When it comes to reducing emission from light-duty vehicles (LDV), researchers in the US have shown that technology alone is not the solution.

In a paper published in Environmental Research Letters (ERL), Jalel Sager and colleagues from the University of California show that to meet greenhouse-gas emission and climate-reduction goals for the year 2050, the way in which we use LDVs has to change.

Co-author Daniel Kammen told environmentalresearchweb: "Reducing LDV emissions is often thought of as a technological challenge, with efforts going into the development of more efficient cars or fuels that produce fewer greenhouse gases per unit energy. However, by decomposing transport-sector emissions into technological and behavioural drivers, we show that even significant technological advances will be insufficient to meet climate goals, unless the growth in LDV use slows or reverses."

To quantify the carbon dioxide mitigation challenge for the transport sector, the researchers surveyed 2007 LDV usage and fuel economy in an economically diverse set of countries. They found that the large differences in per capita LDV greenhouse-gas emissions (range: ˜100–4000 kg of carbon dioxide equivalent per year) are principally explained by differing national per_capita LDV use (range: 300–13,000 vehicle kilometres travelled (VKT) per year), rather than to fleet average fuel-efficiency and carbon-intensity factors, which reflect the broadly similar car technology worldwide.

The Green Car Congress is covering RAEL's recent research:

A team from the University of California, Berkeley concludes that reducing demand for light-duty vehicle (LDV) travel will likely be essential to meeting the international greenhouse gas emission and climate targets for the year 2050. Their open access paper is published in the IOP journal Environmental Research Letters.

Average per capita light-duty vehicle (LDV) transport CO2 emissions (kg CO2 person-1 yr-1) for a global sample of countries (2007) with a wide range of per capita incomes. Per capita transport CO2 emissions are decomposed into the product of two terms: per capita LDV use (horizontal axis, veh-km person-1 yr-1) and propulsion carbon intensity (vertical axis, g CO2 veh-km-1). Full explanation at Sager et al.

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