Timeblog.net

TreeHugger discusses an important topic. Carbon dioxide certainly is the most important contributor to the artifical greenhouse effect leading to global warming, especially since the amount of carbon dioxide dramatically increases (compared e.g. to methane). But it is irresponsible to reduce global warming merely to carbon dioxide.
So-called “black carbone”, that is carbon particles from soot resulting from burning processes may account for up to 16% of global warming, as it absorbs sunlight and transmitting infrared radiation (heat radiation). This is the same process that is responsible for earth being inhabitable, as normally the sun rays reach the planet’s surface, and in process the earth surface radiates in the infrared spectrum. The infrared radiation gets “trapped” by the gases in the atmosphere while the sun rays of much smaller wavelengths were able to pass through, much like the effect in a greenhouse where the glass allows visible light to pass but reflects infrared radiation back. Without this (natural) greenhouse effect, the temperature on the earth’s surface would be below the freezing point of water (if you use the Stefan-Boltzmann law and estimate albedo effects, earth would have like 255K only, compared to 288K actual global average temperature). But, the artifical contribution by mankind that increases the amount of greenhouse gases, that is gases reflecting infrared radiation like carbon dioxide, leads to increasing temperature.
For the black carbon, the infrared radiation is radiated straight into the atmosphere. Diesel-engines seem to produce a disproportiate amount of soot. This has also major health-related consequences. In Germany at least, this has lead to great discussion, resulting in the promotion of fine particle filters and to (very inconsequent, bureaucratically overburdened and locally confined) future bannings of cars that emit too much fine particles from driving in cities.