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Showing posts with the label apocalypse

Ice Age vs Global Warming

Do you know what one significant difference is between Uranus and all the other planets in the solar system? Unlike the other seven planets, which, more or less, rotate in a "normal" up-down position (or down-up in the case of Venus), Uranus is quite abnormal. Its north-south pole rotational axis lies almost in the ecliptic because it is tilted by 97.8 degrees and rotates in an almost vertical direction toward the orbiting plane. In simple words, Uranus is one giant rolling ball where, if you are located on its pole, you would be experiencing only one day and one night during its 84-year-long orbit, while if you are settled near the equator, thanks to the ultra-fast rotation time (for a giant planet) of 17 hours, you would be experiencing fast switching between day and night, and during both solstices, the Sun would always be on the horizon. Thanks to this strange position of Uranus' axis (probably due to some cosmic collision that happened in the early solar system), the weather and climate on Uranus are always dramatic in the form of huge apocalyptic storms one after another.

Uranus—a hypothetical view from the nearest moon

Of course, we don't have to go that far outside the Sun's habitable zone to prove that the position of the rotational axis can cause dramatic climate changes on the planet's surface. Let's look in our own front yard and see how a couple of main astronomical properties influence the climate on Earth. Is it possible that even a slight change in, for example, Earth's orbit can cause some dramatic climate changes over the years? I am sure this question was exactly what was itching Milutin Milankovitch's mind almost a century ago when he first read James Croll's bold idea of the effects of variations of the Earth's orbit on climate cycles. Croll's theory was generally rejected by the scientific mainstream at the time, but this didn't stop Milankovitch from expanding his idea and eventually creating a mathematical model capable of calculating the time frames of all climate changes that happened in the past half a million years and further. Today this theory is well known as Milankovitch Cycles or Insolation Theory, with approximately 100,000 years of cyclicity between ice ages.

Unfortunately, Milankovitch died some 20 years before his model was proven in 1976, when one geological study confirmed consistency of the calculated data with the examined deep-sea sediment cores. Past records of temperature measurement provided by the Foresight Institute recovered from a Greenland ice core also show a drop in temperature for the past 50,000 years similar to the Milankovitch graph shown below. The last curve in the graph represents stages of glaciation, or, in simple words, turning the Earth into a giant ice ball in the past million years. The peaks (hot and cold) are called interglacial and glacial periods. Right now we are living in the fourth interglacial period in the past 400,000 years, and soon, astronomically speaking, we are going to start heading back toward another ice age. Exactly when it is going to happen is hard to predict, but before speculating about future time frames, let's first try to understand the first three curves.


The basics under the theory are so-called insolation calculations based on orbital cycles (cycled amount of sunlight hitting the Earth). Milankovitch used Ludwig Pilgrim's orbital calculations to make a detailed model of insolation periods initially for the previous 130,000 years (later expanded to 650,000 years). Three orbital variations are used in this complex math. The first one is changes in Earth's orbit around the sun (eccentricity), the second is the tilt of Earth's axis (obliquity), and the third represents the wobble of Earth's axis (precession).

The Eccentricity Cycle (Elliptical Cycle)
Due to other planets' gravitational influences, Earth's orbit has an approximate 100,000-year cycle of slight changes. It goes from a nearly circular orbit toward a mildly elliptical one. During the "elliptical" period, Earth is receiving less solar radiation compared to the "circular" part.

The Obliquity Cycle (Axial Tilt)
We saw in the beginning how Uranus' unusual axial tilt can cause dramatic climate. With the exception of Mercury and Venus with their almost vertical no-tilt position of rotational axis (if we disregard Venus's almost 180° tilt positioning the planet upside down), all other planets are tilted around 25 degrees. This means that a planet's hemispheres can be tilted toward or against the Sun, giving the planet seasons with different amounts of sunshine during one orbit cycle. The lower angle means that sun rays are penetrating the atmosphere better, warming the surface more compared to the planet's other hemisphere, where the angle is higher. Now if we add the fact that the axis angle is changing over time, and in Earth's case this goes from 22.1° to 24.5° and back again over a period of 41,000 years, it is obvious that when this axial tilt changes over time by as little as 1 degree, it can cause serious effects to the global insolation mentioned above.

The Precession Cycle (Wobble)
The last, but not the least, motion in this equation is Earth's wobbling. Not only is that axis changing its angle over time, but it also, like some spin-top toy, wobbles. This "feature" is positioning Earth's axis today almost directly toward Polaris, commonly known as the "North Star", and in half a period of time it will be pointing directly to Vega. This is caused by the planet not being a perfect round ball and also by the close vicinity of the Sun and the Moon with their strong gravitational forces. This cycle is the shortest, and it occurs every 26,000 years.


