<blockquote>
<p>It thus seems reasonable to say we are entering another Ice Age according to Milankovitch cycles.</p>
</blockquote>
<p>Some of the Milankovitch conditions would appear to make the Earth ripe for a new glacial epoch starting now, or perhaps a few hundred years ago. In particular, aphelion occurs in early July, and obliquity is low. Both of these make for mild northern hemisphere summers, a key condition needed for snowfall from the previous seasons to linger into fall.</p>
<p>But one other key Milankovitch condition needed to make snowfall linger, orbital eccentricity, argues against a new glacial epoch starting now. The low (and decreasing) eccentricity makes the current dip in summertime insolation at high northern latitudes too small of a dip to trigger the onset of an glacial epoch. Look at the graph you posted in your question. Glacial epochs start when summertime insolation at high northern latitudes drops to very low values. The current local minimum is not low enough to enable widespread accumulation of snow and ice over the summer.</p>
<blockquote>
<p>Some of you may cite the current anthropogenic climate change as a rebuttal, but for the question's sake, just ignore it.</p>
</blockquote>
<p>Even without anthropogenic help, the current interglacial is likely to last for 50,000 years [Berger and Loutre]. With anthropogenic help, the current interglacial may even last indefinitely [Steffen].</p>
<blockquote>
<p>Throughout geological history, Earth has seen far lengthier and more widespread glacials than interglacials. Indeed, interglacials are just short blips in the geological history.</p>
</blockquote>
<p>That is true only for last 2.58 million years, possibly the last 34 million years. The Earth has been ice-free for most of the last 550 million years. Ice ages (periods during which ice can form, intermittently, are just short blips.</p>
<br>
References:
<br>Berger, André, and Marie-France Loutre. "An exceptionally long interglacial ahead?." Science 297.5585 (2002): 1287-1288.
<br>
<br>
Steffen, Will, et al. "Trajectories of the Earth System in the Anthropocene." Proceedings of the National Academy of Sciences 115.33 (2018): 8252-8259.

CC BY-SA 4.0
2020-07-15T16:42:43.500Z
2020-07-15T16:42:43.500Z
David Hammen
<p>Milankovitch cycles consist of three orbital parameters: eccentricity, obliquity, and precession of equinoxes.</p>
<p>According to Milutin Milankovitch, the most recent glacial period ended nearly 11,000 years ago, when combination of eccentricity, obliquity, and precession at that time strongly favored deglaciation in the northern high latitudes. Specifically, eccentricity, moving on cycles of 100,000 years, was slightly larger than it is today, and Earth was slightly elliptical than it is today. Obliquity, moving between 22.1 and 24.5 degrees, was nearly at its maximum 11,000 years ago. And precession was pointing at Vega.</p>
<p>It then goes that this combination of orbital parameters enabled the northern hemisphere to experience its summer solstice at the perihelion, which gave the northern hemisphere the largest possible solar radiation on any summer solstice positions. And obliquity was at its maximum, significantly reducing the size of polar regions shielded from solar radiation between the spring and fall equinoxes in the northern hemisphere. So the northern high latitudes experienced a high volume of incoming solar radiation that allowed snow accumulation rate to fall below that of snow melting. Thus, the most recent glacial period started to end.</p>
<p>But now, 11,000 years after the last glacial period, the combination of orbital parameters changed a lot. Eccentricity is near its lowest, making the total solar radiation on Earth at perihelion and aphelion closer than ever. Obliquity is midway between the maximum and the minimum, shielding a significant area of the polar regions from incoming summer sunlight. And precession is now pointing at the Polaris, the exact opposite of Vega. This combination allows the northern hemisphere to experience its summer solstice at the aphelion, and winter solstice at the perihelion, which significantly curtails the amount solar radiation in the northern hemisphere. The northern high latitudes now are shielded more from solar radiation between the spring and fall equinoxes. These new changes seem to make Earth go in the direction of another glacial period, because snow melting seems to be slowing in the northern high latitudes and snow accumulation quickening.</p>
<p>Throughout geological history, Earth has seen far lengthier and more widespread glacials than interglacials. Indeed, interglacials are just short blips in the geological history. It thus seems reasonable to say we are entering another Ice Age according to Milankovitch cycles.</p>
<p><a href="https://i.sstatic.net/jmkpi.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/jmkpi.jpg" alt="Glacials and Interglacials in Earth's History" /></a></p>
<p>Some of you may cite the current anthropogenic climate change as a rebuttal, but for the question's sake, just ignore it.</p>

CC BY-SA 4.0
2020-07-15T12:34:01.490Z
This is a looooong way to ask a simple question... You don't need to explain what Milankovitch cycles are, it's better to go straight to the point.
Jean-Marie Prival
CC BY-SA 4.0
2020-07-21T02:15:36.093Z
note it would not be a new ice age, but a new glacial period in the current ice age we are still in.
John
CC BY-SA 4.0
2021-05-20T15:44:23.907Z
I just noticed, on google, there are many click baits and contradicting article titles, one that contradicts user20217's answer.
Tardy
<climate><earth-history><milankovitch-cycles><axial-obliquity>
Are we entering a new Ice Age according to Milankovitch cycles?
seamos
# Are we entering a new Ice Age according to Milankovitch cycles?

