Wednesday, August 31, 2016

The Arctic ice was lower than today 6,000 years ago

And they had no anthropogenic global warming then!  So could the present ice level be just another natural fluctuation? If not, why not?

Arctic Ocean perennial sea ice breakdown during the Early Holocene Insolation Maximum

Christian Strannea et al.


Arctic Ocean sea ice proxies generally suggest a reduction in sea ice during parts of the early and middle Holocene (∼6000–10,000 years BP) compared to present day conditions. This sea ice minimum has been attributed to the northern hemisphere Early Holocene Insolation Maximum (EHIM) associated with Earth's orbital cycles. Here we investigate the transient effect of insolation variations during the final part of the last glaciation and the Holocene by means of continuous climate simulations with the coupled atmosphere–sea ice–ocean column model CCAM. We show that the increased insolation during EHIM has the potential to push the Arctic Ocean sea ice cover into a regime dominated by seasonal ice, i.e. ice free summers. The strong sea ice thickness response is caused by the positive sea ice albedo feedback. Studies of the GRIP ice cores and high latitude North Atlantic sediment cores show that the Bølling–Allerød period (c. 12,700–14,700 years BP) was a climatically unstable period in the northern high latitudes and we speculate that this instability may be linked to dual stability modes of the Arctic sea ice cover characterized by e.g. transitions between periods with and without perennial sea ice cover.


Ice scares aren’t all they’re cracked up to be

The sea ice in the Arctic Ocean is approaching its annual nadir. By early September each year about two-thirds of the ice cap has melted, then the sea begins to freeze again. This year looks unlikely to set a record for melting, with more than four million square kilometres of ice remaining, less than the average in the 1980s and 90s, but more than in the record low years of 2007 and 2012. (The amount of sea ice around Antarctica has been increasing in recent years, contrary to predictions.)

This will disappoint some. An expedition led by David Hempleman-Adams to circumnavigate the North Pole through the Northeast and Northwest passages, intending to demonstrate “that the Arctic sea ice coverage shrinks back so far now in the summer months that sea that was permanently locked up now can allow passage through”, was recently held up for weeks north of Siberia by, um, ice. They have only just reached halfway.

Meanwhile, the habit of some scientists of predicting when the ice will disappear completely keeps getting them into trouble. NASA climate scientist Jay Zwally told the Associated Press in 2007: “At this rate, the Arctic Ocean could be nearly ice-free at the end of summer by 2012.” Two years later Al Gore quoted another scientist that “there is a 75 per cent chance that the entire north polar ice cap, during the summer months, could be completely ice-free within five to seven years” — that is, by now.

This year Professor Peter Wadhams of Cambridge University has a new book out called Farewell to Ice, which gives a “greater than even chance” that the Arctic Ocean will be ice-free next month. Not likely.

He added: “Next year or the year after that, I think it will be free of ice in summer … You will be able to cross over the North Pole by ship.” The temptation to predict a total melt of the Arctic ice cap, and thereby get a headline, has been counter-productive, according to other scientists. Crying wolf does not help the cause of global warming; it only gives amusement to sceptics.

Would it matter if it did all melt one year? Here’s the point everybody seems to be missing: the Arctic Ocean’s ice has indeed disappeared during summer in the past, routinely. The evidence comes from various sources, such as beach ridges in northern Greenland, never unfrozen today, which show evidence of wave action in the past. One Danish team concluded in 2012 that 8500 years ago the ice extent was “less than half of the record low 2007 level”. A Swedish team, in a paper published in 2014, went further: between 10,000 years ago and 6000 years ago, the Arctic experienced a “regime dominated by seasonal ice, ie, ice-free summers”.

This was a period known as the “early Holocene insolation maximum” (EHIM). Because the Earth’s axis was tilted away from the vertical more than today (known as obliquity), and because we were then closer to the Sun in July than in January (known as precession), the amount of the Sun’s energy hitting the far north in summer was much greater than today. This “great summer” effect was the chief reason the Earth had emerged from an ice age, because hot northern summers had melted the great ice caps of North America and Eurasia, exposing darker land and sea to absorb more sunlight and warm the whole planet.

The effect was huge: about an extra 50 watts per square metre 80 degrees north in June. By contrast, the total effect of man-made global warming will reach 3.5 watts per square metre (but globally) only by the end of this century.

To put it in context, the EHIM was the period during which agriculture was invented in about seven different parts of the globe at once. Copper smelting began; cattle and sheep were domesticated; wine and cheese were developed; the first towns appeared. The seas being warmer, the climate was generally wet so the Sahara had rivers and forests, hippos and people.

That the Arctic sea ice disappeared each August or September in those days does not seem to have done harm (remember that melting sea ice, as opposed to land ice, does not affect sea level), and nor did it lead to a tipping point towards ever-more rapid warming. Indeed, the reverse was the case: evidence from stalagmites in tropical caves, sea-floor sediments and ice cores on the Greenland ice cap shows that temperatures gradually but erratically cooled over the next few thousand years as the obliquity of the axis and the precession of the equinoxes changed. Sunlight is now weaker in July than January again (on global average).

