Why we shouldn’t be too quick to blame migratory animals for global disease

Alice Risely, Deakin University; Bethany J Hoye, University of Wollongong, and Marcel Klaassen, Deakin University

Have you ever got on a flight and the person next to you started sneezing? With 37 million scheduled flights transporting people around the world each year, you might think that the viruses and other germs carried by travellers would be getting a free ride to new pastures, infecting people as they go.

Yet pathogenic microbes are surprisingly bad at expanding their range by hitching rides on planes. Microbes find it difficult to thrive when taken out of their ecological comfort zone; Bali might just be a tad too hot for a Tasmanian parasite to handle.

But humans aren’t the only species to go global with their parasites. Billions of animals have been flying, swimming and running around the globe every year on their seasonal migrations, long before the age of the aeroplane. The question is, are they picking up new pathogens on their journeys? And if they are, are they transporting them across the world?

Read more: A tale of three mosquitoes: how a warming world could spread disease

Migratory animals are the usual suspects for disease spread

With the rate of zoonotic diseases (pathogens that jump from animals to humans) on the rise, migratory animals have been under increasing suspicion of aiding the spread of devastating diseases such as bird flu, Lyme disease, and even Ebola.

These suspicions are bad for migrating animals, because they are often killed in large numbers when considered a disease threat. They are also bad for humans, because blaming animals may obscure other important factors in disease spread, such as animal trade. So what’s going on?

Despite the logical link between animal migration and the spread of their pathogens, there is in fact surprisingly little direct evidence that migrants frequently spread pathogens long distances.

This is because migratory animals are notoriously hard for scientists to track. Their movements make them difficult to test for infections over the vast areas that they occupy.

But other theories exist that explain the lack of direct evidence for migrants spreading pathogens. One is that, unlike humans who just have to jump on a plane, migratory animals must work exceptionally hard to travel. Flying from Australia to Siberia is no easy feat for a tiny migratory bird, nor is swimming between the poles for giant whales. Human athletes are less likely to finish a race if battling infections, and likewise, migrant animals may have to be at the peak of health if they are to survive such gruelling journeys. Sick travellers may succumb to infection before they, or their parasitic hitchhikers, reach their final destination.

Put simply, if a sick animal can’t migrate, then neither can its parasites.

On the other hand, migrants have been doing this for millennia. It is possible they have adapted to such challenges, keeping pace in the evolutionary arms race against pathogens and able to migrate even while infected. In this case, pathogens may be more successful at spreading around the world on the backs of their hosts. But which theory does the evidence support?

Sick animals can still spread disease

To try and get to the bottom of this question, we identified as many studies testing this hypothesis as we could, extracted their data, and combined them to look for any overarching patterns.

We found that infected migrants across species definitely felt the cost of being sick: they tended to be in poorer condition, didn’t travel as far, migrated later, and had lower chances of survival. However, infection affected these traits differently. Movement was hit hardest by infection, but survival was only weakly impacted. Infected migrants may not die as they migrate, but perhaps they restrict long-distance movements to save energy.

So pathogens seem to pose some costs on their migratory hosts, which would reduce the chances of migrants spreading pathogens, but perhaps not enough of a cost to eliminate the risk completely.

Read more: Giant marsupials once migrated across an Australian Ice Age landscape

But an important piece of the puzzle is still missing. In humans, travelling increases our risk of getting ill because we come into contact with new germs that our immune system has never encountered before. Are migrants also more susceptible to unfamiliar microbes as they travel to new locations, or have they adapted to this as well?

Guts of migrants resistant to microbial invasion

To investigate the susceptibility of migrants, we went in a different direction and decided to look at the gut bacteria of migratory shorebirds – grey, unassuming birds that forage on beaches or near water, and that undergo some of the longest and fastest migrations in the animal kingdom.

Most animals have hundreds of bacterial species living in their guts, which help break down nutrients and fight off potential pathogens. Every new microbe you ingest can only colonise your gut if the environmental conditions are to its liking, and competition with current residents isn’t too high. In some cases, it may thrive so much it becomes an infection.

The Red-necked stint is highly exposed to sediment microbes as it forages for the microscopic invertebrates that fuel its vast migrations.
Author provided

We found the migratory shorebirds we studied were exceptionally good at resisting invasion from ingested microbes, even after flying thousands of kilometres and putting their gut under extreme physiological strain. Birds that had just returned from migration (during which they stopped in many places in China, Japan, and South East Asia), didn’t carry any more species of bacteria than those that had stayed around the same location for a year.

