Friday, September 21, 2012

Global Warming Made Easy

Major Points of this Blog Post 

The main points of this post are as follows.  Supporting graphs and figures follow below (click on any to enlarge).
  1. In the past 50 years, atmospheric carbon dioxide has increased from about 0.032% to 0.038%.  That's 380 parts per million or still an exceedingly small number.  It still causes warming, let's be truthful.  Your exhaled breath has 100 times that carbon dioxide at 4.0%  or 40,000 parts per million for comparison.
  2. Yes, the Earth has warmed about 0.9 deg C or 1.6 deg F during the past 100 years, which shouldn't cause panic at this time.  Yes, man is causing it
  3. There is more warming in the higher Northern latitudes--including the Arctic and Greenland---than anywhere else.
  4. There are natural variations in the Earth's orbit that cause regular ice ages and warming periods.  We're in a natural warming cycle now and have been for 20,000 years.  Sure, man's CO2 emissions are causing the gradual warming over the past 100 years. 
  5. Sea levels are rising about 0.2 cm per year (about 1/10th of an inch per year).   To put that in perspective, the sea has risen 400 feet in 20,000 years, since the peak in glaciation at that time.
  6. The permanent ice in the Arctic sea in the summer is becoming significantly smaller.  Of course the Arctic sea re-freezes each winter.
  7. The main Antarctic ice cap is stable or possibly increasing in extent and volume.   The Antarctic contains 70% of all fresh water on the planet.  
  8. Greenland's Ice cap is melting due to the warming Arctic temperatures -- which is worrying.
  9. The Ocean will ultimately absorb all of the emitted carbon dioxide, but the absorption rate is about 1/3 the rate of our emissions.  This means that we would have to reduce CO2 emissions by 65% to just to halt CO2 accumulation in the atmosphere.   Cap and trade does not reduce emissions.  CO2 levels will rise unless CO2 emissions are reduced by 50 to 60%.  Cap and Trade doesn't reduce emissions at all.
  10. The cost to reduce CO2 emissions is so high that it will not be done.   The cost to mitigate the effects of rising sea levels, varying temperatures and climate effects is much cheaper and easier to do.
Why Are There Ice Ages (and Natural Climate Changes)?

A Serbian scientist named Milutin Milankovitch quantified long-cycle variations of the earth's orbit around the sun.   From the excellent NASA website, the orbit variations are of three types:  
  1. The circle around the sun becomes more oval and less circular (and back to circular).   This cycle is about 100,000 years long.   This means the Earth moves closer to the Sun at times when it's orbit is more "elliptical."
  2. The seasonal tilt of the Earth varies over 41,000 years between 22 deg and 24 degrees. The less the tilt, the less solar radiation at the higher latitudes.
  3. The Earth wobbles on it's axis (like a wobbly top) with a cycle lasting 19,000 to 23,000 years.
Based on the orbital variations, Milankovitch predicted that the ice ages would peak every 100,000 and 41,000 years, with additional “blips” every 19,000 to 23,000 years.   This is all verified by tree rings, coral reefs, sea levels, glacial extent, etc.

What this means is that there are regular periods of reduced solar radiation and cooler temperatures in higher latitudes that allow winter snowpack to persist through the summer months.  Once snow pack persists over the summer, it increases in extent and forms a "micro-climate" that reinforces the stability of the growing snow fields.  Snow fields become glaciers.   There you go, that's why there are ice ages:  it's the effect of Milankovitch cycles! 

Carbon Dioxide Accumulation in Atmosphere

Figure 1. From NOAA station at Mauna Loa, Atmospheric carbon dioxide levels in the atmosphere from 1958 to present.
Data is presented in parts per million (ppm) and shows a rise of carbon dioxide from 315 ppm to 385 ppm or 0.0385%.   Exhaled human breath has about 4.0% carbon dioxide or 40,000 ppm.   Although the amount of carbon dioxide in the air is still extremely low, it thought by most that this is causing a warming of the Earth's atmosphere.  It is absolutely true that higher CO2 levels in an atmosphere cause a "greenhouse" effect--just how much extremely low levels of CO2 is subject to debate. 

Carbon Balance For The Earth


Figure 2.  Worldwide carbon balance in gigatons per year (from Howard Herzog at MIT, 2001)
The use of fossil fuels is adding 6 gigatons per year (Gt/y) of carbon to the atmosphere.   Another 1.4  Gt/y  is being added by "changing land use" (presumably burning forests).   The ocean is absorbing 2.2  Gt/y, plants are absorbing 1.7  Gt/y  and land is absorbing 0.3  Gt/y .  In total, 3.5  Gt/y  of carbon are accumulating in the air.  This means that fossil fuels use (or emissions) must drop over 50% to halt the accumulation of carbon dioxide in the atmosphere.   That would a monumental task and would be hugely expensive.

Global Temperatures in Modern History

Figure 3.  Global Land-Ocean Temperature index (From www.newscientist.com. and others.)
This data shows that the earth's surface has warmed by 0.9 degrees Celsius or 1.6 degrees F since 1910.  It also shows a period of temperature stability between 1880 and 1920.   The 1880s was considered a "mini-ice age" due to colder conditions. 




Figure 4.  Earth's Temperature Record from nasa.gov
Shows the record of temperatures in both the Northern and Southern Hemispheres.  The Southern Hemisphere hasn't warmed quite as much as the Northern Hemisphere presumably due to predominance of the oceans.   There appears to be quite an acceleration of temperature rises in the Northern Hemisphere.



