Part of a Large Number for a Lower Number

I took part today in the International Day of Climate Action organized by 350.org. This is a campaign to get the world's governments to agree on strong measures to bring the global atmospheric carbon dioxide concentration down to 350 parts per million, believed by environmental scientists to be the maximum level consistent with climate stability (the current level is 390 ppm). The Philadelphia action consisted of a couple hundred people gathering in the rain on Independence Mall to form the numeral "350," and having our picture taken by people standing on top of the Bourse building across the street (I think it's something like ten stories). Our photos don't seem to be available yet, but you can see those from dozens of other locations by going to their website. The weather always seems to be raw when I come to the Mall below Market Street for a demonstration. It was also raining during the National Equality Rally back in June.