Showing posts with label Little Ice Age. Show all posts
Showing posts with label Little Ice Age. Show all posts

Wednesday, March 28, 2012

Global Warming Models Are Wrong Again

Wall Street Journal
William Happer

The observed response of the climate to more CO2 is not in good agreement with predictions.

During a fundraiser in Atlanta earlier this month, President Obama is reported to have said: "It gets you a little nervous about what is happening to global temperatures. When it is 75 degrees in Chicago in the beginning of March, you start thinking. On the other hand, I really have enjoyed nice weather."

What is happening to global temperatures in reality? The answer is: almost nothing for more than 10 years. Monthly values of the global temperature anomaly of the lower atmosphere, compiled at the University of Alabama from NASA satellite data, can be found at the website http://www.drroyspencer.com/latest-global-temperatures/. The latest (February 2012) monthly global temperature anomaly for the lower atmosphere was minus 0.12 degrees Celsius, slightly less than the average since the satellite record of temperatures began in 1979.

The lack of any statistically significant warming for over a decade has made it more difficult for the United Nations Intergovernmental Panel on Climate Change (IPCC) and its supporters to demonize the atmospheric gas CO2 which is released when fossil fuels are burned. The burning of fossil fuels has been one reason for an increase of CO2 levels in the atmosphere to around 395 ppm (or parts per million), up from preindustrial levels of about 280 ppm.
CO2 is not a pollutant. Life on earth flourished for hundreds of millions of years at much higher CO2 levels than we see today. Increasing CO2 levels will be a net benefit because cultivated plants grow better and are more resistant to drought at higher CO2 levels, and because warming and other supposedly harmful effects of CO2 have been greatly exaggerated. Nations with affordable energy from fossil fuels are more prosperous and healthy than those without.

The direct warming due to doubling CO2 levels in the atmosphere can be calculated to cause a warming of about one degree Celsius. The IPCC computer models predict a much larger warming, three degrees Celsius or even more, because they assume changes in water vapor or clouds that supposedly amplify the direct warming from CO2. Many lines of observational evidence suggest that this "positive feedback" also has been greatly exaggerated.

There has indeed been some warming, perhaps about 0.8 degrees Celsius, since the end of the so-called Little Ice Age in the early 1800s. Some of that warming has probably come from increased amounts of CO2, but the timing of the warming—much of it before CO2 levels had increased appreciably—suggests that a substantial fraction of the warming is from natural causes that have nothing to do with mankind.

Monday, March 26, 2012

Medieval Warm Period Was Worldwide


• Evidence was found in a rare mineral that records global temperatures


• Warming was global and NOT limited to Europe


• Throws doubt on orthodoxies around 'global warming'

DailyMail
Ted Thornhill

Current theories of the causes and impact of global warming have been thrown into question by a new study which shows that during medieval times the whole of the planet heated up.

It then cooled down naturally and there was even a 'mini ice age'.

A team of scientists led by geochemist Zunli Lu from Syracuse University in New York state, has found that contrary to the ‘consensus’, the ‘Medieval Warm Period’ approximately 500 to 1,000 years ago wasn’t just confined to Europe.

In fact, it extended all the way down to Antarctica – which means that the Earth has already experience global warming without the aid of human CO2 emissions.



At present the Intergovernmental Panel on Climate Change (IPCC) argues that the Medieval Warm Period was confined to Europe – therefore that the warming we’re experiencing now is a man-made phenomenon.

However, Professor Lu has shown that this isn’t true – and the evidence lies with a rare mineral called ikaite, which forms in cold waters.

‘Ikaite is an icy version of limestone,’ said Lu. ‘The crystals are only stable under cold conditions and actually melt at room temperature.’

It turns out the water that holds the crystal structure together - called the hydration water - traps information about temperatures present when the crystals formed.

This finding by Lu's research team establishes, for the first time, ikaite as a reliable way to study past climate conditions.



The scientists studied ikaite crystals from sediment cores drilled off the coast of Antarctica. The sediment layers were deposited over 2,000 years. 

The scientists were particularly interested in crystals found in layers deposited during the ‘Little Ice Age,’ approximately 300 to 500 years ago, and during the Medieval Warm Period before it.


Both climate events have been documented in Northern Europe, but studies have been inconclusive as to whether the conditions in Northern Europe extended to Antarctica.
Lu’s team found that in fact, they did.

