NH Summer Energy: The Leading Indicator


One purpose of science is to determine the Cause and Effect of a system.  When it comes to climate, that can be difficult as one change can cause so many other changes.  For instance, a change in water temperature causes a change in atmospheric CO2 levels.  That could cause a feedback effect, but it isn’t the cause of the change itself.

Last week I showed that the seasons in the Northern Hemisphere have the biggest impact of the global temperature average.  I also showed how the climate sensitivity could be determined from changes in the summer energy of the Northern Hemisphere (NH).   I might have gotten ahead of myself with that one.  So I will add this article in to show how significantly the current climate of the Earth has been determined by the amount of energy the NH receives from the sun.

The last glacial (ice age) was ending about 17,000 years ago.  The cause of its end was an increase in the solar energy the NH was getting from the sun during the summer months.  This resulted in what is referred to as the Holocene Interglacial.  That is the warm period that we are currently living in.  Here is a chart that shows the temperature of both poles and the amount of energy the NH has been getting during the summer months.

The Inconvenient Skeptic

Green: NGRIP ice core (Greenland), Blue: Antarctic ice core (Vostok), Red: Northern Hemisphere Solar Energy, Summer.

This shows that well before the temperature started to increase in either hemisphere, the amount of energy in the NH started to increase during the summer months.  Since the peak summer energy levels in the NH started dropping 9,000 years ago, the NH has started cooling.  This is shown in all of the NH ice core data.  That is why I show a NH ice core as the chart on the header for this website.

That the NH has been cooling for the past 6,000 years has found new supporting evidence in a recent article (Jakobsson, 2010) that states in the abstract:

The combined sea ice data suggest that the seasonal Arctic sea ice cover was strongly reduced during most of the early Holocene and there appear to have been periods of ice free summers in the central Arctic Ocean.

What an ice free Arctic might look like from space

The ice core data and this most recent article all point to the early Holocene being warmer in the Arctic than it currently is.  A period of warmth like that would have caused more ice melt in Greenland than what is currently taking place.  Almost all claims of the “dangers” of global warming existed in the early Holocene.  What is proposed as being unnatural, just happened a short few thousand years ago.

The counter claim to that would be, “now CO2 levels are high.”  Here is my very simple response to that.

The Inconvenient Skeptic

Summer Energy Leads CO2 Levels

CO2 levels have been increasing (due to warmer ocean temperatures) for thousands of years.  The strong forcing factor of NH summer energy levels has been cooling the NH which has caused the summer Arctic ice to return in the same period that the CO2 levels have been rising.  Much like I have shown before, CO2 has never been able to prevent the Earth from cooling.  The increasing CO2 levels for the past 10,000 years have not prevented decreasing NH temperatures.  Nor is there any indicator that they will be able to in the future.

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Sources:

Vostok Ice Core: Temperature and CO2.

Taylor Ice Dome: CO2

NGRIP: Greenland Ice Core

Northern Hemisphere:  Summer Insolation

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Posted in Climate and Science Articles - Global Warming by inconvenientskeptic on November 1st, 2010 at 6:17 am.

4 comments

This post has 4 comments

  1. Malaga View Nov 2nd 2010

    The Leading Indicator graph is fascinating… the Holocene Maximum, albeit in slow decline, looks like it has been unusually sustained well beyond the downturn in the Summer Solar Energy curve… So I ask myself: Why?

    Looking at the map it seems like the Bering Strait is very narrow ( about 53 miles wide ), very shallow ( average depth of 98–160 feet ) and has a few islands located right in the middle of the Straits.

    So I guess that the opening of the Bering Strait ( in recent geological time ) must have allowed warmer Pacific waters to enter the Artic Basin… and perhaps with each period of Glaciation the depth of the Bering Strait has been slowly increased by striation…

    Do you have any thoughts or comments?

    PS: I have just taken another look at the “Earth during the last glacial” illustration and noticed that the Artic Basin is shown as ICE FREE… really???

    http://theinconvenientskeptic.com/wp-content/uploads/2010/10/Pleistocene-moll_NL.jpg

  2. Malaga View Nov 2nd 2010

    For what its worth… I just came across the follow article:

    Bering Strait influenced ice age climate patterns worldwide
    http://www.physorg.com/news182326598.html

    In a vivid example of how a small geographic feature can have far-reaching impacts on climate, new research shows that water levels in the Bering Strait helped drive global climate patterns during ice age episodes dating back more than 100,000 years.

  3. inconvenientskeptic Nov 2nd 2010

    Malaga,

    Good point about the Arctic. It wasn’t ice free, but the geologist that made this focused on the land sheets. The exact coverage of ocean ice has a bit more speculation attached to it. He has some pretty impressive geological maps.

    Also a good point about small geological changes causing big changes. I have seen many articles about the change between South America and Antarctica changed the ocean currents there and that is also timed with Antarctica freezing solid.

    Anything that changes ocean currents changes climate.

  4. Gene Zeien Nov 2nd 2010

    Malaga View
    Nov 2nd 2010
    Bering Strait influenced ice age climate

    Awesome! All we have to do is close off the Bering Straight & we start the next Ice Age. Installing a few flood gates, similar to those on the Thames in London, and we can control the climate. Wonder how long those gates would last in 6′ of shifting ice…

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