Climate explained: does building and expanding motorways really reduce congestion and emissions?

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Simon Kingham, University of Canterbury

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Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

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Q: Does building and expanding motorways really reduce congestion and emissions, or does it increase it?

Historically, building more and wider roads, including motorways, was seen as a way of reducing congestion. This in turn is supposed to lower emissions.

The new motorways of the future.

Fuel efficiency is optimised for driving at around 80kmh and it decreases the faster you go above that. But with speed limits up to 110kmh, people are likely to drive above 80kmh on motorways — and this means building and expanding motorways will actually increase emissions.

Many countries, especially in Europe, are now looking to lower speed limits partly to reduce emissions.

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Remove car lanes, restrict vehicles and improve transit to reduce traffic congestion

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In addition to speeding, rapid acceleration and braking can lower mileage by 15-30% at highway speeds and 10-40% in stop-and-go traffic. If building or expanding motorways did reduce congestion, the smoother driving would be a benefit.

But this assumption is not backed by evidence. Research shows even on roads with no impediments drivers brake and accelerate unnecessarily, increasing congestion and emissions.

One of the arguments for future autonomous vehicles is that such braking and accelerating should not occur and emissions should reduce.

New roads, new drivers

The most significant impact new and expanded motorways have on congestion and emissions is the effect on the distance people travel.

Historically, engineers assumed cars (and more pertinently their drivers) would behave like water. In other words, if you had too much traffic for the road space provided, you would build a new road or expand an existing one and cars would spread themselves across the increased road space.

Congested traffic on a motorway into the centre of Auckland.
patjo/Shutterstock

Unfortunately, this is not what happens. New road capacity attracts new drivers. In the short term, people who had previously been discouraged from using congested roads start to use them.

In the longer term, people move further away from city centres to take advantage of new roads that allow them to travel further faster.

This is partly due to the “travel time budget” — a concept also known as Marchetti’s constant — which suggests people are prepared to spend around an hour a day commuting. Cities tend to grow to a diameter of one-hour travel time.

City sprawl

The concept is supported by evidence that cities have sprawled more as modes of transport have changed. For example, cities were small when we could only walk, but expanded along transport corridors with rail and then sprawled with the advent of cars. This all allows commuters to travel greater distances within the travel time budget.

Building or expanding roads releases latent demand — widely defined as “the increment in new vehicle traffic that would not have occurred without the improvement of the network capacity”.

This concept is not new. The first evidence of it can be found back in the 1930s. Later research in 1962 found that “on urban commuter expressways, peak-hour traffic congestion rises to meet maximum capacity”.

A considerable body of evidence is now available to confirm this. But, despite this indisputable fact, many road-improvement decisions continue to be based on the assumption that extra space will not generate new traffic.

If you build it, they will drive

A significant change occurred in 1994 when a report by the UK Advisory Committee on Trunk Road Appraisal confirmed road building actually generates more traffic.

In New Zealand, this wasn’t acknowledged until the Transport Agency’s 2010 Economic Evaluation Manual, which said:

[…] generated traffic often fills a significant portion (50–90%) of added urban roadway capacity.

Traffic increases as motorways expand.
Shaun Jeffers/Shutterstock

Some congestion discourages people from driving (suppresses latent demand), but with no congestion traffic will fill road space over time, particularly in or near urban areas.

Interestingly, the opposite can also work. Where road space is removed, demand can be suppressed and traffic reduces without other neighbouring roads becoming overly congested.

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One of the best examples of this is the closure of the Cheonggyecheon Freeway in the middle of Seoul, South Korea.

When the busy road was removed from the city, rather than the traffic moving to and congesting nearby roads, most of the traffic actually disappeared, as Professor Jeff Kenworthy from Curtin University’s Sustainable Policy Institute notes.

This suppression of latent demand works best when good alternative ways of travel are available, including high-quality public transport or separated cycle lanes.

The short answer to the question about road building and expansion is that new roads do little to reduce congestion, and they will usually result in increased emissions.