Barring one especially cold snap 8200 years ago, the coldest spell of the past 10 millennia was the very recent “little ice age” of AD1300-1850, when glaciers advanced, tree lines descended and the Greenland Norse died out.

It seems that the quantity of Arctic sea ice varies more than we used to think. We don’t really know how much ice there was in the 1920s and 30s — satellites only started measuring it in 1979, a relatively cold time in the Arctic — but there is anecdotal evidence of considerable ice retreat in those decades, when temperatures were high in the Arctic.


Warmists (sort of) eat humble pie

A paper from 2013 below that has lost none of its relevance today.  They say that their models predicted twice as much warming as has actually occurred and they admit the C21 "hiatus".  And they can only guess why it all went so wrong

Recent observed global warming is significantly less than that simulated by climate models. This difference might be explained by some combination of errors in external forcing, model response and internal climate variability.

Global mean surface temperature over the past 20 years (1993–2012) rose at a rate of 0.14 ± 0.06 °C per decade (95% confidence interval). This rate of warming is significantly slower than that simulated by the climate models participating in Phase 5 of the Coupled Model Intercomparison Project (CMIP5). To illustrate this, we considered trends in global mean surface temperature computed from 117 simulations of the climate by 37 CMIP5 models (see Supplementary Information).

These models generally simulate natural variability — including that associated with the El Niño–Southern Oscillation and explosive volcanic eruptions — as well as estimate the combined response of climate to changes in greenhouse gas concentrations, aerosol abundance (of sulphate, black carbon and organic carbon, for example), ozone concentrations (tropospheric and stratospheric), land use (for example, deforestation) and solar variability. By averaging simulated temperatures only at locations where corresponding observations exist, we find an average simulated rise in global mean surface temperature of 0.30 ± 0.02 °C per decade (using 95% confidence intervals on the model average).

The observed rate of warming given above is less than half of this simulated rate, and only a few simulations provide warming trends within the range of observational uncertainty (Fig. 1a).

The inconsistency between observed and simulated global warming is even more striking for temperature trends computed over the past fifteen years (1998–2012). For this period, the observed trend of 0.05 ± 0.08 °C per decade is more than four times smaller than the average simulated trend of 0.21 ± 0.03 °C per decade (Fig. 1b). It is worth noting that the observed trend over this period — not significantly different from zero — suggests a temporary ‘hiatus’ in global warming. The divergence between observed and CMIP5- simulated global warming begins in the early 1990s, as can be seen when comparing observed and simulated running trends from 1970–2012 (Fig. 2a and 2b for 20-year and 15-year running trends, respectively the current generation of climate models (when run as a group, with the CMIP5 prescribed forcings) do not reproduce the observed global warming over the last 20 years, or the slowdown in global warming over the past fifteen years. This interpretation is supported by statistical tests of the null hypothesis that the observed and model mean trends are equal, exchangeable with each other (that is, the ‘truth plus error’ view); or (2) the models are exchangeable with each other and with the observations (see Supplementary Information).

Differences between observed and simulated 20-year trends have p values (Supplementary Information) that drop to close to zero by 1993–2012 under assumption (1) and to 0.04 under assumption (2) (Fig. 2c). Here we note that the smaller the p value is, the stronger the evidence against the null hypothesis. On this basis, the rarity of the 1993–2012 trend difference under assumption (1) is obvious. Under assumption (2), this implies that such an inconsistency is only expected to occur by chance once in 500 years, if 20-year periods are considered statistically independent. Similar results apply to trends for 1998–2012 (Fig. 2d). In conclusion, we reject the null hypothesis that the observed and model mean trends are equal at the 10% level.


H/T Paul Homewood

Warmest EVER?

We are bombarded with claims that some month or year (e.g., 2016) is the “warmest ever.” But what does that mean? We are living in a relatively cool era. Temperatures today are lower than they have been something like 90% of the time since the last Ice Age ended 12,000 or so years ago. In fact, “ever” means since approximately the 1880s, when thermometer records became widespread. As it happens, that was also around the time when the Little Ice Age ended, so–happily!–the Earth is a bit warmer now than it was then.

One of the many problems with global warming hysteria is that it is based on the surface temperature record since the 1880s, which is deeply flawed when it is not outright falsified by alarmists who control the historical records. This happens often, as we and others have documented. This week’s The Week That Was from the Science and Environmental Policy Project explains some (but by no means all) additional problems with the surface temperature record:

Unfortunately, the IPCC, and others, use surface temperatures to evaluate the global climate models. The failure of the models to track the surface temperatures is not surprising. Historic data is very sparse, largely from western Europe and the US. The data is contaminated by significant changes in land use, particularly urbanization. And, as shown in the 2008 NIPCC report, since about 1970, there has been a marked decline in the stations used to establish surface temperatures, and dramatic decline in the number of 5 degree by 5 degree grid boxes covered. Around the year 2000 about 100 of the total of 2,592 possible grid boxes ([180/5] x [360/5]) were covered – 4%. Complicating matters has been the trend, at least in the US, of using stations at airports. Both pavement and flying frequency create measurement problems.