Doctor Who in one of the episodes said that he was capable of feeling all these motions as they happen, but hopefully and thankfully, in the real world, we humans are too small in both size and time frame of our individual existence; otherwise, I am not sure what the exact consequence would be if we could really sense planetary motions. Sci-fi aside, all these three motion cycles can cause changes in the quantity of sunlight hitting the Earth's surface, and insolation theory in a nutshell is basically one mathematical model capable of calculating solar forcing (yellow line in the above graph) for any chosen latitude at any point in time, considering the orbital position of the Earth and the condition of the planetary axis. Of course, even though this theory has overwhelming support in mainstream science, it's still far from being perfect. There are problems and concerns posted in previous years and decades, and the main one is that it doesn't include the inclination of the earth's orbit to the ecliptic, which is another 100,000-year cycle, more or less. Also, in observed glacial data, even though the 100ky cycle is recognized, the temperature records do not correlate perfectly with insolation theory. There are more suggestions, like including the longest eccentricity cycle or 400,000 years of carbon dioxide variations in oceans and even including consequences of "artificial" production of greenhouse gases since the early 19th century and the birth of the industrial revolution. In other words, the theory has plenty of room for improvement, and its perfection is expected.

One thing is for sure: this research is one of the most complex sciences out there. There are simply too many inputs and variables. One historical data point I read in Wikipedia was that Milankovitch needed 100+ days to manually calculate cycles for the past 650,000 years and only for three latitudes.

Leonardo DiCaprio's Before the flood

Ok, now that we know how Earth "works" in relation to its own climate, I think it is the perfect time in this post to ask the obvious question(s). As we know for sure that we have been living for some time now in the peak of an interglacial period, is it possible to use the theory and glacial data to predict the next ice age? More importantly, are humans capable enough to postpone the next ice age with emissions of carbon dioxide and other greenhouse gases? In the Nature Geoscience paper named "Determining the natural length of the current interglacial" they concluded that, according to all we know about insolation and CO2 forcing, the next ice age is very close, and it should start happening within the next 1500 years. The only condition is for atmospheric CO₂ concentrations to be lower than 240±5 ppmv.

Guess what? On this very day it is 400 ppmv (May, 2013).

Well, now is the time for an even more obvious question. Did we cross the point of no return? Did we manage to cheat natural astronomical cycles and actually head toward global warming instead of an ice age? Or the oceans will prevail one more time and over the next millenniums will manage to absorb a record amount of carbon dioxide in the previous million years and introduce the next ice age with little delay this time? Again, some facts are pointing toward two cruel possible scenarios. If the next ice age eventually comes, it will ultimately pose a significant threat to mankind in the form of a lack of energy, food, and enough landmasses to sustain a large human population, not to mention all other species. On the other hand, if CO₂ levels uncontrollably continue to rise, the resulting global warming is equally or even more dangerous. Melted ice will raise ocean levels and sink large coastal cities all over the world. About 10% of people live in low-elevation coastal zones. Just imagine the migration of 600 million people in the potential scenario of global warming.

The Expanse—Flood blockage in futuristic NYC

This is the lottery we cannot win. It seems that time is running out, and within the next decade, we need to find a solution for ultimate control of greenhouse gases. Additionally, with all potential hazards on the way, it seems that we can't allow nature to take us in some dramatic ice age or global warming.

It's a simple matter of pure survival.

No pressure.

Original post date: June 2013, Updates: November 2016, December 2017

Image ref:
https://www.beforetheflood.com/
https://sites.google.com/a/isd47.org/rogersesci2015third/home/20-the-weirdest-tilt
http://www.imdb.com/title/tt3230854/

Story refs:
http://en.wikipedia.org/wiki/Milankovitch_cycles
http://www.imdb.com/title/tt0436992/

More references:
http://www.universetoday.com/19305/seasons-on-uranus/
http://en.wikipedia.org/wiki/Ice_age
http://www.bbc.co.uk/news/science-environment-16439807
http://co2now.org/
http://ossfoundation.us/projects/environment/global-warming/milankovitch-cycles
http://muller.lbl.gov/pages/IceAgeBook/IceAgeTheories.html
http://www.eoearth.org/view/article/154612/
http://frank-davis.livejournal.com/39586.html

Earthlings

A couple of months ago, in the middle of December last year, just before "Mayan doomsday" on the 21st, my favorite text editor asked me to approve its regular update. I clicked the link to see what's in the new package, and it immediately redirected me to the page describing new features and fixes. My fellow software developer of great Notepad++, Don Ho*, conveniently named the update "New release (v6.2.3)—End of the World Edition". It brought a series of chuckles to my face that simultaneously morphed into a big smile when I read the description below the title. Referring to the Mayan prophecy, he wrote exactly this: "Even though I don't believe this bullshit, I'm not against resetting our shitty world". Well, I don't know what exactly he meant with the word "reset", but certainly there are days when I can completely agree with him and describe our world exactly the same way.

