see url:
https://www.climate.gov/news-features/climate-qa/whats-hottest-earths-ever-been
see full article...If you think it aint half hot mum...then read the
full article for a bit more knowledge about how hot the planet has
gotten in its history....Long before human beings got around to playing
on it and at it...Two swallows don't make a summer...and whilst human
activity may be having some influence on the planets climate, there are
far larger and longer term forces at work, all of them outside of human
control; such as changes in the Earth's spin, gravitational forces, the
Sun and Sunspots, the Solar Wind...volcanic eruptions, earthquakes to
name but a few.
In my view, it is a good idea to become more aware of these changes,
increasing our knowledge of our planet and the universe; and it is a
good idea for the preservation of the species to try not to pollute the
planet as much as possible and to find and use ecological sources of
energy and become more efficient in using those sources...but as for
human beings changing the world...We have a long way to go yet...Mind
you...the way the military technology is going, we might just get round
to blowing up the planet altogether in attempts to resolve international
conflicts between nation states...such is the contrariness of human
nature and folly...đ Still, the human species is only about 5 million
years old, and many species have come and gone on planet earth during
its 5 billion year existence, so us humans are but little specs on the
planetary landscape in terms of both size and time...and the planet
doesn't owe us a living...We have to go or change sometime, its the
consequence of evolution
Quote<<<
This article was first published in August 2014, and it has been updated
to include new research published since then. This article is one of a
two-part series on past temperatures, including how warm the Earth has
been âlately.â
Our 4.54-billion-year-old planet probably experienced its hottest
temperatures in its earliest days, when it was still colliding with
other rocky debris (planetesimals) careening around the solar system.
The heat of these collisions would have kept Earth molten, with
top-of-the-atmosphere temperatures upward of 3,600° Fahrenheit.
Even after those first scorching millennia, however, the planet has
often been much warmer than it is now. One of the warmest times was
during the geologic period known as the Neoproterozoic, between 600 and
800 million years ago. Conditions were also frequently sweltering
between 500 million and 250 million years ago. And within the last 100
million years, two major heat spikes occurred: the Cretaceous Hot
Greenhouse (about 92 million years ago), and the Paleocene-Eocene
Thermal Maximum (about 56 million years ago).
Cartoon by Emily Greenhalgh, NOAA Climate.gov.
History of hot
Temperature records from thermometers and weather stations exist only
for a tiny portion of our planet's 4.54-billion-year-long life. By
studying indirect cluesâthe chemical and structural signatures of rocks,
fossils, and crystals, ocean sediments, fossilized reefs, tree rings,
and ice coresâhowever, scientists can infer past temperatures.
None of these techniques help with the very early Earth. During the time
known as the Hadean (yes, because it was like Hades), Earthâs collisions
with other large planetesimals in our young solar systemâincluding a
Mars-sized one whose impact with Earth likely created the Moonâwould
have melted and vaporized most rock at the surface. Because no rocks on
Earth have survived from so long ago, scientists have estimated early
Earth conditions based on observations of the Moon and on astronomical
models. Following the collision that spawned the Moon, the planet was
estimated to have been around 2,300 Kelvin (3,680°F).
What the collision that spawned Earth's Moon may have looked like.
Collisions between Earth and rocky debris in the early solar system
would have kept the surface molten and surface temperatures blistering.
Image courtesy NASA.
Even after collisions stopped, and the planet had tens of millions of
years to cool, surface temperatures were likely more than 400°
Fahrenheit. Zircon crystals from Australia, only about 150 million years
younger than the Earth itself, hint that our planet may have cooled
faster than scientists previously thought. Still, in its infancy, Earth
would have experienced temperatures far higher than we humans could
possibly survive.
But suppose we exclude the violent and scorching years when Earth first
formed. When else has Earthâs surface sweltered?
Thawing the freezer
Between 600 and 800 million years agoâa period of time geologists call
the Neoproterozoicâevidence suggests the Earth underwent an ice age so
cold that ice sheets not only capped the polar latitudes, but may have
extended all the way to sea level near the equator. Reflecting ever more
sunlight back into space as they expanded, the ice sheets cooled the
climate and reinforced their own growth. Obviously, the Earth didnât
remain stuck in the freezer, so how did the planet thaw?
>>>End of Quote