The ConversationAlthough these results need to be tested in other migratory species, our research suggests that, like human air traffic, pathogens might not get such an easy ride on their migratory hosts as we might assume. There is no doubt that migrants are involved in pathogen dispersal to some degree, but there is increasing evidence that we shouldn’t jump the gun when it comes to blaming migrants.

Alice Risely, PhD candidate in Ecology, Deakin University; Bethany J Hoye, Lecturer in Animal Ecology, University of Wollongong, and Marcel Klaassen, Alfred Deakin Professor and Chair in Ecology, Deakin University

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

Australia is a global top-ten deforester – and Queensland is leading the way

Noel D Preece, James Cook University and Penny van Oosterzee, James Cook University

When you think of devastating deforestation and extinction you usually think of the Amazon, Borneo and the Congo. But eastern Australia ranks alongside these in the top 10 of the world’s major deforestation fronts – the only one in a developed nation. Most of the clearing is happening in Queensland, and it is accelerating.

Only last year a group of leading ecologists voiced their alarm at new data which showed the clearing of 296,000 hectares of forest in 2013-14. This was three times higher than in 2008-09, kicking Australia up the list as one of the world’s forest-clearing pariahs. At the 2016 Society for Conservation Biology Conference, a Scientists’ Declaration was signed by hundreds of scientists, expressing concern at these clearing rates.

Read more: Queensland land clearing is undermining Australia’s environmental progress

But the latest snapshot, Queensland’s Department of Science report on land cover change published last month, showed a staggering 395,000ha of clearing for 2015-16: an increase of one third on 2014-15. As far as we can tell this rate of increased clearing is unmatched anywhere else on the globe.

showed a staggering 395,000 of clearing for 2015-16: which is an increase of one third on 2014-15, or 133% over the period

Strong vegetation management laws enacted in Queensland – the Vegetation Management Act 1999 – achieved dramatic reductions in forest and woodland loss. But the subsequent Liberal National state government, elected in 2012, overturned these protections.

The current government, elected in 2015, has tried and failed to reinstate the protections. In response, “panic clearing” caused clearing rates to shoot up, in anticipation that the state election will deliver a government that will reintroduce the much-needed protection of forests.

The Queensland Parliament is now in caretaker mode ahead of the November 25 election. The Queensland Labor Party has pledged to reinstate laws to prevent wholesale clearing, while the LNP opposition has vowed to retain current clearing rates.

Forest cleared by bulldozers towing massive chains.
Noel Preece

Australian community and wildlife lose

Whichever way you look at it, there is not a lot of sense in continued clearing. Australia already has some of the highest extinction rates on the planet for plants and animals. With 80% of Queensland’s threatened species living in forest and woodland, more clearing will certainly increase that rate.

Clearing also kills tens of millions of animals across Australia each year, a major animal welfare concern that rarely receives attention. This jeopardises both wildlife and the A$140 million invested in threatened species recovery.

Read more: Land clearing isn’t just about trees – it’s an animal welfare issue too

This rate of clearing neutralises our major environment programs. Just one year of clearing has removed more trees than the bulk of 20 million trees painstakingly planted, at a cost of A$50 million. Australia’s major environment programs simply can’t keep up, and since 2013 are restoring only one-tenth of the extent of land bulldozed just last year.

Restoration costs to improve the quality of waters running onto the Great Barrier Reef are estimated at around A$5 billion to A$10 billion over 10 years. Nearly 40% of the land cleared in Queensland is in reef catchments, which will reverse any water quality gains as sediment pours onto the reef.

Climate efforts nullified

Since 2014, the federal government has invested A$2.55 billion on reducing emissions in the Carbon Farming Initiative through the Emissions Reduction Fund. Currently 189 million tonnes of abatement has been delivered by the Emissions Reduction Fund. This – the central plank of the Australian government’s climate response – will be all but nullified by the end of 2018 with the current clearing rates, and will certainly be wiped out by 2020, when Australia is expected to meet its climate target of 5% below 2000 emissions.

Ironically, this target will be achieved with the help of carried-over results from the first commitment period of the Kyoto Protocol, which Australia was only able to meet because land clearing had decreased between 1990 and 1997.

Why is this happening?

