Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cars Warm Up, Ships Cool Down

25.01.2008
Road traffic is by large the transport sector that contributes the most to global warming. Aviation has the second largest warming effect, while shipping has a net cooling effect on the earth’s climate, according to a study published recently.

The study, “Climate forcing from the transport sectors”, is the first comprehensive analysis of the climate effect from the transport sector as a whole on a global scale. Breaking down the transport sector to four subsectors: road transport, aviation, rail, and shipping, five researchers at CICERO have calculated each subsector’s contribution to global warming. The researchers have looked at the radiative forcing (RF) caused by transport emissions. The RF describes the warming effect in the unit Watt per square meter (W/m2).

The study that was published in the prestigious publication, Proceedings of the National Academy of Sciences (PNAS), concludes that since preindustrial times, 15% of the RF caused by man-made CO2-emissions have come from the transport sector. The study also looks at other emissions. For ozon (O3), transport can be blamed for ca 30% of the forcing caused by man-made emissions.

The study implies that more attention needs to be put on the fast growing road sector. Looking solely at CO2 emissions, road traffic alone has led to two-thirds of the warming caused by total transport emissions (this is using a historical perspective looking at emissions since pre-industrial times.)

Including all gasses, not just CO2, and looking at the effect today’s road emissions has on future climate, the share is even larger: the road emissions of today will constitute three- fourth of the warming caused by transport over the next hundred years.

For shipping, the picture is more complicated. Until today, shipping has had a cooling effect on climate. This is because shipping emits large portions of the gasses SO2 and NOx, which both have cooling effects. However, although these two gases, until now, have given the shipping industry a cooling effect, this effect will diminish after a while, as the gases don’t live long in the atmosphere. After a few decades, the long-lived CO2 will dominate, giving shipping a warming effect in the long run.

The net cooling effect from shipping does not imply that shipping emissions don’t need to be cut back on. Both SO2 and NOx have other impacts that damage the environment.

A remark can be made here saying that SO2 and NOx are not covered by the Kyoto Protocol; neither is black carbon (soot). Therefore, the Protocol is too narrow to capture the real climate effect of transport emissions, particularly for the shipping sector.

Following road transport, aviation is the second largest transport contributor to global warming. The reason that road transport tops the list is mainly the amount of vehicles on the roads and the smaller cooling effect from their emissions. The researchers have not yet looked at emissions per kilometre or per person at a certain distance using different transport modes.

Also, aviation has a strong contribution to global warming. However, the historical contribution from aviation emissions to global warming is more than doubled by the contribution from road emissions. Over the next 100 years, today’s road emissions will have a climate effect that is four times higher than the climate effect from today’s aviation emissions.

The warming effect by rail emissions is very small, almost not noticable at all, compared to the effects from road transport and aviation.

In general, the transport sector’s contribution to global warming will be continously high in the future. The current emissions from transport are responsible for approximately 16% of the net radiative forcing over the next 100 years. The dominating contributor to this warming is CO2, followed by tropospheric O3.

Reference:
Jan Fuglestvedt, Terje Berntsen, Gunnar Myhre, Kristin Rypdal, and Ragnhild Bieltvedt Skeie. "Climate Forcing from the Transport Sectors", PNAS 10.1073/pnas.0702958104, 7 January 2008.

Petter Haugneland | alfa
Further information:
http://www.cicero.uio.no/webnews/index_e.aspx?id=10931

More articles from Studies and Analyses:

nachricht Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Oxygen loss in the coastal Baltic Sea is “unprecedentedly severe”
05.07.2018 | European Geosciences Union

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>