrease the power of thunderstorms.

Brewing up a storm

Thunderstorms represent the dramatic release of energy stored in the atmosphere. One measure of this stored energy is called “convective available potential energy”, or CAPE. The higher the CAPE, the more energy is available to power updrafts in clouds. Fast updrafts move ice particles in the cold, upper regions of a thunderstorm rapidly upward and downward through the storm. This helps to separate negatively and positively charged particles in the cloud and eventually leads to lightning strikes.

To create thunderstorms that cause damaging wind or hail, often referred to as severe thunderstorms, a second factor is also required. This is called “vertical wind shear”, and it is a measure of the changes in wind speed and direction as you rise through the atmosphere. Vertical wind shear helps to organise thunderstorms so that their updrafts and downdrafts become physically separated. This prevents the downdraft from cutting off the energy source of the thunderstorm, allowing the storm to persist for longer.

By estimating the effect of climate change on these environmental properties, we can estimate the likely effects of climate change on severe thunderstorms.

Stormy forecast

My research, carried out with US colleagues and published today in Proceedings of the National Academy of Sciences, does just that. We examined changes in the energy available to thunderstorms across the tropics and subtropics in 12 global climate models under a “business as usual” scenario for greenhouse gas emissions.

In every model, days with high values of CAPE grew more frequent, and CAPE values rose in response to global warming. This was the case for almost every region of the tropics and subtropics.

These simulations predict that this century will bring a marked increase in the frequency of conditions that favour severe thunderstorms, unless greenhouse emissions can be significantly reduced.

Change in frequency (in days per year) of favourable conditions for severe thunderstorms for 2081-2100, compared with 1981-2000 averaged across 12 climate models under the RCP8.5 greenhouse-gas concentration scenario. Stippling indicates regions where 11 of the 12 models agree on the sign of the change.
CREDIT, Author provided

Previous studies have made similar predictions for severe thunderstorms in eastern Australia and the United States. But ours is the first to study the tropics and subtropics as a whole, a region that is characterised by some of the most powerful thunderstorms on Earth.

What drives the increased energy?

Different climate models, constructed by different research groups around the world, all agree that global warming will increase the energy available to thunderstorms – a prediction underlined by our new research. But we need to understand why this happens, so as to be sure that the effect is real and not a product of faulty model assumptions.

My colleagues and I previously proposed that high levels of CAPE can develop in the tropics as a result of the turbulent mixing that occurs when clouds draw in air from their surroundings. This mixing prevents the atmosphere from dissipating the available energy too quickly. Instead, the energy builds up for longer and is released in less frequent but more intense storms.

As the climate warms, the amount of water vapour required for cloud formation increases. This is the result of a well-known thermodynamic relationship called the Clausius-Clapeyron relation. In a warmer climate this means the difference in the humidity between the clouds and their surroundings becomes larger. As a result, the mixing mechanism becomes more efficient in building up the available energy. This, we argue, accounts for the increase in CAPE seen in our model simulations.

In our new study, we tested this idea in a global climate model by artificially increasing the strength of the mixing between clouds and their surroundings. As expected, this change produced a large increase in the energy available to thunderstorms in our model.


Read more: Australia faces a stormier future thanks to climate change


Another prediction of our hypothesis is that days with both high values of CAPE and heavy precipitation tend to occur when the atmosphere is least humid in its middle levels (at altitudes of a few kilometres). Using real data from weather balloons, we confirmed that this is the case across the tropics and subtropics.

What this means for future thunderstorms

The models predict that the energy available for thunderstorms will increase as the Earth warms. But how much more intense will storms actually become as a result?

The answer to that question is currently uncertain, and answering it is the next job for me, and other researchers around the world.

The ConversationBut it is clear that through our continued greenhouse gas emissions, we are increasing the fuel available to the strongest thunderstorms. Exactly how much stronger our future thunderstorms will ultimately become remains to be seen.

Martin Singh, Lecturer, School of Earth, Atmosphere and Environment, Monash University

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