Most of the clearing in Queensland since 1999 has been for pasture. Most good cropping land was cleared decades ago. Removing trees in more marginal lands can increase the carrying capacity for a short time with an immediate, and usually short-lived, financial reward. These rewards come at the expense of long-term sustainability, which future landholders and government will bear.

Large areas of the cleared lands have been subject to substantial erosion and nutrient loss from the newly cleared lands, and land degradation over time, and some areas have suffered massive woody weed incursions.

This is playing out today across the north where pastoralism is a marginal activity at best, with declining terms of trade of about 2% per year, with no net productivity growth, high average debts and low returns, and many enterprises facing insolvency. Clearing vegetation won’t change that.

A recent preliminary valuation of ecosystem services, on the other hand, estimated that uncleared lands are worth A$3,300-$6,100 per hectare per year to the Australian community, compared with productivity of grazing lands of A$18 per hectare.

With a clear divide between the policies Labor and the LNP are taking to the election, now is a good time to give land clearing’s social, economic and environmental impact the scrutiny it deserves.

The ConversationThis article was updated on November 21 to reflect that land clearing increased in by a third in 2015-16 over 2014-15 levels. Previously the article stated an increase of 133%.

Noel D Preece, Adjunct Principal Research Fellow at Charles Darwin and, James Cook University and Penny van Oosterzee, Principal Research Adjunct James Cook University and University Fellow Charles Darwin University, James Cook University

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

Time for a global agreement on minerals to fuel the clean energy transition

Damien Giurco, University of Technology Sydney; Nicholas Arndt, Université Grenoble Alpes, and Saleem H. Ali, The University of Queensland

Representatives from around the world are meeting in Bonn this week to discuss progress towards the goals of the Paris climate agreement. A large part of this challenge involves rapidly scaling up the deployment of renewable energy, while curbing fossil fuel use – but little attention has been paid to the minerals that will be needed to build these technologies.

Wind and solar infrastructure, batteries and electric vehicles all require vast amounts of mined (and recycled) resources. These range from copper for wires and electric motors, to lithium and cobalt for batteries, to smaller amounts of rare metals like indium and gallium for solar cells.

Read more: Mining for metals in society’s waste

The problem is that the current system for mining these minerals is not always efficient; it’s polluting and is subject to increased social pressure and public protests. Instead, we need a new international mechanism to coordinate global mineral exploration that looks to our future supply needs.

As technology advances, more and different metals are needed.
Zepf V, Reller A, Rennie C, Ashfield M & Simmons J, BP (2014): Materials critical to the energy industry.

Challenges for minerals supply

While the Paris agreement has created a global framework for managing carbon, nothing similar exists for minerals. This leaves the pursuit of sustainable resource development largely in the hands of mining companies and state-owned enterprises.

Mining these resources generates significant water and air pollution. This problem is increasing: for example, global copper ore quality is declining over time. That means that copper mining now requires excavating twice as much ore as ten years ago to yield the same amount of copper, creating much more mine waste.

Read more: Treasure from trash: how mining waste can be mined a second time

Lower commodity prices have meant that investment in exploring new mine sites has fallen. But it takes a long time to develop new mines – it can often take 20 years to go from finding a metal deposit to beginning mining, and only around 20% of discoveries since 2000 have led to an operating mine.

Lack of investment in exploration is driven by short-term thinking, rather than a long-term plan to supply rising demand.

In parallel, resistance to mining, often at a local level, is increasing worldwide. Environmental catastrophes, of which there have been many examples, erode social trust, often delaying or stopping mine development.

A new global mechanism to more effectively plan resource supply could help rebuild trust in local communities, limit price spikes to ensure equitable access to metal resources, and balance the international tension which arises as industries and governments compete for minerals from a shrinking list of countries able to tolerate and profit from sustaining a mining industry.

A global agreement on mineral resources

Developing a global mechanism will of course be difficult, requiring substantive dialogue and strong leadership. But there are organisations that could step up, such as the United Nations Environment Assembly, or the newly established Intergovernmental Forum on Mining Metals and Sustainable Development.

The global community is well aware of the threat that rising sea levels pose to low-lying countries. We need similar awareness of the crucial role minerals are playing in the energy transition, and the risk that supply problems could derail sustainability goals.