Viktor and his 6th Earth Day

Anyway, today is another edition of "Earth Day", and at least today we should try and put away all the pessimism (or realism, if you will) and remember those other days capable of filling our lives with at least a small amount of happiness and try to find all the optimistic thoughts we can pack into a message for the future world that will have no need of rebooting itself every now and again. Those who follow my blog probably know that my son was born on Earth Day, so I have another reason to celebrate today. He is turning 6 years old, and recently his childhood has been successfully extended with his first year of school, lots of new friends, and his first new obligations. I can see he is exiting with all the changes, and I truly envy him. Childhood is something special. Every day is bringing something new, and the empty bucket in his head is permanently filling slowly and inevitably. Also, a child's mind is pure and not burdened with adult stuff. I can't remember exactly in which episode, but I think Yoda once said, "Truly wonderful the mind of a child is", when he was trying to explain how children perceive reality very differently and sometimes much better than adults. We simply tend to complicate the world around us without any possible need.

Just to prove my point, let me add a small glimpse ofone of our annual things we do. My wife is a schoolteacher, and with other teachers, every year she is taking her class to the nature resorts, usually mountains, for one week. Viktor and I hook along every year and spend wonderful time with hundreds of other children. Believe me or not, these weeks recharge my batteries better than any vacations at the seaside or any holiday days off. During these weeks, the adults are severely outnumbered, and you can feel it. The air is always full of joy, optimism, happiness, and pure enlightenment. This week is one of those weeks. I took days off and drove six hours to this distant mountain in western Serbia to join the class, and the feeling is again there. Even at this very moment while I am writing this sitting alone in our hotel room, children are loudly singing in the discotheque situated a floor above, and I don't mind at all. Just the opposite. Silence would be disturbing.

Neil deGrasse Tyson**

Sometimes I truly wonder what goes wrong with people when they grow up. Why do they change that much over time? I don't know. Is it in our genes, written somewhere, how to spoil all the magic happening in the first decade or two of our lives, or is the society we live in the one to blame? I don't think anybody has a valid answer, so I will just quote my favorite astrophysicist, Neil deGrasse Tyson, who once said, "Children do not read horoscopes. Children are perfectly happy counting through the number 13. Children aren't afraid to walk under ladders. They see a black cat cross their path, and they say, 'Look! Kitty, kitty,' and want to pet it, not run in the other direction. Children are not the problem here. You say you’re worried about children? I’m not worried about children; I’m worried about 'grown-ups'. Kids are born curious. They are always exploring. We spend the first year of their life teaching them to walk and talk, and the rest of their life telling them to shut up and sit down." Keeping all those optimistic words like this one in mind and also all those pessimistic tales like the one from the beginning of this post, I decided to use suitable wallpaper I found online and put it as the background of the montaged image honoring this year's Earth Day and, of course, Viktor's 6th birthday. The image represents two very distant parts of humanity, or, metaphorically speaking, the dark and Jedi parts of the world as we know it. Of course, in the middle is one of Viktor's most cheerful recent photos with a clear message representing the innocent childhood of all Earthlings out there.

This year Earth Day 2013 is themed as "The Face of Climate Change". I am sure our planet, looking at her as a living organism, has her own cycles and climate changes that are sometimes simply unavoidable events, but humans over the years have grown up to the point of being a big player, fully capable of selfishly contributing and producing climate changes of their own. Following the motto where one picture is worth a thousand words, please see the official video:


"Climate change has many faces. A man in the Maldives worried about relocating his family as sea levels rise, a farmer in Kansas struggling to make ends meet as prolonged drought ravages the crops, a fisherman on the Niger River whose nets often come up empty, a child in New Jersey who lost her home to a super-storm, a woman in Bangladesh who can’t get fresh water due to more frequent flooding and cyclones… And they’re not only human faces. They’re the polar bear in the melting arctic, the tiger in India’s threatened mangrove forests, the right whale in plankton-poor parts of the warming North Atlantic, the orangutan in Indonesian forests segmented by more frequent bushfires and droughts"

I've already posted about this topic, and if you are eager to learn more about Earth Day and Biodiversity, please follow the blue links. The problem is not only complex, but also, even though awareness is there, the solution seems to be as far as the distance from here to the horizon itself.

Divčibare, Crni Vrh, 1098m

Are we too late to act and already stepped over the edge? I don't know, but like today when I am in the company of one hundred and thirty children visiting the highest peak of the mountain 'Maljen' near to the small ski settlement called 'Divčibare' and looking at the world with children's eyes, I have little faith.

*Don Ho
http://notepad-plus-plus.org/contributors/author.html

**Neil deGrasse Tyson
http://www.youtube.com/watch?v=vDFgLS3sdpU
http://en.wikipedia.org/wiki/Neil_deGrasse_Tyson

Earth Day 2013: The Face of Climate Change
http://www.earthday.org/2013/about.html

Divčibare
http://en.wikipedia.org/wiki/Divcibare