They were able to deduce this by studying the amount of heavy oxygen isotopes found in the crystals. 

During cool periods there are lots, during warm periods there aren’t.
‘We showed that the Northern European climate events influenced climate conditions in Antarctica,’ Lu says. ‘More importantly, we are extremely happy to figure out how to get a climate signal out of this peculiar mineral. A new proxy is always welcome when studying past climate changes.’

The research was recently published online in the journal Earth And Planetary Science Letters and will appear in print on April 1.

Friday, August 5, 2011

Blockbuster: Planetary temperature controls CO2 levels — not humans

JoNova

There goes another “fingerprint”…

It’s not just that man-made emissions don’t control the climate, they don’t even control global CO2 levels.
Judging by the speech gave at the Sydney Institute, there’s a blockbuster paper coming soon.
Professor Murry Salby is Chair of Climate Science at Macquarie University. He’s been a visiting professorships at Paris, Stockholm, Jerusalem, and Kyoto, and he’s spent time at the Bureau of Meterology in Australia.

Over the last two years he has been looking at C12 and C13 ratios and CO2 levels around the world, and has come to the conclusion that man-made emissions have only a small effect on global CO2 levels. It’s not just that man-made emissions don’t control the climate, they don’t even control global CO2 levels.

The higher levels of CO2 in recent decades appear to be mostly due to natural sources. He presented this research at the IUGG conference in Melbourne recently, causing great discussion and shocking a few people. Word reached the Sydney Institute, which rushed to arrange for him to speak, given the importance of this work in the current Australian political climate.



The ratio of C13 to C12 (two isotopes of carbon) in our atmosphere has been declining, which is usually viewed as a signature of man-made CO2 emissions. C12 makes up 99% of carbon in the atmosphere (nearly all atmospheric carbon is in the form of CO2). C13 is much rarer — about 1%. Plants don’t like the rarer C13 type as much; photosynthesis works best on the C12 -type -of-CO2 and not the C13-type when absorbing CO2 from the air.

Prof Salby points out that while fossil fuels are richer in C12 than the atmosphere, so too is plant life on Earth, and there isn’t a lot of difference (just 2.6%) in the ratios of C13 to C12 in plants versus fossil fuels. (Fossil fuels are, after all, made in theory from plants, so it’s not surprising that it’s hard to tell their “signatures” apart). So if the C13 to C12 ratio is falling (as more C12 rich carbon is put into the air by burning fossil fuels) then we can’t know if it’s due to man-made CO2 or natural CO2 from plants.

Essentially we can measure man-made emissions reasonably well, but we can’t measure the natural emissions and sequestrations of CO2 at all precisely — the error bars are huge. Humans emits 5Gt or so per annum, but the oceans emit about 90Gt and the land-plants about 60Gt, for a total of maybe 150Gt. Many scientists have assumed that the net flows of carbon to and from natural sinks and sources of CO2 cancel each other out, but there is no real data to confirm this and it’s just a convenient assumption. The problem is that even small fractional changes in natural emissions or sequestrations swamp the human emissions.

UPDATE Inserted: E.M.Smith covered this point well in 2009


“It is often asserted that we can measure the human contribution of CO2 to the air by looking at the ratio of C12 to C13. The theory is that plants absorb more C12 than C13 (by about 2%, not a big signature), so we can look at the air and know which came from plants and which came from volcanos and which came from fossil fuels, via us. Plants are ‘deficient’ in C13, and so, then, ought to be our fossil fuel derived CO2.

The implication is that since coal and oil were from plants, that “plant signature” means “human via fossil fuels”. But it just isn’t that simple. Take a look at the above chart. We are 5.5 and plants are putting 121.6 into the air each year (not counting ocean plants). There is a lot of carbon slopping back and forth between sinks and sources. Exactly how closely do we know the rate of soil evolution of CO2, for example?”

Chiefio also found some interesting quotes pointing out that corn (a C4 plant) absorbs more C13, and our mass fields of corn might just muck up the stats… (it’s a good post).

The sources of CO2 don’t seem to be industrialized areas

Suspiciously, when satellites record atmospheric CO2 levels around the globe they find that the sources don’t appear to be concentrated in the places we’d expect — industry or population concentrations like western Europe, the Ohio Valley, or China. Instead the sources appear to be in places like the Amazon Basin, southeast Asia, and tropical Africa — not so much the places with large human emissions of CO2!