To that end, we need to globally coordinate several crucial aspects of mineral development. To start with, while most detailed information on where minerals are mined and sold is privately held, there is publicly available data that could be used to predict possible imbalances in supply and demand internationally (for example copper, iron, lithium, indium). Publicly-funded institutions have an important role here. They can assess how known supply will meet future demand, and deliver insight into the changing environmental impact.

It should also be entirely possible to develop inventories of recyclable metals, which can be an important supplement to large mining operations.

Compiling inventories of recyclable metals is underway across Europe as part of a move towards a circular economy (where as much waste as possible is repurposed).

Read more: Explainer: what is the circular economy

While recycling for for metals like lithium for less than 1%, around 40% of steel demand is met from scrap recycled during manufacturing and from end-of-life products and infrastructure. Thinking smarter about eventual dismantling of buildings at the time when they are built, can support better use of recycled resources.

Geoscience agencies already offer maps of underground minerals, demonstrating that this kind of co-ordinated perspective is feasible. Extending this approach to recyclables can mitigate environmental impact and ease the social objections to new mines.

A global mechanism for mineral exploration and supply could also be an opportunity to promote best-practice for responsible mining, with a focus on social license and fair and transparent royalty arrangements.

Overcoming resistance

It’s a challenging proposition, especially as many countries display less enthusiasm for international agreements. However, it will be increasingly difficult to meet the Paris targets without tackling this problem.

In the decades ahead, our mineral supply will still need to double or triple to meet the demand for electric vehicles and other technologies required by our growing global population.

In short, resource efficiency and jobs of the future depend on an assured mineral supply. This should be a nonpartisan issue, across the global political spectrum.

The ConversationThe authors gratefully acknowledge the contribution of Edmund Nickless, Chair, New Activities Strategic Implementation Committee, International Union of Geological Sciences to this article.

Damien Giurco, Professor of Resource Futures, University of Technology Sydney; Nicholas Arndt, Professor of Geosciences, Université Grenoble Alpes, and Saleem H. Ali, Distinguished Professor of Energy and the Environment, University of Delaware (USA); Professorial Research Fellow, The University of Queensland

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

Australia emits mercury at double the global average

Robyn Schofield, University of Melbourne

A report released this week by advocacy group Environmental Justice Australia presents a confronting analysis of toxic emissions from Australia’s coal-fired power plants.

The report, which investigated pollutants including fine particles, nitrogen oxides and sulfur dioxide, also highlights our deeply inadequate mercury emissions regulations. In New South Wales the mercury emissions limit is 666 times the US limits, and in Victoria there is no specific mercury limit at all.

This is particularly timely, given that yesterday the Minamata Convention, a United Nations treaty limiting the production and use of mercury, entered into force. Coal-fired power stations and some metal manufacturing are major sources of mercury in our atmosphere, and Australia’s per capita mercury emissions are roughly double the global average.

Read more: Why won’t Australia ratify an international deal to cut mercury pollution?

In fact, Australia is the world’s sixteenth-largest emitter of mercury, and while our government has signed the Minamata convention it has yet to ratify it. According to a 2016 draft impact statement from the Department of Environment and Energy:

Australia’s mercury pollution occurs despite existing regulatory controls, partly because State and Territory laws limit the concentration of mercury in emissions to air […] but there are few incentives to reduce the absolute level of current emissions and releases over time.

Mercury can also enter the atmosphere when biomass is burned (either naturally or by people), but electricity generation and non-ferrous (without iron) metal manufacturing are the major sources of mercury to air in Australia. Electricity generation accounted for 2.8 tonnes of the roughly 18 tonnes emitted in 2015-16.

Mercury in the food web

Mercury is a global pollutant: no matter where it’s emitted, it spreads easily around the world through the atmosphere. In its vaporised form, mercury is largely inert, although inhaling large quantities carries serious health risks. But the health problems really start when mercury enters the food web.

I’ve been involved in research that investigates how mercury moves from the air into the food web of the Southern Ocean. The key is Antartica’s sea ice. Sea salt contains bromine, which builds up on the ice over winter. In spring, when the sun returns, large amounts of bromine is released to the atmosphere and causes dramatically named “bromine explosion events”.

Essentially, very reactive bromine oxide is formed, which then reacts with the elemental mercury in the air. The mercury is then deposited onto the sea ice and ocean, where microbes interact with it, returning some to the atmosphere and methylating the rest.

