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4.2 Kiloyear Event
- MichaelMoser123 7y agohttps://en.m.wikipedia.org/wiki/List_of_periods_and_events_in_climate_history https://en.m.wikipedia.org/wiki/List_of_periods_and_events_i... 'List of periods and events in climate history'
- chrisco255 7y agoThese are very interesting. They do not get covered very often, but these events show climate changes in precipitation and temperature occur on the regular and cause even dramatic events (like the drying of the Sahara) naturally. I'm still trying to piece together what impacts geomagnetic excursions and reversals have on climate. During the last reversal 780,000 years ago the winter Asian monsoon was about 3x stronger than today according to one study I read.
- KnightOfWords 7y agoHistorical civilisations were very vulnerable to changes in local climate as they were heavily reliant on local food production, whereas we routinely ship food across oceans. Events like the [Little Ice Age](https://en.wikipedia.org/wiki/Little_Ice_Age https://en.wikipedia.org/wiki/Little_Ice_Age) barely show up in the global climate record. Earth's climate has varied greatly over time but its the current rate of change that is so alarming. During the last ice age it was about 4.5 degrees colder but it took 10,000 years to reach modern temperatures. We're currently on a path to changes of that magnitude within the next 70-100 years.
- chrisco255 7y agoYou're incorrect about your assumptions. If you click the link in the parent post, you'll see that temperatures swung as much as 8C during the ice age. These events are called Dansgaard-Oeschger events (https://en.wikipedia.org/wiki/Dansgaard%E2%80%93Oeschger_event https://en.wikipedia.org/wiki/Dansgaard%E2%80%93Oeschger_eve...) The warming would happen rapidly (within 3 decades), followed by a stepped down cooling period (often lasting hundreds of years). This happened repeatedly during the most recent glacial. And then more recently, after the last glacial period had ended, you had incidents like the Younger Dryas, for example, where temps plunged to near ice age levels (up to 6C drop in a few decades) and then rapidly warmed all of a sudden. If you read https://en.wikipedia.org/wiki/Younger_Dryas https://en.wikipedia.org/wiki/Younger_Dryas) some are suggesting that a warming episode at the end of the Younger Dryas occurred in as little as a few years and warmed global temps by 7C. Note, that by the end of the Younger Dryas, the Arctic was as much as 7C hotter than it is today (https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL084384?fbclid=IwAR38AO0dy7knA42dkG7UgTHLlL8H0la2iFYd2k1uqNyp7h7Ny2t61L0x42o https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019...). There's thousands of papers on the Little Ice Age. It certainly shows up all over the world in the fossil record. https://www.sciencedirect.com/search/advanced?qs=little%20ice%20age https://www.sciencedirect.com/search/advanced?qs=little%20ic...
- antocv 7y agoThats why I hate these Greta style "climate activists", since they only focus on climate, as if thats the only bad shit going on concerning environment. And even so, they are wrong about "apocalypse" style of events. Even if you solve atmospheric conditions, CO2 and temperature, still you have the pollution of the waters, mass extinctions due to habitat loss, car-tyres rubbering off everywhere, unknown untested toxins even on your cloths. Thats like, not talked about. EDIT: Cant believe somebody downvoted you. Yes nature has done fast changes, faster than human-induced change currently, and "nature" has mass-exterminated most of its life several times over, and other forms of life caused the deaths and biological disaster for most of other life on earth as well. These are facts. Somehow these Greata climate activists, would like to believe that humans are more powerful in their destruction than cyanobacteria. Wishful thinking really.
- saagarjha 7y agoWhat makes you think she doesn’t care about other aspects of the environment? She’s just focusing on climate change because it has an effect on all of those things too.