Simon Kingham, Professor, University of Canterbury

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Global bank urges cities to invest in new infrastructure to adapt to climate change

Our cities need to adapt to cope with more extreme weather events and other impacts from climate change.
Flickr/Shaun Johnston, CC BY-NC-ND

Elisa Palazzo, UNSW

The impacts of climate change on weather, sea levels, food and water supplies should be seen as an investment opportunity for our cities, says global investment banking firm Goldman Sachs.

In a report out last month the bank says cities need to adapt to become more resilient to climate change and this could “drive one of the largest infrastructure build-outs in history”.

The bank says cities will be on the frontline of any need to adapt because they are home to more than half the world’s population and generate roughly 80% of global GDP.

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The state of the debate

The report comes at a time when scepticism and wait-and-see approaches are still permeating the debate on climate action globally. The discussion on reducing emissions is dogged by disagreement on targets and actions to be undertaken.

Report cover.
Goldman Sachs

On the contrary, less emphasis has been placed on adapting to global warming, the consequences of which will play out for decades to come even if we meet the goals of the Intergovernmental Panel on Climate Change (IPCC).

Goldman Sachs has already said it acknowledges the scientific consensus that climate change is a reality and human activities are responsible for increasing concentrations of greenhouse gases in Earth’s atmosphere.

Much global attention has focused so far on the need for climate change mitigation and the reduction of CO₂ emissions. But the bank’s latest report addresses the urban adaptation strategies that are urgently required:

Greater resilience will likely require extensive urban planning, with investments in coastal protections, climate-resilient construction, more robust infrastructure, upgraded water and waste-management systems, energy resilience and stronger communications and transportation systems.

It acknowledges mitigation measures are essential to reduce global temperature in the medium and long term. But it argues we need to act immediately to minimise the current and future effects of climate change in urban areas.

The question is, why would a bank endorse such a vision?

Banking on climate change

The bank’s report is a collection of data and analysis on climate change from well-known sources, such as the IPCC, and a detailed list of expected impacts on cities.

For example, higher temperatures, more frequent and intense storms, and rising sea levels could affect economic activity, damage infrastructure and harm vulnerable residents.

Does the report represent a last call to brace for impact? Or is a more nuanced and somehow optimistic view of the process emerging?

In reality, it’s not surprising this call is coming from an international financial institution such as Golden Sachs. This report needs be read in parallel with the environmental policy framework of the bank which is its “commitment to addressing critical environmental issues”.

The latest report identifies urban adaptation responses and initiatives as market solutions and financial opportunities. It clearly points out where investments should be addressed.

The directions outlined range over infrastructural initiatives to measures that require financial investment. Our cities need better coastal protection, more resilient buildings and open spaces, sustainable water and waste management, and upgraded transport systems.

A call for action

There is a positive takeaway emerging from the bank’s viewpoint which is a pragmatic call for action.

This could reinstate a more optimistic view of climate change. It could overcome the wait-and-see approach by moving the discussions beyond mitigation only.

And the report has the merit to outline some major challenges emerging from the need of financing a comprehensive urban adaptation.

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Design for flooding: how cities can make room for water

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First, the need for innovative sources of financing and new ways to support climatic transition.

Secondly, the need to look at equity issues emerging from an adaptation process. For example, should a city strengthen flood defences in the CBD or should it upgrade public housing in flood-prone areas? Given the scale of the aims we need to evaluate carefully where best to invest the limited resources available.

But in this respect, no solutions are proposed.

This report is one of the many financial reports on climate change we have seen recently, about the risks and opportunities for the banking and insurance system. It’s probably the first to acknowledge clearly the need for comprehensive adaptation investments to make our cities more resilient.

But in concentrating on the infrastructure needs for cities, the report seems to miss the big picture.

There is still a need to understand how more integrated actions will include the social and environmental dimensions of adapting to climate change to create more sustainable and equitable cities.