Once mercury is methylated it can bioaccumulate, and moves up the food chain to apex predators such as tuna – and thence to humans.

As noted by the Australian government in its final impact statement for the Minamata Convention:

Mercury can cause a range of adverse health impacts which include; cognitive impairment (mild mental retardation), permanent damage to the central nervous system, kidney and heart disease, infertility, and respiratory, digestive and immune problems. It is strongly advised that pregnant women, infants, and children in particular avoid exposure.

Read more: Climate change set to increase air pollution deaths by hundreds of thousands

Australia must do better

A major 2009 study estimated that reducing global mercury emissions would carry an economic benefit of between US$1.8 billion and US$2.22 billion (in 2005 dollars). Since then, the US, the European Union and China have begun using the best available technology to reduce their mercury emissions, but Australia remains far behind.

But it doesn’t have to be. Methods like sulfur scrubbing, which remove fine particles and sulfur dioxide, also can capture mercury. Simply limiting sulfur pollutants of our power stations can dramatically reduce mercury levels.

Ratifying the Minamata Convention will mean the federal government must create a plan to reduce our mercury emissions, with significant health and economic benefits. And because mercury travels around the world, action from Australia wouldn’t just help our region: it would be for the global good.

The ConversationIn an earlier version of this article the standfirst referenced a 2006 study stating Australia is the fifth largest global emitter of mercury. Australia is now 16th globally.

Robyn Schofield, Senior Lecturer for Climate System Science and Director of Environmental Science Hub, University of Melbourne

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

Solar is now the most popular form of new electricity generation worldwide

Andrew Blakers, Australian National University

Solar has become the world’s favourite new type of electricity generation, according to global data showing that more solar photovoltaic (PV) capacity is being installed than any other generation technology.

Worldwide, some 73 gigawatts of net new solar PV capacity was installed in 2016. Wind energy came in second place (55GW), with coal relegated to third (52GW), followed by gas (37GW) and hydro (28GW).


Together, PV and wind represent 5.5% of current energy generation (as at the end of 2016), but crucially they constituted almost half of all net new generation capacity installed worldwide during last year.

It is probable that construction of new coal power stations will decline, possibly quite rapidly, because PV and wind are now cost-competitive almost everywhere.

Hydro is still important in developing countries that still have rivers to dam. Meanwhile, other low-emission technologies such as nuclear, bio-energy, solar thermal and geothermal have small market shares.

PV and wind now have such large advantages in terms of cost, production scale and supply chains that it is difficult to see any other low-emissions technology challenging them within the next decade or so.

That is certainly the case in Australia, where PV and wind comprise virtually all new generation capacity, and where solar PV capacity is set to reach 12GW by 2020. Wind and solar PV are being installed at a combined rate of about 3GW per year, driven largely by the federal government’s Renewable Energy Target (RET).

This is double to triple the rate of recent years, and a welcome return to growth after several years of subdued activity due to political uncertainty over the RET.

If this rate is maintained, then by 2030 more than half of Australian electricity will come from renewable energy and Australia will have met its pledge under the Paris climate agreement purely through emissions savings within the electricity industry.

To take the idea further, if Australia were to double the current combined PV and wind installation rate to 6GW per year, it would reach 100% renewable electricity in about 2033. Modelling by my research group suggests that this would not be difficult, given that these technologies are now cheaper than electricity from new-build coal and gas.

Renewable future in reach

The prescription for an affordable, stable and achievable 100% renewable electricity grid is relatively straightforward:

  1. Use mainly PV and wind. These technologies are cheaper than other low-emission technologies, and Australia has plenty of sunshine and wind, which is why these technologies have already been widely deployed. This means that, compared with other renewables, they have more reliable price projections, and avoid the need for heroic assumptions about the success of more speculative clean energy options.

  2. Distribute generation over a very large area. Spreading wind and PV facilities over wide areas – say a million square kilometres from north Queensland to Tasmania – allows access to a wide range of different weather, and also helps to smooth out peaks in users’ demand.

  3. Build interconnectors. Link up the wide-ranging network of PV and wind with high-voltage power lines of the type already used to move electricity between states.

  4. Add storage. Storage can help match up energy generation with demand patterns. The cheapest option is pumped hydro energy storage (PHES), with support from batteries and demand management.

Australia currently has three PHES systems – Tumut 3, Kangaroo Valley, and Wivenhoe – all of which are on rivers. But there is a vast number of potential off-river sites.

