Today’s Antarctic region once as hot as California, Florida

http://news.yale.edu/2014/04/21/today-s-antarctic-region-once-hot-california-florida

by edj • 12 years ago

39 14 12 years ago

news.yale.edu

synctext• 12 years ago

PNAS paper: http://www.pnas.org/content/early/2014/04/16/1321441111.abst...

Yale promo: temperatures in parts of Antarctica reached as high as 17 degrees Celsius (63F) during the Eocene, with an average of 14 degrees Celsius (57F) — similar to the average annual temperature off the coast of California today.

PNAS abstract: Here, we present multiproxy data from Seymour Island, near the Antarctic Peninsula, that provides well-constrained evidence for annual SSTs of 10–17 °C (1σ SD) during the middle and late Eocene.

JoeAltmaier• 12 years ago

Where was Antarctica during the Eocene? Was it then parked over the South Pole?

phaemon• 12 years ago

Yes. Apparently Earth looked something like:

http://www.nature.nps.gov/geology/usgsnps/pltec/sc50ma.html

tokenadult• 12 years ago

A Google search "Eocene epoch continents" brings up pages suggesting Antarctica's location then was similar to its location now. Thank you for asking that interesting question, as I remembered that in earlier deep geologic time, Antarctica was much nearer to the equator.

cmsmith• 12 years ago

Missing from this press release, though not from the journal paper, is the unstable effect of ocean currents on water temperatures. The fact that the oceans have a straight shot around Antarctica at the moment generates a huge ocean current which blocks water from warmer latitudes making it south. Antarctica and South America were connected as recently as 30 MYa, blocking the circumpolar current and allowing water in the southern oceans to be much more mixed.

NAFV_P• 12 years ago

I was thinking that hurricane type storms would have been even worse 50m years ago.

jofer2• 12 years ago

It's also worth putting this in a bit of geologic perspective. The article mentions this, but doesn't explain it.

The Eocene is just before the earth went into a period of "icehouse" climate (that's still going on). During the part of the Eocene this article refers to, the earth was in a "greenhouse" phase, and global temperatures were much warmer than they've been any time since.

At that time (and throughout the majority of Earth's history), there likely weren't any significant ice caps on the planet.

On very long timescales, the Earth goes through periods of icehouse and greenhouse climates. We're currently in an "interglacial" within a period of icehouse climate that has persisted since the late Eocene. Most of Earth's history is dominated by long phases of greenhouse climate. During these, the global climate is more stable and much warmer. We don't have ice ages, and there probably aren't any ice caps at the poles.

The last period of icehouse climate began just after this, in the late Eocene. (Again, the "ice ages" you hear about are glacials and interglacials within a period of icehouse climate.)

Also, as other folks have mentioned, the Eocene is relatively recent, and Antarctica was essentially in its present-day position (the coals and other "warm-weather" rocks in Antarctica date from much earlier when it was near the equator).

Regardless, it is quite interesting that sea surface temperatures were as warm as this evidence shows! I just wanted to put this into a bit of perspective.

*Caveat to all of this: I'm a geologist and not a climatologist.

sologoub• 12 years ago

That's exactly the detail missing from this article!

The other bit of information that I would really find useful as a lay person is how temperature distribution varied during the "greenhouse" climates. For example, was it linear to todays differential, implying that if I can directly apply an increase of 20C to today's temp and say that the avg. CA temp would be 34C from the 14C referenced currently or is it more even and the jump at extremes will be significantly larger or smaller than at equator?

jofer2• 12 years ago

It's probably very spatially variable, but beyond that, I'm out of my depth.

Ocean circulation plays a large role in regional (and global) variations in climate. If nothing else, the changes in the shape of the ocean basins over time would result in very different regional climate patterns, even if the average global temperature stayed the same.

On top of that, changes in average global temperature tend to vary strongly by latitude, if I remember correctly.

argumentum• 12 years ago

Most of Earth's history is dominated by long phases of greenhouse climate. During these, the global climate is more stable and much warmer.

Shouldn't we welcome this? Lost in the debate about climate change is the question of whether or not the earth would be better off much warmer. Obviously there are costs to such change, but there are clearly benefits.

A lot of earth's land is tied up in uninhabitable frigid places. The idea that we should not slow or even intentionally accelerate global warming is not a completely nonsensical one.

dragop2• 12 years ago

It's a problem of how fast. If the Earth's climate slowly changed over thousands of years, we could probably adapt. Fast climatic changes would be a problem as the biosphere would take time to adapt. For example, remove all the ice from Antarctica (and ignoring most of it is currently below sea level and needs to rebound). You'd have a rocky landscape with no soil. Not very useful for growing crops.

frandroid• 12 years ago

Why do they say "today's" Antarctic region? That just makes the whole headline confusing. The Antarctic was probably in the same location then, so let's just remove the word Today, and now it's way clearer.

Come on, give me that bloody headline writing job already!!

Today’s Antarctic region once as hot as California, Florida

Related Stories