Elisa Palazzo, Senior Lecturer, Faculty of Built Environment, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Billions spent on Murray-Darling water infrastructure: here’s the result

Q J Wang, University of Melbourne and Avril Horne, University of Melbourne

Earlier this year, researchers suggested the amount of water returned to the Murray Darling Basin under a federal program has been “grossly exaggerated”, to the tune of hundreds of billions of litres.

The report argued that government investment in irrigation improvements might even result in a net loss of water for the environment.

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The Darling River is simply not supposed to dry out, even in drought

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To investigate these claims, the Murray Darling Basin Authority commissioned us to undertake an independent review to examine the best available data for every irrigation efficiency project funded across the basin.

We found the government investment into irrigation efficiency projects has achieved 85% of the 750 gigalitres per year target. The remaining 15% of the target may be affected by unintended side-effects.

This result highlights the need for continued review of risks to the basin plan, as Australia grapples with the management of an extraordinary complex natural system.

How is water for the environment recovered?

The Water Act 2007 introduced significant reforms aimed at setting aside more water for the environment. At the time, record high levels of surface water were being consumed. Aiming to save 2,750 gigalitres of surface water (water flowing in the open air, rather than underground) the federal government began buying back water rights and investing in more efficient infrastructure.

The Commonwealth is providing A$3.1 billion to buy these water rights, of which A$2.5 billion has been spent. It is also providing more than A$8 billion for modernising infrastructure and water efficiency improvements, of which more than A$4 billion has so far been spent.

These projects aim to improve water delivery – reducing leaks and evaporation – and make irrigation more efficient. The water saving generated from these projects is shared between the governments for environmental use, and irrigators.

Mass fish deaths earlier in the year raised serious concerns about the health of the Murray-Darling system.
DEAN LEWINS/AAP

What are “return flows”?

To understand why the government investment in irrigation efficiency projects have not achieved 100% of the original target, we need to talk about return flows.

When water is diverted from the river for irrigation, not all of it gets consumed by the plants. Some water will make its way back to the river. This is called return flow. A large part of the return flow is through groundwater to the rivers, and this part is extremely difficult to measure. More efficient infrastructure and irrigation generally means less return flow to the river.

If these reductions are not considered when calculating the water savings, it is possible there will be implications for irrigators, the environment and other water users downstream, that previously benefited from return flows.

What we tried to determine is how much the efficiency projects reduced return flow.

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We wrote the report for the minister on fish deaths in the lower Darling – here’s why it could happen again

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Are the water savings real?

For the first time, we attempted to bring together data on individual projects in order to assess return flows across the basin. We developed a framework for calculating return flows, which took into account water in the rivers, groundwater, and efficiency projects.

This is the first attempt to bring together the existing data on individual projects to assess return flows in the basin at a detailed level. A large portion of the data used in this study was collated for the first time and not previously available in a readily accessible format.

We found a reduction in return flow of 121 gigalitres per year as a result of the government funded projects. This is comparable to 16% of the recovery transferred to environmental entitlements.

What does this mean for the Basin Plan?

There are several important details that must be considered to assess the importance of the return flow volume for the environment and Basin Plan objectives. We do not attempt here to quantify the outcomes, but instead to raise a number of important considerations beyond simply “volume”.

1. Recovered water should be legally protected

Return flows are good for the environment, but are essentially accidental. As irrigation becomes more efficient, inevitably they will diminish.

On the other hand, formally allocated environmental water entitlements are legally protected. It is more secure for the environment – and far easier to keep track of.

2. It’s not ‘efficiency vs the environment’

Part of this debate centres around the idea that reducing return flows means less water for the environment. But in Victoria and New South Wales, before water is allocated to anyone (irrigators or the environment), a base level is set aside. This is the minimum required to keep the rivers physically flowing and to meet critical human needs.

Efficiency projects mainly affect this base-level flow of the river. This means the water reduction is shared across everyone who holds a water licence – the majority of which are irrigators.