Potential sites for pumped hydro storage in Queensland, alongside development sites for solar PV (yellow) and wind energy (green). Galilee Basin coal prospects are shown in black.
Andrew Blakers/Margaret Blakers, Author provided

In a project funded by the Australian Renewable Energy Agency, we have identified about 5,000 sites in South Australia, Queensland, Tasmania, the Canberra district, and the Alice Springs district that are potentially suitable for pumped hydro storage.

Each of these sites has between 7 and 1,000 times the storage potential of the Tesla battery currently being installed to support the South Australian grid. What’s more, pumped hydro has a lifetime of 50 years, compared with 8-15 years for batteries.

Importantly, most of the prospective PHES sites are located near where people live and where new PV and wind farms are being constructed.

Once the search for sites in New South Wales, Victoria and Western Australia is complete, we expect to uncover 70-100 times more PHES energy storage potential than required to support a 100% renewable electricity grid in Australia.

Potential PHES upper reservoir sites east of Port Augusta, South Australia. The lower reservoirs would be at the western foot of the hills (bottom of the image).
Google Earth/ANU

Managing the grid

Fossil fuel generators currently provide another service to the grid, besides just generating electricity. They help to balance supply and demand, on timescales down to seconds, through the “inertial energy” stored in their heavy spinning generators.

But in the future this service can be performed by similar generators used in pumped hydro systems. And supply and demand can also be matched with the help of fast-response batteries, demand management, and “synthetic inertia” from PV and wind farms.

Wind and PV are delivering ever tougher competition for gas throughout the energy market. The price of large-scale wind and PV in 2016 was A$65-78 per megawatt hour. This is below the current wholesale price of electricity in the National Electricity Market.

Abundant anecdotal evidence suggests that wind and PV energy price has fallen to A$60-70 per MWh this year as the industry takes off. Prices are likely to dip below A$50 per MWh within a few years, to match current international benchmark prices. Thus, the net cost of moving to a 100% renewable electricity system over the next 15 years is zero compared with continuing to build and maintain facilities for the current fossil-fuelled system.

Gas can no longer compete with wind and PV for delivery of electricity. Electric heat pumps are driving gas out of water and space heating. Even for delivery of high-temperature heat for industry, gas must cost less than A$10 per gigajoule to compete with electric furnaces powered by wind and PV power costing A$50 per MWh.

Importantly, the more that low-cost PV and wind is deployed in the current high-cost electricity environment, the more they will reduce prices.

Then there is the issue of other types of energy use besides electricity – such as transport, heating, and industry. The cheapest way to make these energy sources green is to electrify virtually everything, and then plug them into an electricity grid powered by renewables.

A 55% reduction in Australian greenhouse gas emissions can be achieved by conversion of the electricity grid to renewables, together with mass adoption of electric vehicles for land transport and electric heat pumps for heating and cooling. Beyond this, we can develop renewable electric-driven pathways to manufacture hydrocarbon-based fuels and chemicals, primarily through electrolysis of water to obtain hydrogen and carbon capture from the atmosphere, to achieve an 83% reduction in emissions (with the residual 17% of emissions coming mainly from agriculture and land clearing).

Doing all of this would mean tripling the amount of electricity we produce, according to my research group’s preliminary estimate.

The ConversationBut there is no shortage of solar and wind energy to achieve this, and prices are rapidly falling. We can build a clean energy future at modest cost if we want to.

Andrew Blakers, Professor of Engineering, Australian National University

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

How trade policies can support global efforts to curb climate change

File 20170726 23211 sgmupo
Eliminating trade barriers on green technologies could help countries to shift away from fossil fuels.
from www.shutterstock.com, CC BY-ND

Adrian Henry Macey, Victoria University of Wellington

Climate change will have a big impact on the global economy as nations seek to adapt to a warmer world and adopt policies to keep global warming below two degrees. In the wake of the US withdrawal from the Paris Agreement, it is important that policies around trade and investment support national efforts to adapt to global warming while trying to curb it. Four issues stand out:

1. Border tax adjustments

Border tax adjustments, or BTAs, refer to import taxes on goods from countries where companies do not have to pay for their emissions.

This is highly controversial and problematic for practical reasons and difficult to reconcile with World Trade Organisation (WTO) compliance requirements. The arguments in favour rest on punishing free riders and protecting the competitiveness of national firms subject to climate change costs in their home country. Such taxes are also held up as a way of avoiding “carbon leakage” caused by production shifting to countries with more lax climate change policies.

