OCR Text |
Show Chsnges of Climate. A scientist who recently Investigated 'ho causes of secular variations In temperature tem-perature at the earth's surface thinks that they sre more probably due to changes In the amount of carbonic rid In the atmosphere than to variations varia-tions In the heat ot the sun. If the amount of carbonic acid that the atr now contains was diminished a little nore than half, the mean temperature ill over the earth would, it Is stated, rp about eight degrees, which would be sufficient to bring on another gla-Si gla-Si I period. On the other hand, an in-.-ruse of carbonic acid to between two snd three times tls present amount enuld raise the mean temperature IS d rrces and renew the hot times of til'? Eorrne epoch. |