This policy means it does not make sense to compare the effect of efficiency projects directly with the recovery of environmental water.

3. Volume is a crude measure of environmental benefit

The focus of the debate around return flows has been based on the annual volume of returned environmental water in comparison to the stated Basin Plan target.

However, the real objective of the water recovery is to achieve environmental objectives in the Basin. This is not just about annual volumes, but the quantity, timing, and quality of fresh water.

How should we move forward?

Our review has particularly highlighted the need for better ongoing data collection and regular evaluations.

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Aboriginal voices are missing from the Murray-Darling Basin crisis

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Both taxpayer investments and the water market are changing irrigation to become more efficient and reducing the river’s base flow. With this in mind, we need to regularly reexamine how we share water between everyone (and everything) that needs it, particularly in extended dry periods.

The Murray-Darling Basin is a constantly changing system, both in terms of climate and irrigation. Return flows are one of a number of potential threats to the Basin Plan. As the system is continually changing, these threats will need to be reassessed with each Basin Plan review.

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A Four Corners program on the $13 billion Murray-Darling Basin Plan will air on ABC at 8.30pm on July 8.

This article was co-written by Glen Walker, a former CSIRO employee and now private consultant, who worked with the University of Melbourne on the independent review.

Q J Wang, Professor, University of Melbourne and Avril Horne, Research fellow, Department of Infrastructure Engineering, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Lessons from South Australia’s blackout: we need to make infrastructure more resilient to climate change

Mark Gibbs, Queensland University of Technology

Last week’s storm and subsequent state-wide blackout in South Australia reminds us how important the electricity grid – and other infrastructure – is for our communities.

Immediate analysis suggests the blackout was caused by the collapse of transmission infrastructure in South Australia. Australian electricity networks, like most transmission networks worldwide, rely on above-ground conducting wires held aloft by large towers. Some of these towers were blown over in the South Australian event.

While the storm hasn’t yet been specifically linked to climate change, it also serves as a reminder of the increasing challenges of delivering essential services in a more variable climate and slowing economy.

Power, water, transport, health, defence and communications infrastructure can be exposed to climate variability and change simply because of their long lifetimes. Therefore, many if not most owners and operators of essential infrastructure have commissioned climate vulnerability and adaptation studies.

There are many good examples of adaptation. For instance, Queensland Urban Utilities, the major water distributor and retailer in south-east Queensland, is implementing a large program to make the water and wastewater delivery network more resilient to flooding.

But there is increasing recognition among climate adaptation researchers that many of the recommendations from climate adaptation studies aren’t being adopted. This is sometimes referred to as the “plan and forget” approach to climate adaptation and it leaves critical infrastructure vulnerable to weather extremes.

Speaking different languages

One of the less obvious reasons for lack of uptake is the difference in language used in the climate science and adaptation community and in the infrastructure community.

All technical disciplines develop their own specialised language and climate science is no exception. But planning for climate change means that infrastructure professionals have to apply climate science to engineering planning and design.

Both disciplines use risk management as a common framework for assessing and managing risks. But the “bible” of climate science, the Intergovernmental Panel of Climate Change (IPCC) process, has invented new definitions of risk.

These differ from the long-standing definitions of risk enshrined by the International Organisation for Standardization and widely used by the engineering and infrastructure community.

Many engineers find they cannot use the IPCC reports and projections because this information cannot be directly integrated into planning and design processes that are often heavily regulated and prescribed.

By necessity, climate projections are based on probabilities that specified environmental conditions may occur.

By contrast, engineering design is often based on a specified extreme number, whether it be a maximum wind strength or flood height, rather than a set of probabilities.

Over time it is expected that engineering design methodologies will be able to assimilate climate projections, but updating these highly prescriptive standards can be a drawn-out process.

Harder, better, faster, stronger

Often the most common recommendations in infrastructure climate adaption studies are to make infrastructure stronger, higher and, by implication, heavier and more expensive. A common example is a recommendation that bridges be elevated and made stronger to account for expected higher flood levels and water flows.

