Re: It's Snowing!
You would need a very powerful microscope to spot the particle at the centre of a snowflake, and it's not pollution at all. It might be minute particles of sand or salt that has been lifted into the atmosphere when water has been skimmed off the surface of the oceans or deserts by extreme weather.
Observe the particles on your vehicle after some rainfall, usually sand from the Sahara. Volcanoes also project small and large particles into the atmosphere, the large ones fall quickly, but the smaller ones can circulate the earth. Remember the Volcano in Iceland that caused all the problems?
And what about this.....
By 25 August, the Krakatoa eruptions intensified. At about 1:00 pm on 26 August, the volcano went into its paroxysmal phase. By 2:00 pm, a black cloud of ash could be seen 27 kilometres high. At this point, the eruption was virtually continuous and explosions could be heard every ten minutes or so. Ships within 20 km (12 mi) of the volcano reported heavy ash fall, with pieces of hot pumice up to 10 cm (4 in) in diameter landing on their decks. Between 7:00 pm and 8:00 pm, a small tsunami hit the shores of Java and Sumatra, some 40 km (25 mi) away.
On 27 August, there were four enormous explosions that occurred, which marked the climax of the eruption. At 5:30 am, the first explosion was at Perboewatan, triggering a tsunami heading straight to Telok Betong, now known as Bandar Lampung. At 6:44 am, Krakatoa exploded again at Danan, with the resulting tsunami stretching eastward and westward. The third and largest explosion, at 10:02 am, was so violent that it was heard 3,110 km (1,930 mi) away in Perth, Western Australia and the Indian Ocean island of Rodrigues near Mauritius, 4,800 km (3,000 mi) away, where the blast was thought to have been cannon fire from a nearby ship. The third explosion has been reported as the loudest sound heard in historic times.:79 The loudness of the blast heard 160 km (100 mi) from the volcano has been calculated to have been 180 dB. It is said[by whom?] that if anybody were to stand 10 miles (16 kilometres) away from the volcano's eruption, they would have gone deaf. Each explosion was accompanied by tsunamis estimated to have been over 30 meters (98 feet) high in places. A large area of the Sunda Strait and a number of places on the Sumatran coast were affected by pyroclastic flows from the volcano. The energy released from the explosion has been estimated to be equal to about 200 megatonnes of TNT (840 petajoules), roughly four times as powerful as the Tsar Bomba, the most powerful thermonuclear weapon ever detonated. At 10:41 am, a landslide tore off half of Rakata volcano, along with the remainder of the island to the north of Rakata, causing the final explosion.
The pressure wave generated by the colossal third explosion radiated out from Krakatoa at 1,086 km/h (675 mph), 90% of the speed of sound. The eruption is estimated to have reached 310 dB, loud enough to be heard clearly 5,000 kilometres (3,100 mi) away.:248 It was so powerful that it ruptured the eardrums of sailors 64 km (40 miles) away on ships in the Sunda Strait,:235 and caused a spike of more than 8.5 kilopascals (2.5 inHg) in pressure gauges 160 km (100 miles) away, attached to gasometers in the Batavia gasworks, sending them off the scale.[note 1]
The pressure wave was recorded on barographs all over the world. Several barographs recorded the wave seven times over the course of five days: four times with the wave travelling away from the volcano to its antipodal point, and three times travelling back to the volcano.:63 Hence, the wave rounded the globe three and a half times. Ash was propelled to an estimated height of 80 km (50 mi).
The eruptions diminished rapidly after that point, and by the morning of 28 August, Krakatoa was silent. Small eruptions, mostly of mud, continued into October 1883. By then, less than 30% of the original island remained.
Compared to that, we don't know what pollution is.....