When the Charney report was produced in 1979, there were no comprehensive, global temperature data. But starting in 1989, going back to December 1978, we have had comprehensive global satellite data of the atmosphere. As shown in the report by John Christy, the comprehensive satellite data show that, generally, the global climate models greatly overestimate warming of the atmosphere, where the greenhouse effect occurs. Both satellite and surface data are influenced by weather events such as the El Niño Southern Oscillation (ENSO). But, since the satellite data is “cleaner” it should be easier to separate natural and other human effects from CO2 caused warming.

If the purpose of the models is to estimate the effect of CO2, then surface data are poor proxy data at best. Atmospheric data is far superior. The kindest possible justification for the IPCC, and others, not to use satellite data is mental inertia.

Actually, the explanation is political. The IPCC was explicitly established by the U.N. for one purpose only, to “study” the impact of human-emitted CO2 on global temperatures. This was for the purpose of justifying government control over industry worldwide. Anyone who is interested in science rather than left-wing politics relies on the satellite data, which are transparent and have not been “adjusted” by political activists.


EPA spills again in Colorado

The Environmental Protection is admitting to a spill from a treatment plant it set up after it dumped 3 million gallons of toxic wastewater into a Colorado river last year.

The EPA said Thursday night that the spill happened on Tuesday, and officials are still attempting to determine how much and what metals were contained in the sludgy discharge, according to the Associated Press.

The spill occurred near the site of last year's spill at the abandoned Gold King Mine in Silverton, Colo., where agency contractors didn't adequately check the mine's pressure before attempting to open it up after several years of being idle. The result was a massive mine blowout that sent 3 million gallons of metal-tainted water into the waterways of three states.

The Navajo Nation sued the agency over the spill last week after the EPA inspector general and the Justice Department opened a criminal investigation into the incident a few days before the Aug. 5 anniversary of the 2015 spill. The Navajo argue in their lawsuit that the spill significantly harmed the tribe's primary source of revenue from crops and other agricultural products.

Local officials said this week's release was not large enough to warrant a public advisory.

Last year's spill sent nearly 1 million pounds of metals into the waterways of the Animas and San Juan rivers, which traverse three states. The metals include arsenic, cadmium, copper, lead, mercury, nickel and zinc.

This week's spill came from the treatment plant that the EPA set up near the mine to filter water coming from the mine before releasing it into the creek and river systems. A large amount of rain in Colorado caused the treatment facility to overflow and some of the untreated water to spill into the waterways.

EPA said the water that spilled from he plant was partially treated, and the metals present in it should quickly settle to the bottom of waterways where they are less harmful.


Australian Report Predicts Global Coffee Shortage Will Get Worse

It's hard to know where to start in dismissing this nonsense.  All that global warming would do for ANY crop is to shift polewards the areas where it was grown.  There is no conceivable reason for an OVERALL shortage.  There are always new areas opening up for coffee growing anyway.

Secondly, the current problem is described as drought.  Yet a warming world would mean a wetter world so warming could in fact SOLVE problems of coffee growing!

Thirdly, if they understood any economics they would know that any lasting reduction in supply would cause price increases and sustained price increases would then draw out more supply.  Australia's empty North, for instance, could undoubtedly be opened up to coffee growing in some parts.  There is already a small operation on the Atherton Tableland.  They even grow Arabica there

A new report from Australia's Climate Institute predicts that by 2050, global warming will make at least half of the land currently used for coffee production unable to produce quality beans.

By 2080, it cautions, hot temperatures could make wild coffee plants completely extinct. Although this report is projecting what will happen to supplies in decades to come, the coffee shortage isn't really off in the distant future.

It's already started to fall.  Brazil -- the source for over a third of the world's coffee -- has seen its coffee stores dip dramatically in the last two years as the result of a long drought.  So far, unusually large harvests in other world coffee markets helped to make up most of the difference.

But we can hardly expect these big harvests to continue. In fact, their trend may actually reverse.

Much of Brazil's latest shortfall was made up for by a record-breaking coffee harvest in Honduras -- which is a coffee-growing area that this new report says will probably be hit particularly hard in the coming decades.

Even the relatively smaller shift from Brazil's shortage in the last couple years resulted in a price surge and a jump in counterfeit coffee beans (which pretend to be fancier coffee varieties than they are).

With the spread of the shortage, we can only expect to see rising coffee prices and counterfeiting show up as even more of a problem in our daily cups.



For more postings from me, see  DISSECTING LEFTISM, TONGUE-TIED, EDUCATION WATCH INTERNATIONAL, POLITICAL CORRECTNESS WATCH, FOOD & HEALTH SKEPTIC and AUSTRALIAN POLITICS. Home Pages are   here or   here or   here.  Email me (John Ray) here.  

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