While this is understandable, it is in stark contrast with the way almost all other products are being developed – lighter, faster, cheaper, smarter.

Australia is also consistently either at the top, or near the top, of the infrastructure cost league table. It’s one of the most expensive places to design and construct infrastructure worldwide.

Therefore, climate adaptation recommendations to make infrastructure more resilient through brute strength can be difficult to fund – although, in some cases, this may be the only viable option.

Getting creative

We need to think a little more creatively. A good starting point is to take the approach advocated in the relatively new international asset management standard called the ISO 55000 standard.

A key part of this standard is not to think about infrastructure assets in isolation, but to consider how each asset contributes to an essential service, such as providing electricity to our homes. After all, infrastructure assets are only constructed to deliver a service. It is the service that is key, not just the individual asset.

Importantly, the demand for services, levels of service and the way essential services will be delivered in future decades is all largely unknown. Technology will change how essential services are defined and delivered.

Distributed energy – such as rooftop solar – may reduce the need for extensive transmission networks. Smarter combinations of light rail and autonomous vehicles may change demand for major road infrastructure.

New water-treatment technology, such as within-pipe treatment, may do away with the need for large treatment plants that are often located in low-lying regions exposed to sea-level rise.

Climate adaptation needs to stop recommending that existing infrastructure just be built stronger and higher, and take a broader and smarter perspective of what infrastructure may be required as climate change increasingly makes its presence felt.

Mark Gibbs, Director: Knowledge to innovation. Chair: Green Cross Australia, Queensland University of Technology

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

How green is our infrastructure? Helping cities assess its value for long-term liveability

Roger Jones, Victoria University; Celeste Young, Victoria University, and John Symons, Victoria University

Australian cities score high in liveability awards. Melbourne has topped The Economist’s most liveable cities ranking five years in a row, with Adelaide, Sydney and Perth not far behind and Brisbane in the top 20. Australian cities rank well in other liveability surveys, too, if not so highly. Environment is one of the key factors that these surveys measure, but the data and methods being used are not very sophisticated.

Green infrastructure is a key contributor to these rankings. The networks of green and blue – taking in rivers and streams, parks, green wedges, gardens and tree-lined roads and rail – underpin urban liveability.

Yet, if we look at these valuable assets, they are mainly historical legacies of the 19th century. They include The Domain, Treasury-Fitzroy Gardens and Royal Park in Melbourne, Hyde and Centennial Parks in Sydney, King’s Park in Perth, the Adelaide Parklands and those in Brisbane, Hobart and Canberra.

Their creation was driven mainly by visions of what a city should look like and provide for its people. This was long before the invention of cost-benefit analysis and many of the other tools used to make the economic case for infrastructure.

Future-proofing urban environments

Today, if a key parcel of land is up for development, green infrastructure is often an afterthought, if considered at all. The recent reports that the former Victorian government rezoned Fishermans Bend, a former industrial site of 455 hectares, without proper regard for grey or green infrastructure are not unique.

In an area threatened by sea-level rise, increased flooding and heat island effects, to allow development that exacerbates these issues is extremely short-sighted.

But this is happening in many localities. Changing climate and the unintended consequences of small decisions, such as urban infilling, are making cities hotter, more prone to flash-flooding and less green.

Rain gardens have aesthetic and practical value as they reduce urban flooding by slowing water run-off.
shutterstock

Local government authorities are on the front line with these issues. They carry the major burden of responsibility for developing and maintaining neighbourhood environments. Over the last few years, some councils have considerably increased spending on park renewal, rain gardens to slow runoff, water capture and recycling and urban forest strategies.

However, this is occurring in an economic environment where local government’s resources are limited and efficiency is emphasised at every turn. State governments run on a platform of capping rates, not considering whether those rates reinvested by council generate ongoing socially beneficial returns.

