Steampunk - Wikipedia
Global cooling was a conjecture , especially during the s, of imminent cooling of the Earth culminating in a period of extensive glaciation , due to the cooling effects of aerosols and orbital forcing. Some press reports in the s speculated about continued cooling; these did not accurately reflect the scientific literature of the time, which was generally more concerned with warming from an enhanced greenhouse effect. Although the global temperature series available at the time suggested that the temperature had decreased for several decades up to the mids, as additional data became available through time, the global temperature series demonstrated significant increases over the next decades, which falsified the conjecture. By the s, scientists were becoming increasingly aware that estimates of global temperatures showed cooling since , as well as the possibility of large scale warming due to emissions of greenhouse gases. Paul R. Ehrlich mentioned global warming from greenhouse gases as a counterforce to the cooling effect of aerosols in Currently, there are some concerns about the possible regional cooling effects of a slowdown or shutdown of thermohaline circulation , which might be provoked by an increase of fresh water mixing into the North Atlantic due to glacial melting.
There have been five or six major ice ages in the history of Earth over the past 3 billion years. The Late Cenozoic Ice Age began 34 million years ago, its latest phase being the Quaternary glaciation , in progress since 2. Within ice ages, there exist periods of more severe glacial conditions and more temperate conditions, referred to as glacial periods and interglacial periods , respectively.
Hartman with a , year time line There have been many ice ages. Ice, in fact, is far more common on planet Earth than warming. We are, in fact, lucky when we are living while the planet is warm.