One of the tools to reconstruct climate history in the Great Basin and North America Deserts (Mojave, Sonoran, etc.) are packrat middens. From the Wikipedia article on packrat middens:
Pack rats are known for their characteristic searching of materials to bring back to their nests creating an ever expanding collection known as a “midden” for its messiness. In natural environments, the middens are normally built out of sticks in rock crevices or caves for protection from predators. In the absence of crevices or caves, the middens are often built under trees or bushes. The pack rats will also use plant fragments, animal dung and small rocks in building the nest. The vast majority of the materials will be from a radius of several dozen yards of the nest. The pack rats urinate in the midden; sugar and other substances in the urine crystallizes as it dries out, creating a material known as amberat, cementing the midden together.
There are some amusing (or sickening, depending on how black your humors are) tales of Anglo explorers eating amberat, supposing it was some sort of desert bounty. After a couple of days (really) they quickly they were mistaken. shudder
Previously unexamined, perhaps because century- and millennial- depth deposits are seldom, if ever, allowed to accumulate, are the feline urine cemented deposits of ambercat that occur in cat litter boxes. Judging from the rapidity and volume that can be generated in geologically insignificant timescales (24 – 36 hours with multiple felines contributing to the ‘midden’) these proxies could be valuable for climatic reconstruction if deposits could be identified prior to the radiocarbon ‘recent.’
Absent its scientific value, I would personally be overjoyed to discover that ambercat had some sort of commercial value as our felines are apparently ‘top producers’ of ambercat, indeed in commercially viable quantities. I await your offers. There is a bagged sample at the curb right now.
[Blog Action Day] Climate Change presupposes that there is some sort of change coming in the status quo of climate not-change. And to a large extent, that is the case. I studied a variety of subjects but mostly circled around the most recent 25,000 years of this planet’s history. Lots of climate change there in those 25 millennia.
One thing is certain, and that is that climate change means changes in our world. Big changes. My experience covers things like woodlands becoming grasslands, and deserts emerging where herds of animals once grazed. Coastlines changed drastically as ocean levels went down when much of the northern hemisphere was covered with as much as 3 kilometers of ice.
When the average temperature rose again, millions of square miles of coast where animals (and humans) doubtlessly lived were again submerged as all that ice melted into the world’s oceans.
Relatives of ours, Neanderthals, disappeared. Lots of very conspicuous animals — huge grazers like mammoth and mastodons, woolly rhinoceros, giant ground sloths, and the predators that were dependent on them like saber-tooth cats, dire wolves, other cats and canine relatives — became extinct.
This particular episode will likely be unsurpassed since any in the last 7,000 years. It will be interesting, but not in a good way. More like the Chinese proverb, “May you live in interesting times.”
Perhaps we will go extinct
Well cool! Urm, pun not intended. Archaeologists seldom need quite that precision, but just to know that we’re closer to 12KYA than 11 is useful. Now on to that whole “Younger Dryas” event.
The result of a Danish ice drilling project has become the international standard for the termination of the last glacial period. It ended precisely 11,711 years ago.
Jørgen Peder Steffensen of the Niels Bohr Institute showing the exact point in the ice cap where the last Ice Age ended – 11,711 years ago. – Foto: Niels Bohr Instituttet
A Danish ice drilling project has conclusively ended the discussion on the exact date of the end of the last ice age.
The extensive scientific study shows that it was precisely 11,711 years ago – and not the indeterminate figure of ‘some’ 11,000 years ago – that the ice withdrew, allowing humans and animals free reign.
According to the Niels Bohr Institute (NBI) in Copenhagen, the very precise dating of the end of the last Ice Age has made Denmark the owner of the “Greenwich Mean Time” of the end of the last glacial period and beginning of the present climate – the so-called International Standard Reference.
Kilometres of ice
It took several thousand years to warm up the earth and melt the kilometre thick ice caps that covered large parts of the northern hemisphere during the last glacial period and as a result the transition from Ice Age to the current period has lacked a clearly defined point in time.
The answer has now been found in the NordGrip drilling project in Greenland.
“Our new, extremely detailed data from the examination of the ice cores shows that in the transition from the ice age to our current warm, interglacial period the climate shift is so sudden that it is as if a button was pressed”, explains ice core researcher Jørgen Peder Steffensen, Centre for Ice and Climate at NBI at the University of Copenhagen.
Ice core reference
When ice cores, that are formed by annual snowfall that is compressed into ice, are drilled out and analysed, the three kilometre ice cap in Greenland has acted like a filing cabinet of the climate detail of past geological periods.
“It is the first time an ice core has been used as an international standard reference for a geological period and it is a great recognition of our extremely detailed scientific data”, Jørgen Peder Steffensen said.
This is from a little while ago, but Asymptotic Life cut carbon emissions in their home by a whopping 70% after doing an energy audit — saving money in the process too. Here is how they did it