Figure 5.  Surface and Satellite Temperature Data (from global-warming-and-the-climate.com)
The data from 1975 to 2010 is variable but shows about 0.4 deg Celsius rise or 0.72 deg F.

Figure 6.  Temperature Record by Latitudes (both North and South) (from nasa.gov)
The data shows that the Northern higher latitudes are warming disproportionately compared to equatorial and southern latitudes.   In other words, the Arctic areas are warming the most and this is reflected in Arctic ice melting and the melting of permafrost in Siberia and Arctic areas.




Sea Level Records


Figure 7.  Recent Sea Level Rise (from window2universe.org)
The surface observations show a 20 centimeter rise of the sea from 1900 to 2000 or  0.2 centimeter per year or about 0.08 inches per year (call it 1/10th of an inch per year).   20 centimeters is about 8 inches.  

Figure 8 Sea Level Data
(From University of Colorado at Boulder and CSIRO-Commonwealth Scientific and Industrial Research Organisation  www.cmar.csiro.au/sealevel)  

Shows basically the same information as Figure 7 or about 8 inches of sea level rise in about 100 years.


Figure 9 Sea Level Data Showing possible acceleration of sea level change (from  worldviewofglobalwarming.org)
2 mm/year is the same as 0.2 centimeter per year or the same as Figure 7.  But the Univ of Colorado has drawn in a higher rate of rise of 3 mm//year in recent years.

Figure 10 Long Range Sea Level Change (from climatesanity.wordpress.com)
This figure shows a notional 120 meter or 400 feet sea level rise since the peak of the last ice age dating back 20,000 years ago.

Antarctic Sea Ice Extent 

Figure 11 Antarctic Ice Extent from late 1970s to Present
The Graph shows that the Antarctic Ice Extent is steady or slightly increasing.  All of the data must be  normalized because of the melting of sea ice around the continental ice.  See Figure 13 for actual ice extent fluctuations including seasonal fluctuations.



Figure 12 Antarctic Ice Extent (from worldclimatereport.com)
This is the same data as shown in Figure 11 showing the Ice extent increasing slightly, but look at Figure 13 for more raw data.

Figure 13 Total Antarctic Sea Ice Extent (from nsidc.org--National Snow and Ice Data Center)
This graph shows the seasonal variations of sea for the past 30 years.   There is no apparent trend of sea ice extent in the Antarctic.  The Antarctic ice cap is not melting.  Since the Antarctic ice cap is 70% of the earth's fresh water, this is good news.

Figure 14 Sea Ice Extent April 2009 (from National Snow and Ice Data  Center)
Shows the ice extent in April 2009 which would be the end of the Antarctic summer and also shows the median extent during the period 1979 to 2000.


Figure 15 Antarctic Ice Extent July 2012 (from National Snow and Ice Data Center)
Another snapshot of ice extent in mid-winter of 2012 and median extent over recent decades.

Arctic Ice Extent 

Figure 16 Arctic Ice Extent (from NSIDC)
Shows considerable end-of-summer sea ice melting in the Arctic compared to historical extent.


Figure 17 Arctic Ice Extent (NSIDC)
This data shows the seasonal ice extent in the Arctic for the past 30 years.  The trend is obviously declining in the Arctic (unlike the Antarctic in Figure 13)
Greenland Ice Cap

The Greenland Ice Cap is part of the Arctic Ice Sheet.  And the data is worrying here.  From NSIDC

The mass of ice in the Greenland Ice Sheet has begun to decline. From 1979 to 2006, summer melt on the ice sheet increased by 30 percent, reaching a new record in 2007. At higher elevations, an increase in winter snow accumulation has partially offset the melt. However, the decline continues to outpace accumulation because warmer temperatures have led to increased melt and faster glacier movement at the island's edges.
From CIRES/University of Colorado, Konrad Steffen,

The Greenland Ice Sheet dominates land ice in the Arctic. Maximum surface-melt area on the ice sheet increased on the average by 16% from 1979-2002 (Steffen et al., 2004)
Ok, Greenland ice melting is one of the more worrisome areas of the Global warming saga as it's a huge amount of water that will affect the sea level.

Carbon Capture Costs Vs Mitigation Costs

I can say almost for sure that there will be no carbon capture and sequestration to reduce greenhouse gas emission. It's insanely expensive!   

After decades of alarm-ism, there is still not one power plant with carbon capture in existence in the world--anywhere in the world! The US has 10,000 power plants alone. We don't even know exactly how best to do it. I figure that it would cost $10 trillion dollars to electrify automobiles, scrub power plant flue gas to remove and sequester carbon dioxide, build nuclear and wind power plants to power the cars in the US. Even this would only reduce CO2 emission by 50%. This would have to replicated around the world just to steady carbon dioxide concentration in the atmosphere at a cost of $40 trillion. It just won't happen. Period. Remember, after $40 trillion, CO2 in the atmosphere would not decrease---it would remain elevated. So, presumably temperature rises would stabilize at the higher level.

It would make more sense to use US natural gas in a nationwide push for CNG buses and mass transit to reduce our carbon footprint.  It makes economic sense.  I believe that if buses came every 3 to 5 minutes, people would use them and relinquish personal automobiles. This in combination with increased gasoline taxes would be very effective at curbing CO2 emissions. This is much more practical. Where's this debate in the media? Where is our Energy Department on this subject? Why do we even have an Energy Dept? They can't do anything!

It will take billions, not trillions to build seawalls or gradually relocate coastal cities to higher ground. I don't believe there is an immediate panic in terms of ocean levels but it's worth keeping an eye on.

The cost of mitigating the effects of possibly higher temperatures (if they come to past) will be infinitely less costly than carbon capture and sequestration.

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