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To what extent should we reduce CO2 emissions from cars?

Gregory Launay - Last update: January 20th, 2013


First: the regulations

From automakers point of view, constraint to reduce CO2 emissions is expressed mainly by government pressure. Up to now, t
his pressure has been expressed by negotiated
targets. In the European Union, for example, this has resulted in a "voluntary commitment" from automakers to achieve 140 grams of CO2 emissions per kilometer on average vehicle sold in 2008.

Facing the partial failure of this policy (the result achieved was 153 grams of CO2 per kilometer), it is now binding regulations that are implemented.

Average CO2 emissions (g / km) in 2008 - Source: ACEA

The European Union, it always has in 2009 adopted binding regulations applicable from 2012, which requires an average of 130 grams of CO2 per kilometer (with some subtleties, but hey ...).

Japan has a policy similar to the European Union and President Obama has decided that the United States will return soon rank with very ambitious targets of 35.5 mpg (read "miles per gallon") about 157 grams of CO2 per kilometer for 2016. This may seem lax compared to the European continent, but the U.S. so far from that goal is already very ambitious (this equates to a 21% decrease in the average passenger car in the U.S. in 2008 was 200 grams of CO2 per kilometer)!

History and emissions regulations in Europe - Source: Association of T & E, Final Report 2009

In this graph we see the effort made by European manufacturers for over ten years, but also the failure of the voluntary (green points above which it would have had to spend). We also track the curves followed by Korean (KAMA) and Japan (JAMA).

These regulations relate to cars. Similar constraints for light commercial vehicles are being developed in the United States and the European Union.

Emerging countries are also there and we start to see a convergence towards a profiler regulation to 100 grams of CO2 per kilometer (~ 55mpg) in 2020.

Regulation of CO2 emissions from passenger cars - Source: International Council on Clean Transportation, 07/2008

And physical restraint in all this?

Very good very good ... but what is the effect of these regulations on global CO2 emissions?

Physical restraint is described by the IPCC (Intergovernmental Panel on Climate Change Expert, IPCC English) in different ways depending on the limits that are considered "acceptable" in terms of global warming.

That used by governments within the "Climate Convention" of the UN (United Nations) to discuss international agreements is a halving CO2 emissions of fossil sources by 2050 compared to the 1990 baseline. This is what we call the 450 scenario (because it corresponds to a stabilization of CO2 concentrations at 450 parts per million) that would limit global warming to 2 ° C.

CO2 emissions from fossil origin - Various sources cited in the document

CO2 emissions in 1990 were about 22 Giga tonnes of CO2. The overall objective in 2050 is about 11 Giga tonnes ... we are now more than 30! The subject is therefore divided by three CO2 emissions, transport understood from now on.

Assuming a population of 9 billion people in 2050, it sets the threshold emission per person per year to 1.2 tons (1.7 if the population stabilizes at 6.5 billion people).

Fossil CO2 emissions per capita - Source: via IEA MEDAD 2009, 2006 figures

Emissions is still very unevenly distributed throughout the world does not make the same effort. For France, this halving the global scale (with reference to 1990) corresponds to a division by 4 where the famous "Factor 4" for us. In the United States it is more a factor of 10 ... There is work and it is far from being won ...

For my car, it would what?

Resume. For the automotive respect this constraint must therefore divide the CO2 emissions of the entire fleet by 3 in 2050 ... but with a fleet that is expected to double by then!

Considering that the average distance traveled by each vehicle is constant, we would therefore average consumption divided by 6 compared to today.

The current fleet average emits 225 grams of CO2 per kilometer. If we divide by 6 gives average emissions of 37.5 grams of CO2 per kilometer by 2050 (or about 1.6 liters per 100 kilometers, or 145 mpg). The average age of cars in the world is probably more than 10 years, it would require that the average CO2 emissions of new vehicles sold is about 40 grams of CO2 in 2040.

This objective is it just technically possible to achieve? The regulatory changes it is the right pace?