Sulfur dioxide, SO2, is not a greenhouse gas. But it should not be ignored when discussing climate. We know that the SO2 injected into the stratosphere by large volcanoes such as Agung, El Chichon, and Pinatubo, can cause cooling for a period of years. This is because of the reflective haze created by SO2 combining with water vapor to create sulphuric acid aerosol that then takes two or three years to fall down to altitudes where they find enough water vapor to grow, form clouds, and rain out.
We know that SO2 from industry and fossil fueled power plants form smogs and low clouds that produce acid rain down wind from the sources. We know what damage acid rain can do when the acid content is high enough to harm plant life. But little attention has been paid to the climate effects of the smogs themselves.
We know that low clouds and fogs keep surface temperatures from falling at night, as well as keeping surface temperatures from rising during daylight.
We know that in the polar regions in winter it is night all the time.
Now put those things together. In the Arctic, in winter, smogs and low clouds caused by SO2 will trap heat below them 24 hours a day, and in the spring will prevent sunlight from reaching and warming the surface. On the Arctic Ocean, this will delay both freezing in the winter and melting in the spring.
Figure 1: NORSEX ice extent for the last five years plus 2012 to date.
We can see clearly that the freeze-up in the Arctic has been delayed in recent years compared to the 1979 to 2006 average. Because the freeze-up is delayed, there is less ice to thaw in the spring, so that delay is less obvious, except that the ice minimum is also delayed compared to the average. Now we get to why? First, we look at two temperature anomaly maps of the Arctic.
Figure 2a and 2b: Temperature anomaly maps from Climate4You of the Arctic for all of 2011 and March of 2012. Note the location of the warming.
Now another map. This is a map of northern Russia.
Figure 3: Google map of northern Russia. The indicator on the map is the location of Norilsk.
Norilsk is the location of the world’s largest nickel mine. They also recover copper, cobalt, platinum, and palladium. Nearby, coal is mined to support the power needs of the city (130,000 population), the mine, and the smelter operations. SO2 emissions are about one million metric tons per year. This one location is responsible for 1% of all the SO2 emissions in the world, 10% of all of Europe’s emissions.
CNN reports that there is not a single living tree within 48 kilometers (30 miles) of the nickel smelter. 2,832 square kilometers (1093 square miles) of forest have been killed, and another 5371 square kilometers (2073 square miles) have been damaged. For a full report on the damage read this pdf document.
Norilsk Mining has other smelters on the Kola Peninsula very close to the Norwegian border. They also emit large amounts of SO2. Both locations are well above the Arctic Circle. All these emissions are within a very sensitive part of the Earth: the Arctic.
During the winter, the winds in the Arctic are variable, depending on the position of the Arctic front. The winds alternate between blowing to and from the land, moving any pollution over the Arctic Ocean or inland. In Figure 2b, in March,
the pollution from Norilsk was moving over the ocean much of the time. You can see the ebb and flow of the winds as they moved the sea ice in an animation of the last year here (from NRL).
Normally, SO2 is not a greenhouse gas, but it is in the dark of winter in the Arctic. In combination with water vapor, which is a greenhouse gas, it produces smog and low clouds that reflect heat back to the surface when it is dark, and upward into space when the sun shines. This distorts the melting and freezing patterns resulting in less ice in the Arctic Ocean. Yes, the reduction in ice in the Arctic is anthropogenic, with a Russian accent.
One thing people don’t know is that the platinum/palladium used in in automotive catalytic converters comes from Norilsk. We are simply moving the pollution from a distributed source, automobiles, to a concentrated source in Siberia. We are all responsible for Arctic warming.
Postscript: Norilsk Mining plans to reduce SO2 emissions by two-thirds as soon as they develop the necessary technology. They think this can be done by 2015 or 2020. Just in time for the general global cooling.