Scientific and Spiritual Dimensions of Climate Change: Class 4

SCIENTIFIC AND SPIRITUAL DIMENSIONS OF CLIMATE CHANGE
A STUDY COURSE 



Class 4

The Causes of Global Warming



“God saw everything that he had made, and indeed, it was very good.” (1) The Bible

“No defect canst thou see in the creation of the God of Mercy: Repeat the gaze: seest thou a single flaw?” (2) The Qur'an

“How great, O my God, is this Thy most excellent handiwork, and how consummate Thy creation, which hath caused every understanding heart and mind to marvel!” (3) Baha'u'llah


Section 1: Scientific Observations of Global Warming and Changes in Climate

Over the past few decades the science of global warming has made much progress. Now, there is certainty that the planet has been warming. Also the estimated likelihood of human beings being responsible for that warming has increased from 90-100% in 2007 to 95-100% in 2013:

“Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased.” (4)

This statement comes from the most recent report by the Working Group 1 of the Intergovernmental Panel on Climate Change, issued on Sept. 30, 2013 and is also included in the Synthesis Report released on Nov. 1, 2014.

Some global warming facts:

  • “The first decade of the 21st century was the warmest on record, according to NASA. (5)
  • Since the Industrial Revolution, global average temperature has increased by about 1°C (1.8°F).
  • “Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010 (high confidence). It is virtually certain that the upper ocean (0−700 m) warmed from 1971 to 2010, and it likely warmed between the 1870s and 1971.” (6)
  • The warming is not evenly distributed. Some areas have warmed much more. Parts of the Arctic have warmed by 2° - 3°C (3.6°-5.4°F) just since the 1950s. (7)

Graph 1: (7A)

Global Temperature showing steady increase in the past decades, compared to 1880-1920 average

As we have seen in the last two chapters, this warming has serious consequences, especially for low-lying areas and poor countries, but in the near future also for all of humanity.


Section 2: What Is Global Warming?

“We, assuredly, have decreed a cause for all things and vouchsafed everything with an effect. All of this is by virtue of the effulgence of My Name, the Efficacious (the 'Producer of Effects') upon existing things. Verily, thy Lord is the One Who exerciseth command over all that He willeth.” (8)  Baha’u’llah

The Carbon Cycle

For the understanding of global warming it helps to have some insight into the carbon cycle: “The biosphere is maintained by a complex set of delicately balanced systems which are still poorly understood. The atmospheric conditions that permit life to exist were themselves created in part by the action of living things. The early plants removed carbon dioxide from the atmosphere and added oxygen, making animal life possible. Dead plants, both the remains of marine plankton and terrestrial vegetation, were buried and fossilized as coal, oil and gas, and their carbonate skeletons became layers of limestone, locking a significant part of the Earth's carbon away in geological formations.
Carbon cycles through the biosphere, as plants take up carbon dioxide to make organic matter, while animals and decomposers return the carbon dioxide to the oceans and atmosphere.” (9)

The Greenhouse Effect:

Atmospheric gases like carbon dioxide (CO2), methane and nitrous oxide are called greenhouse gases because they act similar to the glass in a greenhouse by trapping heat. Or more specifically worded: “the greenhouse gases are transparent to most incoming radiation from the sun, which passes through the atmosphere and hits the Earth. The Earth is warmed by this radiation, and in response radiates infrared (long wavelength) energy back into space. That is where greenhouse gases come into play. These atmospheric gases absorb some of the outgoing infrared radiation, trapping the heat energy in the atmosphere and thereby warming the Earth.” (10) Life on Earth is only possible because of this greenhouse effect. It has kept the Earth’s average surface temperature stabilized at around 13.5°C (56.3°F) for a long time.

Since the industrial revolution, greenhouse gases have sharply increased - upsetting the previously long-lasting balance. Scientists confirm that this increase of greenhouse gases is for the most part anthropogenic (man-made). The increase comes mainly from emissions from power plants, cars, airplanes, deforestation and industrial activities. We are “returning carbon to the atmosphere and oceans that has long been out of circulation.” (11)

The more greenhouse gases there are in the atmosphere the warmer our planet becomes.

A little bit of climate science history

The Greenhouse Effect has been an accepted scientific fact since the 19th century. Already in the 19th and early 20th century, some scientists suggested a possible future global warming caused by human emissions of CO2, but this theory was only confirmed later. Instrumental to this discovery was Prof. Charles Keeling. In 1958, he began daily measurements of CO2 concentrations in the atmosphere. The resulting curve showed a steady increase of CO2 concentrations (see graph 1 below). Each year, there is a temporary decline in the curve: Whenever it is spring and summer in the Northern Hemisphere (which has much more land mass than the Southern Hemisphere), CO2 concentrations in the atmosphere fall, because growing vegetation is taking in more CO2 .

Graph 2: (12)

Many more studies have been done since then. Besides carbon dioxide (CO2 ), the main greenhouse gases are methane (CHO4 ) and nitrous oxide (N2 O). (Water vapor, a naturally occurring greenhouse gas, will be discussed in class 8, section 2.) Scientists collected data on the atmospheric concentrations of these three greenhouse gases during the past 1000 years by studying ice core samples. As you can see on the curves below, for a long time their levels were pretty constant with only minor variations, but then they started to increase dramatically in the 19th century.

