One method of explanation is that once the past changes, so do the memories of all observers.

The current increase in greenhouse gases, he continued, is similar to past natural changes that profoundly altered the world.

Your list of our past changes is correct, but I judge these horses to be more important.

Archaeological evidence, oral history and historical documents can offer insights into past changes in the climate.

Models have been successfully employed to reproduce past changes in our climate.

Would better remembering their own past change Americans' willingness (grudging at best) to intervene?

"What you know about the past changes," the historian said.

To do this accurately obviously requires detailed knowledge of what these past changes were.

There have also been several extinction events coupled with the past changes in climate you are referencing.

It means that the current movement of the index will reflect past changes in dwelling prices and interest rates.