|
|
The message to the world is unequivocal:
“We are heading for somewhere that is far off from anything we have seen in the past 10,000 years – it’s through the roof. In my mind, we are heading for a different planet to the one that we have been used to,” said Jeremy Shakun of Harvard University, a co-author of the study.
Source: The-world-is-hottest-it-has-been-since-the-end-of-the-ice-age–and-the-temperatures-still-rising.
There are two factors in the new Marcott paper that are major red flags. For one, there is hardly any data in the modern end of the graph. Ponder how researchers can find 5,000 year old Foraminifera deposits, but not ones from 1940? Two: they’ve smoothed the heck out of longer periods. Marcott et al clearly say there is “…essentially no variability preserved at periods shorter than 300 years…” So if there were, say, occurrences of a warming rise exactly like the last century, this graph won’t show them.
Some of the data has a resolution as poor as “500 years” and the median is 120 years. If current temperatures were averaged over 120 years (that would be 1890 to now), the last alarming spike would blend right in with the other data. Where would the average […]
There have been suggestions that Jo Nova might be trying to hide or ignore the most recent boreholes graph from Huang et al. So here it is. This is the last 2,000 years according to 6000 boreholes, with the last 100 years also using the “instrumental record” which gives us that hockey-stick uptick at the end. Below I explain the pros and cons of this study and update my thoughts.
Huang and Pollack 2008: Their latest boreholes published study
A borehole sounds like a bit-of-a-stretch as a proxy. How could we tell if the world was warmer in 1066 by drilling a hole in the ground? Yes, fair point. But what makes boreholes useful is that they are global and there is a lot of data: specifically 6,000 holes all over the world.
I’ve been looking at boreholes in more detail, analyzing them in the light of newer proxies. When all the evidence is considered, boreholes turn out be not-much-use at giving us meaningful numbers in degrees C, and in my opinion, not-too-hot at telling us the “when” of an event either. Too much depends on assumptions.
But what are they good for is that, when combined with […]
Antarctic Glacier Image: Paomic
It comes as not even a tiny surprize that when someone asks “Where does all the CO2 go in an ice age?” that the answer is “The Ocean“.
We already know temperatures rise 800 years before CO2 levels (Caillon 2003), and we know the oceans contain 50 times as much CO2 as the sky. Moreover, basic chemistry tells us that CO2 (like all gases) will dissolve better in cold water, and be released as the water warms. To cap it all off, the deep abyss of the oceans turns over once every millenia or so (which fits loosely with the “lag” between temperature and CO2 levels).
But you would think this new research was solving a deep mystery, rather than confirming what most sane knowledgeable people would expect. Nonetheless, this may be the first detailed study of C13 levels going back 24,000 years.
CO2 was hidden in the ocean during the Ice Age
EurekaAlert
Why did the atmosphere contain so little carbon dioxide (CO2) during the last Ice Age 20,000 years ago? Why did it rise when the Earth’s climate became warmer? Processes in the ocean are responsible for this, says […]
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 […]
Ice cores reveal that CO2 levels rise and fall hundreds of years after temperatures change
In 1985, ice cores extracted from Greenland revealed temperatures and CO2 levels going back 150,000 years. Temperature and CO2 seemed locked together. It was a turning point—the “greenhouse effect” captured attention. But, in 1999 it became clear that carbon dioxide rose and fell after temperatures did. By 2003, we had better data showing the lag was 800 ± 200 years. CO2 was in the back seat.
8 out of 10 based on 24 ratings […]
|
JoNova A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).
Jo appreciates your support to help her keep doing what she does. This blog is funded by donations. Thanks!
Follow Jo's Tweets To report "lost" comments or defamatory and offensive remarks, email the moderators at: support AT joannenova.com.au
Statistics
The nerds have the numbers on precious metals investments on the ASX
|
Recent Comments