the planet has existed for millions of years
Er, the planet has existed for 4.5 BILLION years. There have been at least 5 major ice ages in geological history. The last one was from 110,000 to 12,000 years ago. We are currently in the early stages of an inter-glaciation period.
The period of contemporary scientific research and record-keeping, as correctly pointed out, at about 150 years, represents about the last 0.000003% of planetary existence. If the existence of the earth were represented by the 1281 pages of the bible, the period of contemporary scientific research and record-keeping would be represented by less than the single last letter of the last word on the last page of the bible.