(Asked by: username_0 on 2020-07-15)

Milankovitch cycles consist of three orbital parameters: eccentricity, obliquity, and precession of equinoxes.

According to Milutin Milankovitch, the most recent glacial period ended nearly 11,000 years ago, when combination of eccentricity, obliquity, and precession at that time strongly favored deglaciation in the northern high latitudes. Specifically, eccentricity, moving on cycles of 100,000 years, was slightly larger than it is today, and Earth was slightly elliptical than it is today. Obliquity, moving between 22.1 and 24.5 degrees, was nearly at its maximum 11,000 years ago. And precession was pointing at Vega.

It then goes that this combination of orbital parameters enabled the northern hemisphere to experience its summer solstice at the perihelion, which gave the northern hemisphere the largest possible solar radiation on any summer solstice positions. And obliquity was at its maximum, significantly reducing the size of polar regions shielded from solar radiation between the spring and fall equinoxes in the northern hemisphere. So the northern high latitudes experienced a high volume of incoming solar radiation that allowed snow accumulation rate to fall below that of snow melting. Thus, the most recent glacial period started to end.

But now, 11,000 years after the last glacial period, the combination of orbital parameters changed a lot. Eccentricity is near its lowest, making the total solar radiation on Earth at perihelion and aphelion closer than ever. Obliquity is midway between the maximum and the minimum, shielding a significant area of the polar regions from incoming summer sunlight. And precession is now pointing at the Polaris, the exact opposite of Vega. This combination allows the northern hemisphere to experience its summer solstice at the aphelion, and winter solstice at the perihelion, which significantly curtails the amount solar radiation in the northern hemisphere. The northern high latitudes now are shielded more from solar radiation between the spring and fall equinoxes. These new changes seem to make Earth go in the direction of another glacial period, because snow melting seems to be slowing in the northern high latitudes and snow accumulation quickening.

Throughout geological history, Earth has seen far lengthier and more widespread glacials than interglacials. Indeed, interglacials are just short blips in the geological history. It thus seems reasonable to say we are entering another Ice Age according to Milankovitch cycles.

[![Glacials and Interglacials in Earth's History](https://i.sstatic.net/jmkpi.jpg)](https://i.sstatic.net/jmkpi.jpg)

Some of you may cite the current anthropogenic climate change as a rebuttal, but for the question's sake, just ignore it.

**Tags:** climate, earth-history, milankovitch-cycles, axial-obliquity

> **Comments:**
> **username_1**: This is a looooong way to ask a simple question... You don't need to explain what Milankovitch cycles are, it's better to go straight to the point.  
> **username_2**: note it would not be a new ice age, but a new glacial period in the current ice age we are still in.  
> **username_3**: I just noticed, on google, there are many click baits and contradicting article titles, one that contradicts user20217's answer.  

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## 1 answers

### Answer by username_4 on 2020-07-15. Score: 8

> It thus seems reasonable to say we are entering another Ice Age according to Milankovitch cycles.

Some of the Milankovitch conditions would appear to make the Earth ripe for a new glacial epoch starting now, or perhaps a few hundred years ago. In particular, aphelion occurs in early July, and obliquity is low. Both of these make for mild northern hemisphere summers, a key condition needed for snowfall from the previous seasons to linger into fall.

But one other key Milankovitch condition needed to make snowfall linger, orbital eccentricity, argues against a new glacial epoch starting now. The low (and decreasing) eccentricity makes the current dip in summertime insolation at high northern latitudes too small of a dip to trigger the onset of an glacial epoch. Look at the graph you posted in your question. Glacial epochs start when summertime insolation at high northern latitudes drops to very low values. The current local minimum is not low enough to enable widespread accumulation of snow and ice over the summer.

> Some of you may cite the current anthropogenic climate change as a rebuttal, but for the question's sake, just ignore it.

Even without anthropogenic help, the current interglacial is likely to last for 50,000 years [Berger and Loutre]. With anthropogenic help, the current interglacial may even last indefinitely [Steffen].

> Throughout geological history, Earth has seen far lengthier and more widespread glacials than interglacials. Indeed, interglacials are just short blips in the geological history.

That is true only for last 2.58 million years, possibly the last 34 million years. The Earth has been ice-free for most of the last 550 million years. Ice ages (periods during which ice can form, intermittently, are just short blips.

  
References:
  
Berger, André, and Marie-France Loutre. "An exceptionally long interglacial ahead?." Science 297.5585 (2002): 1287-1288.
  
  
Steffen, Will, et al. "Trajectories of the Earth System in the Anthropocene." Proceedings of the National Academy of Sciences 115.33 (2018): 8252-8259.


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