From the 1940s, new technologies, like carbon dating, ice- and sea-core drilling, and pollen analysis not only vastly expanded time horizons in geophysical and climatological research, but also pinpointed past events on a newly historical timescale. Using natural proxy indicators, these studies brought to light a series of globally disruptive events in geological time, for example, volcanic eruptions of previously unknown scale and types that had also an impact on the Earth’s climate. The past became discrete. Knowing more about the past also meant knowing more about possible futures, given that some catastrophic events have occurred repeatedly or have become increasingly predictable with the help of computer modeling. This meant that scientists' claims about the future of the earth increasingly came to interfere with politics and with traditional economic planning. The paper argues that the “new” past has come to weigh in two ways on the present and the future. First, it dwarfed the human time scale, thus increasing the challenge of dealing with heterogeneous time scales. Second, prehistoric past events came to take on political significance. The deep past became part of political history, and thus of politics.