JoNova

A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).


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Hottest summers in the last 2000 years were during Roman times

There’s a reason the Romans wore Togas

A new study near Sicily shows the sea surface temperatures were a whole two degrees Celsius warmer then. The worst-case scenario of the Paris Agreement has already happened, and it was nearly 2,000 years ago. And instead of being a baked-earth apocalypse, the Roman empire flourished during the warmth and declined as it cooled.

Time to burn oil and Make Rome Great Again?

The expansion of the Roman Empire coincided with the warmest period in the Mediterranean of the last 2,000 years.

Probably just a coincidence. /

A formanifera with the awkward name of Globigerinoides ruber apparently likes to live near the sea surface around 10 to 50 m down. Depending on the temperature, it ends up with slightly different ratios of calcium and magnesium. At some point it dies, sinks and sits in a mud layer on the sea floor 475m below. Eventually, for this lucky mud, someone digs it out and analyses it. This new study suggests the Mediteranean warmed up during Roman times from AD 1 to AD 500.

This was the Roman Climatic Optimum — an era we are spending trillions to avoid.

The researchers suggest that cooling and [...]

Denying 2000 years of the Medieval Warm Period, Little Ice Age on every continent

Here we go again. For five or so years believers didn’t really mention the Medieval Warm Period. Too bruised by the embarrassment of Hockey Stick Zombie failures. But it’s an inconvenient era they have to rub out because none of the expert models can explain what caused it, and it’s hard to panic about same temperatures that Edward the Confessor survived with oxen and carts.

And it’s hard to call the modern warmth “man-made” if nature created something just like it 1,000 years ago.

Climate change: We haven’t experienced anything like this in the past 2,000 years

By Michael Collett, ABC, Environmental Copy and Paste Promoter

Climate scientists writing in the journal Nature have found there is no evidence for “globally coherent warm and cold periods” over the past 2,000 years prior to industrialisation.

That’s significant, because climate change deniers have sometimes pointed to epochs like the so-called “Little Ice Age” or “Medieval Warm Period” to argue that the current global warming is one among multiple similar global climate events.

But what the research actually shows is that other “peak warming and cooling events” over the past two millennia appear to have [...]

Melting glacier in Alaska reveals ancient remains of forest – evidence of warm periods

Glaciers that tore trees in half and then froze the stumps are receding again in Alaska to reveal those old remnants of a warmer era. I like these little “concrete” anecdotes, though their true meaning depends on exactly how old these remains are, and whether that timing correlates with warming in other places.

Ancient trees emerge from frozen forest ‘tomb’ Retreat of the Mendenhall Glacier reveals the remains of trees which grew more than 2,000 years ago By MARY CATHARINE MARTIN JUNEAU EMPIRE

The Mendenhall Glacier’s recession is unveiling the remains of ancient forests that have remained frozen beneath the ice for up to 2,350 years.

….

 

The most recent stumps she’s dated emerging from the Mendenhall are between 1,400 and 1,200 years old. The oldest she’s tested are around 2,350 years old. She’s also dated some at around 1,870 to 2,000 years old.

[...]

Roman Warming (was it global?)

Gullible Rudd steps right in it

Rudd let slip a line in his frustration this week that reveals how little he knows about the topic he holds so dear. He has so completely swallowed the PR on climate science, that when poked, he reflexively fires back exaggerated scientific claims that would make even the IPCC blush. In 2007 the IPCC and Gore et al offered Rudd the perfect Election-Wedge-on-a-Platter. They’d primed the audience with propaganda; trained the crowd to recite: Carbon is pollution. It looked like a no-brainer. Yet having based his leadership and campaign on it, it’s obvious he had not done even the most basic of checks (and still apparently hasn’t).

It’s an abject lesson in the importance of doing some homework before rewriting a nation’s economy.

Toga's don't keep you warm

Last week Tony Abbott (the Australian opposition leader) told school children that it was warmer ”at the time of Julius Caesar and Jesus of Nazareth”. This banal line set off a flurry of denial and bluster.

Rudd was incredulous in the Parliamentary Hansard record to the opposition members last week:

…how is it that, in the 21st century, you could support this Leader of the [...]

The big picture: 65 million years of temperature swings

Greenland Interglacial Temperatures – last 10,000 years. Are we headed for an ice age? (See below for more detail.)

David Lappi is a geologist from Alaska who has sent in a set of beautiful graphs–including an especially prosaic one of the last 10,000 years in Greenland–that he put together himself (and which I’ve copied here at the top).

If you wonder where today’s temperature fits in with the grand scheme of time on Earth since the dinosaurs were wiped out, here’s the history. We start with the whole 65 million years, then zoom in, and zoom in again to the last 12,000 from both ends of the world. What’s obvious is that in terms of homo sapiens history, things are warm now (because we’re not in an ice age). But, in terms of homo sapiens civilization, things are cooler than usual, and appear to be cooling.

Then again, since T-rex & Co. vanished, it’s been one long slide down the thermometer, and our current “record heatwave” is far cooler than normal. The dinosaurs would have scoffed at us: “What? You think this is warm?”

With so much volatility in the graphs, anyone could play “pick a trend” and depending [...]