This Earth World's climate has gets changed shifted throughout history past. Ju lastfinal 650,000 years periods there have let been existed seven cycles bikes of glacialicy advance retreat country progress and retreat country, with the this abruptsharp endending of thethis last ice age about 7,000 years ago marking the beginning of the modern climate era — and of human civilization. Most of these climate changes are attributed to very small variations in Earth ’ s orbit that change the amount of solar energy our planet receives.