- roenxi 7y agoThe currently vocal environmentalist movement started from the left and picked up a lot more in the way of anti-capitalist sentiment, strong overtones of guilt and a real push to undertake acts of repentance and sacrifice. Their focus has pronounced overtones of repentance for our sins against the environment and has some very classically Christian themes. Things like the 'how dare you' comment to the UN help brand her as part of that specific branch of the environmentalist movement. She may personally care about who knows what, but the phenomenon that she looks to represent is a specific branch of environmentalism that is pushing different agenda to general environmental concerns. The environment-should-serve-humans-and-be-managed-to-do-so style environmentalists that used to be present in Australian right-wing politics have all but disappeared as the environmental issues they cared about are drowned out by people like Greta. I expect that has happened elsewhere too, and it is very easy to imagine that they don't see people like Greta as representing the environmental conservation issues they care about. The rather important concepts of practical sustainable living are drowned out by apocalyptic doomsayers who imply that the environmental costs of the rise of China and India are too great. Which just isn't going to gain traction, China and India represent 35% of the worlds population. We aren't going to give the environment some sort of primacy over the material comfort of 35% of the worlds population. People first, environment second. (My favourite graph at present: https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita#/media/File:2018_AQAL_Group_variwide_chart_%22Worldwide_Co2_emissions%22.jpg https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di... )
- bregma 7y agoThere's a good deal of observation bias at play here. We currently track the "average annual daily global mean temperature" to somewhere around 4 digits of precision, with an accuracy of around 3 digits of precision (back in the day my university TAs would fail any lab report with inverse precision like that, but I'm no PhD in climate science), and with a time frame of hours. Estimated historic temperatures are presented with 2 or 3 digits of precision over a timeframe of centuries or kiloyears. Saying current trends are unprecedented is motivational and technically correct, but not scientifically sound given the actual data. Well, science as in hard sciences like chemistry and physics in which we could run controlled experiments to generate confidence in our understanding; not soft sciences like economics or nutrition where controlled experiments would be unethical and results are only as good as the next product you're selling. My point is that you can see the current short-term trends because we have precision and accuracy to be able to do that. We lack the precision and accuracy of historical data to be able to do that, which makes it an argumentum ad ignorantiam.
- cbanek 7y agoI love learning about past Earth climate history and just history in general. One of my mind blowing climate events is: https://en.wikipedia.org/wiki/Messinian_salinity_crisis https://en.wikipedia.org/wiki/Messinian_salinity_crisis It's not in the list you link, but it's a pretty neat read. Basically, the Mediterranean dried up and refilled about 6 million years ago.
- flixic 7y agoNaming things is hard. Current name is relative to current date because it talks about an event 4200 years ago. Any literature discussing this will be stuck with this relative name and eventually will become incorrect. I understand why they don't want to use BC to name a global event that touched all cultures, and far before C was a thing. Maybe it would make sense to adopt kurzgesagt's Human Era calendar, starting at approximate time of first human settlements. They call current year 12019.
- lifthrasiir 7y agoNot exactly. A word "BP" in the full name ("4.2-kiloyear BP event") is a key: it stands for "Before Present", where the "Present" is defined as 1 Jan 1950 for the archaeological and geological purpose [1]. [1] https://en.wikipedia.org/wiki/Before_Present https://en.wikipedia.org/wiki/Before_Present
- sillysaurusx 7y agoSeems like evidence that our current climate change might be random. How do you rule out random climate variation scientifically? I'm curious, do we have enough data to say one way or the other? I'm hesitant to post this, since it seems like detached scientific conversation about climate change has been in short supply. But perhaps.
- Numberwang 7y agoIn what way is this evidence against man made climate change?
- sillysaurusx 7y agoIntense, world-changing climate change has been with us since long before fossil fuels. This is yet another instance. I am interested in the scientific methodology that rules out such variations and confirms that fossil fuels are in fact responsible. The time period is an obvious one: we seem to be seeing spikes in one century vs millennia. But the details of those spikes matter in comparison to our total historical record; hence the curiosity.
