While national governments struggle to agree on climate action, many cities around the world are already taking vigorous steps to reduce their greenhouse gas emissions. Urban transport is one of the most important sectors for reducing emissions.
Canberra is at the forefront of this urban-oriented action on climate change.
The Capital Metro Light Rail project will be a transformative project for the Canberra-Queanbeyan urban area, bringing a wide range of economic, health, social and environmental benefits. Climate benefits can be added to that list.
Building on the ACT's rapid roll-out of renewable energy, the CMLR project will drive further significant reductions in greenhouse gas emissions, focusing on Canberra's transport sector.
A detailed analysis of the emission reductions that will be achieved by the CMLR, based on the first stage between the City and Gungahlin, shows the potential for major climate benefits. The numbers are impressive.
By 2020, when the first stage of the CMLR system is operational, about 2900 to 4700 tonnes of greenhouse gas emissions per year, measured in CO2-equivalents, will be eliminated from the transport sector. This translates to an 18-30 per cent emission reduction on the City-Gungahlin corridor in 2020 compared to the business-as-usual case with no light rail.
Even more impressive are the reductions on a per-passenger basis. For every passenger who switches from a private vehicle to the light rail, emissions for the trip will essentially be eliminated.
The reason for this elimination of per-passenger emissions is clear. The light rail cars are powered by electricity, not by fossil fuels that directly emit CO2 on combustion. By 2020, the ACT will be sourcing 90 per cent of its electricity from renewable energy systems such as solar and wind, Furthermore, the ACT Government has mandated that Capital Metro source the remaining 10 per cent of electricity from renewable sources, so the electricity powering the CMLR will be entirely free of greenhouse gas emissions.
The range of 18-30 per cent of emission reductions is based on estimates of the number of Canberrans who switch from private cars to light rail – that is, on the "modal shift". As shown by experience in the US, where modal shifts are commonly towards the upper end of the 20-30 per cent range when light rail is introduced, it is likely that the light rail here will also lead to modal shifts near the upper end of the range.
The analysis is conservative in other ways, and likely underestimates the climate benefits from the light rail project. For example, the analysis is based only on the City-Gungahlin corridor itself and does not include the modal shift from private vehicles to ACTION buses or to active transport – walking and cycling – on trips that feed into the light rail route.
The experience in the Gold Coast, where the new light rail line has both attracted more passengers than predicted and increased overall bus usage in the network, supports the assessment that our analysis is conservative.
The influence of the light rail system in triggering more compact development along the corridor will yield further emission reductions, depending of course on the quality and efficiency of the built infrastructure and the behavioural patterns of its occupants.
As the light rail network is extended beyond the City-Gungahlin stage to other transit corridors in the city and the number of passengers increases further, the climate benefits will grow even more.
In short, the light rail network will eventually become the backbone of a transformed transit system – integrated with ACTION bus routes, cycleways, walking corridors and electric vehicle charging stations – that delivers an efficient, resilient, carbon-free Canberra transit system, powered by renewable energy.
Following the positive outcome of the pivotal Paris climate change conference earlier this month, the urgency to deal effectively with the climate change challenge is apparent. Cities are in the frontline in tackling this challenge.
With its outstanding climate benefits added to the long list of other benefits, the CMLR project is an excellent investment in critical urban infrastructure. It places Canberra in a leading position to show the way in decarbonising both electricity generation and transport systems.
Will Steffen is adjunct professor at the University of Canberra and theme leader in CURF (Canberra Urban and Regional Futures)