- Human population which has increased from approximately 1.6 billion to over 6 billion.
During the past century, carbon dioxide levels in the atmosphere has risen from 290 parts per million to nearly 370 ppm.
The 1990’s was the warmest decade in the past 140 years, with 1998 being the warmest year on record.
Nov. 1950- Severe storm event produces blizzard and severe winds in 22 states.
Droughts in mid-1950s in western US motivate intense period of dam-building for water storage and delivery. Image from NOAA Photo Library.