The latter two arguments are similar to those that have been applied in the past to environmental protection regulations. The problem with them is that there is very poor empirical evidence for either competitiveness risk or for carbon leakage.
They also rest on the assumption that combating climate change is always a net cost. This is being increasingly challenged.

The argument against BTAs centres on the potential of unilateral measures being used to coerce developing countries. The sensitivity of such measures is shown by the fact that, until very late in the negotiations of the Paris Agreement, developing countries insisted on including the following clause.

“Developed country parties shall not resort to any form of unilateral measures against goods and services from developing country parties on any grounds related to climate change.”

2. Trade liberalisation in climate-friendly goods and services

Eliminating trade barriers on solar panels and other green technologies could help countries to shift away from fossil fuels. This is fully within the scope of the WTO and indeed the mandate of the current Doha trade round. There are several work streams within the WTO covering this area, though progress is slow.

3.International carbon trading and offsets

The Kyoto Protocol includes several mechanisms (Clean Development Mechanism, Joint Implementation and Emissions Trading) that can be used by countries that have tabled a 2020 target (European countries and Australia).

International market mechanisms beyond 2020 have not yet been created under the Paris Agreement but its Article 6 foresees them. Such mechanisms are being developed bottom-up by groups of countries, which can make much faster progress than is possible within the United Nations Framework Convention on Climate Change (UNFCCC).

However, any new mechanisms are likely to be linked in some way to the UNFCCC. There is no coverage of carbon trading under the WTO at present and there appears to be no appetite for bringing it within WTO disciplines.

4. Compatibility of climate measures and trade rules

One fear is that WTO rules will have a chilling effect on climate change measures such as subsidies, technical regulations or bans on certain products. However, Article 3.5 of the UNFCCC (which applies to the Paris Agreement as it does to the earlier Kyoto Protocol) is clear.

It uses WTO language to state that “measures taken to combat climate change, including unilateral ones, should not constitute a means of arbitrary or unjustifiable discrimination or a disguised restriction on international trade”. The UNFCCC, like the WTO, acknowledges the legitimate purpose of climate measures, including that they may involve restrictions on trade.

There is ample and growing WTO jurisprudence on measures taken for environmental purposes which confirms their legitimacy in WTO law. The jurisprudence is not static; it evolves with international thinking as expressed in treaties and less formal agreements.

Helpfully the WTO Treaty (1994) included an objective relating to protection and preservation of the environment that went further than the earlier General Agreement on Tariffs and Trade (GATT). This provision has already been used in interpretation by the highest WTO jurisdiction, the Appellate Body.


I expect that some carbon markets will develop amongst carbon clubs. Trading rules will be determined by those countries involved and will rest on the environmental integrity of the units traded.

Border tax adjustments (BTAs) are problematic. Some commentators have predicted a climate change trade war, arguing that countries are vulnerable if their climate measures are seen as inadequate.

This is now an improbable scenario. Any attempt to impose BTAs against countries which have signed up to the Paris Agreement would face enormous practical difficulties. It would also risk undoing the international consensus.

Transparency, peer review and naming and shaming of countries with inadequate pledges (Nationally Determined Contribution or NDCs), or countries that fail to implement an adequate one, may prove more effective than any of these unilateral measures. Evidence from the climate change negotiations is that countries do care about their reputation.

A further resource to encourage countries to act would be carbon clubs, where countries wanting to accelerate their transition to a low-carbon economy would link their climate measures through a common carbon price via their emissions trading schemes.

The threat of BTAs – clearly foreseen by major American companies after the Trump Administration’s decision to leave the Paris Agreement – may be a useful political lever to gain cooperation. But there are other ways of achieving similar ends.

The ConversationOne example is to require all goods, domestic or imported, to meet sustainability standards. This is potentially allowable under the WTO Technical Barriers to Trade agreement (TBT) as a type of processing and production method. But even if not, the existence of the Paris Agreement – a universal agreement with clear objectives and requirements on all parties to act on climate change – would be a useful reference in any dispute settlement proceedings.

Adrian Henry Macey, Senior Associate, Institute for Governance and Policy Studies; Adjunct Professor, New Zealand Climate Change Research Institute. , Victoria University of Wellington

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