When communities are asked what they want councils to invest in, green infrastructure is usually high on the list. Local government has recognised these pressures, identifying the need to build better business cases for green infrastructure projects and programs in order to justify their expenditure.

Finding better ways to value green assets

A recent collaborative project, involving four metropolitan Melbourne councils and Victoria University, has put together a framework to help local government identify the benefits of green infrastructure over its whole lifecycle.

The aim is to build better business cases to support projects and develop asset management programs for green infrastructure. This would lead to trees and parks being considered in a similar way to roads and buildings as assets that provide a stream of benefits to the community over their lifetimes.

Valuing the benefits of green infrastructure is tricky, though. This is because each element provides multiple benefits, which cover very different types of value.

For example, a wetland can provide flood protection, substitute for external water supply, cool an area, increase biodiversity, provide recreational opportunities and contribute to adjacent property value. These wetland benefits are public, private and intrinsic.

High-quality open space can contribute to people’s physical and mental health and wellbeing. This has the results of offsetting medical costs and promoting higher economic productivity and improved human welfare (happiness and satisfaction). Putting a dollar figure on all of these benefits is extremely complex.

The long-lived aspect of green infrastructure also means it can play a major role in adapting to changing climates within urban environments. The future value of flood protection, cooling services, amenity, recreation and human health and welfare can be substantial.

However, current methods of discounting future dollar benefits, at roughly 5% each year, undervalue these long-term benefits. A recently completed project in Melbourne’s west identified the potential for welfare and environmental benefits exceeding A$300 million over 30 years (discounting at 3.5%) by reducing pollution from an industrial precinct using integrated urban water management principles.

The framework is a starting point for councils to address the economic value of green infrastructure. It is different to most other frameworks, with the emphasis not being on how to select the type of infrastructure, but on how to get a project or program valued, approved and implemented. It has been tailored to existing council processes so it can be used now, but also grow as council programs evolve.

One major gap that our work has pointed out is the lack of available data in Australia to measure green infrastructure benefits with confidence. They are there, but it would be great to rate liveability with confidence and to have it on the same footing as income or GDP.

Roger Jones, Professorial Research Fellow, Victoria University; Celeste Young, Collaborative Research Fellow, Centre for Strategic Economic Studies, Victoria University, and John Symons, Research Fellow in the Victorian Institute for Strategic Economic Studies, Victoria University

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

Hunter Region Botanic Gardens

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ABOVE: The Southern Wetlands Boardwalk – Hunter Region Botanic Gardens

Late last week I decided I should do something with the final day of my annual leave that I had taken this time round, so I thought I’d pop into the Hunter Region Botanic Gardens near Raymond Terrace in New South Wales, Australia. I had been here before, but that was a long time ago. I wasn’t impressed on that first visit, so after more then a decade had it improved? Well that was the question I was keen to answer.

ABOVE: The Rotunda  BELOW: Succulents Section

There was a $4.00 ‘escape’ fee, which would allow a token to be purchased and then the boom gate would rise once it was placed into the proper slot at the exit. So no entrance fee, just an exit fee. I was willing to pay this for a quick look and…

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ELECTRIC CARS COMING SOONER RATHER THAN LATER

In great news for the environment and consumers it seems that ‘green cars’ will be arriving in Australia sooner rather than later, with infrastructure for electric cars to be set up in Brisbane, Sydney and Melbourne within four years. The project is a joint venture between AGL, Macquarie Capital and Better Place.

The project aims to set up recharge stations for electric cars at workplaces, homes and shopping centres. It is thought that some 250 000 recharge stations will be built in the project. Such projects have already been set up in Israel and Denmark.

Macquarie Capital is to raise $1 billion to build the recharging network, with AGL to supply renewable energy for the project. Better Place will actually build the network.

Should the project go ahead and the infrastructure be built, motorists will be able to dump petrol and diesel vehicles and move to electric ones. This will of course be a great relief from rising fuel costs and help protect the environment from further greenhouse gas emissions.