- prox 7y agoThis xkcd shows the long time graph into perspective with relevant notes : https://xkcd.com/1732 https://xkcd.com/1732
- Numberwang 7y agoYes it is important to look at the total historical record and have a scientific approach. But please look at the information graphed out and not just described as a set of anecdotes. And also take into account how the last centuries very dramatic changes relates to human fossil fuel consumption and changes in agriculture (both of which has an impact on the composition to the atmosphere). The scientific case for human impact is established. It is unfortunate bigger actions to mitigate the consequences will not happen. Whomever is alive in a 100 years time is likely to be born into a much more hostile world.
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- inspirel 7y agoClimate change over time.
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- Analyticss 7y agoClimate change over time. Earth actually experienced more than '4.2 Kiloyear Event'. 1.「4.2 Kiloyear event」 - A severe aridification event, occurring around 2200 B.C., that greatly contributed to the fall of the Akkadian empire. 2.「Medieval Warming Period」 - A warmer climate experienced especially in the Northern Hemisphere when Vikings and Inuit were moving to Greenland, around 800-1300 A.D. 3.「Little Ice Age」 - A cooler climate that eventually caused the demise of the Vikings, lasting from circa 1300-1850 A.D. 4.「The Holocene Era」 - Starting about 10,000 years ago, this era includes the Medieval Warming Period, the Little Ice Age, and continues all the way up until today!
- travisoneill1 7y agoThe chart in the article makes recent man made global warming look insignificant compared to recent changes. Much different than the often sited xkcd, https://xkcd.com/1732/ https://xkcd.com/1732/, which shows the same time period as basically a flat line. Who is right?
- fhars 7y agoBoth, one is a single data point at a single location, the other is global trend. The medieval warm period wasn‘t warmer than the average on average either, it was just a local fluctuation.
- guelo 7y agoAccording to this[1] that graph is frequently used by climate skeptics but it is outdated and incorrect. [1] https://www.carbonbrief.org/factcheck-what-greenland-ice-cores-say-about-past-and-present-climate-change https://www.carbonbrief.org/factcheck-what-greenland-ice-cor...
- monort 7y agoChart in xkcd is for global and smoothed temperature (proxy measurements with 200 years resolution), so it downplays abrupt and regional temperature changes like in Greenland or Younger Dryas https://earthscience.stackexchange.com/questions/9103/how-do-the-known-abrupt-climate-change-events-fit-into-the-xkcd-earth-temperatur https://earthscience.stackexchange.com/questions/9103/how-do...
- ffellow 7y agoAll the events in the wikipedia articles are localized, whereas the current global warming is a a global event, which is what is referenced by xkcd. What this means is that the frequency and/or the intensity of these local outlier events can increase significantly. This is what man-made climate change means and we can still avoid most of the negative effects if we want to. Often these local climate change events are taken as proof that 'climate has always changed'. Well, yes of course - but not on a global scale during human civilization as we know it. Personally, imagining these events occuring during our lifetime, maybe several at once or just a couple of decades apart scares the crap out of me.
- pts_ 7y agoFunny I just read this https://m.timesofindia.com/india/two-major-floods-wiped-out-several-medieval-indian-dynasties-study/articleshow/72716607.cms https://m.timesofindia.com/india/two-major-floods-wiped-out-...
- SideburnsOfDoom 7y agoWhat is the likely cause of this event?
- Amendeson530 7y ago4.2 kiloyear? 4200 year is actually fewer characters. Who says kiloyear?
- phkahler 7y agoWhat will this be called in 100 years?
- ithkuil 7y ago"Because the present changes every year, archaeologists, by convention, use A.D. 1950 as their reference. "
- g3orge 7y agoI love reading these kinds of wikipedia articles especially when it comes to reprecussions on ancient civilizations.. anyone got a book suggestion for s/t more detailed?
- pramsey 7y agoBest book on the subject I read is Wright's "A Short History of Progress" https://www.amazon.com/Short-History-Progress-Ronald-Wright/dp/0786715472 https://www.amazon.com/Short-History-Progress-Ronald-Wright/... Jared Diamond's "Collapse" is in a similar vein, but less cleanly written.