Graph 3:

CO2, Methane, and Nitrous Oxide concentrations past 1000 years

This graph shows the increase in greenhouse gas (GHG) concentrations in the atmosphere over the last 2,000 years. Increases in concentrations of these gases since 1750 are due to human activities in the industrial era. (Concentration units are parts per million (ppm) or parts per billion (ppb), indicating the number of molecules of the greenhouse gas per million or billion molecules of air.) (13)

  • Carbon Dioxide (CO2) is emitted primarily by burning fossil fuels and by the clearing of forests. CO2 remains in our atmosphere for many decades and some of it for many centuries and longer.
  • Methane (CH4) is emitted from landfills, coalmines, oil and gas operations, beef production and rice paddies. Methane is a very powerful greenhouse gas. It stays in the atmosphere for about 12 years. Measured over a period of 20 years, methane is 86 times more powerful as a greenhouse gas than CO2, and over 100 years it is about 30 times as powerful. (13A)
  • Nitrous oxide (N2O) is emitted by nitrogen based fertilizers and industrial activities. It stays in the atmosphere on average for 114 years.

“The atmospheric concentrations of carbon dioxide (CO2 ), methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. CO2 concentrations have increased by 40% since pre-industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions. The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification.” (14)

We should also be aware of another category of greenhouse gases, the Fluorocarbons or F-gases. Chemical engineers have designed these gases specifically to trap heat. That’s why they are very powerful greenhouse gases. These chemicals are used mainly “in refrigeration and air conditioning, but also as solvents, as blowing agents in foams, as aerosols or propellants, and in fire extinguishers. The Intergovernmental Panel on Climate Change calculated that the cumulative buildup of these gases in the atmosphere was responsible for at least 17% of global warming due to human activities in 2005. The most commonly used F-gases are the hydrofluorocarbons (HFCs). HFCs were developed by the chemical industry in response to the discovery of damage to the Earth’s ozone layer due to chlorofluorocarbons (CFC) use. But this development ignored the known global warming effect of the newer chemicals. Fortunately, there are environmentally safe, efficient, technologically proven, and commercially available alternatives to F-gases in almost all domestic and commercial applications.” (15) The chemical industry has so far resisted the use of these natural alternatives. As many F-gases stay in the atmosphere for a very long time, it is extremely important that we discontinue their use and production.


Watch this video:

Climate Change 2013: The Physical Science Basis  9 min.
https://www.youtube.com/watch?t=28&v=6yiTZm0y1YA


Section 3: A Look into the Past

“Science is the discoverer of the past. From its premises of past and present we deduce conclusions as to the future”. (16) 'Abdu'l-Baha

Looking back into the more distant past we know that there have been natural cycles of warming and cooling. The Earth went through many ice ages and interglacial periods. British scientists drilled three kilometers deep into the Antarctic ice and measured gas concentrations in pockets of air that have been trapped in the ice for thousands of years. From the analysis of the ice cores they could figure out the temperatures and CO2 concentrations of the past 400,000 years:

Graph 4: (17)

CO2 and Temperatures over past 400,000 years, Vostok

Let us first look only at the temperature changes shown by the red (higher) curve. The areas with low temperatures signify ice ages; the peaks going up signify the briefer interglacial periods. The last dip down on the right shows the last ice age more than 10,000 years ago. These climate changes were caused by natural factors. The main factors were slight variations in the earth’s rotation, namely the cyclical changes in the tilt of the Earth’s axis of spin and the shape of the Earth’s orbit around the sun. Solar variation and volcanic eruptions played a minor role as well.

Now, let us look at the CO2 concentrations, which is the blue (lower) curve. You can easily see how similar the two curves are. When temperature is up, CO2 is up and vice versa. Although the graph may look simple, the relationship between CO2 level and temperature is very complex. As we said before, in the past, the reasons for climatic changes were all natural processes, especially shifts in the Earth's rotation. Temperatures affected CO2 levels due to feedback mechanisms (more about that in class 8, section 2). In turn CO2 had an effect on temperature by augmenting the warming or cooling trend. In other words: Without the atmospheric CO2, the changes in temperatures would have been much smaller.

Graph 4 below includes another study. It shows the atmospheric CO2 concentrations over the past 800,000 years. In addition, we can see present (2014/2015) levels.

Graph 5: Carbon Dioxide Concentrations in the past 800,000 years and today (18)

“The atmospheric concentrations of CO2 consistently fluctuated between 200 parts per million (ppm) during the ice ages and 280 ppm during the warm intervals. This shift from ice age to warm period occurred many times and always within thiCO2 range. When the Industrial Revolution began, the atmospheric CO2 level was roughly 280 ppm.” (19)

On the graph we can see that CO2 never went above 300ppm. In 2014, atmospheric CO2 concentrations reached an extraordinary 400ppm! From this and other studies we know that 400ppm “is not only far above any level over the last 740,000 years, it may be nearing a level not seen for 55 million years. At that time the Earth was a tropical planet. There was no polar ice; sea level was 80 meters (260 feet) higher than it is today.” (20) Let's put the number of 740,000 years into proper perspective. What we consider human civilization doesn't extend farther back than 10,000 years. At that time a relatively warm and stable climate emerged which allowed agriculture.


Section 4: The Present and the Future

The situation today is very different from the past’s natural cycles. In a very short period of time, human beings have burnt huge quantities of stored solar energy (fossil fuels), thereby releasing unprecedented amounts of greenhouse gases into the atmosphere. That’s why greenhouse gas concentrations have been so rapidly rising.

The global warming we have already experienced and the many changes in climate all over the world can only be explained by these tremendous increases in greenhouse gases. They cannot be explained by any natural cycle or changes in solar activity or volcanic eruptions. Today, human activities have a stronger impact on climate than natural occurrences: “We have so much CO2 in the atmosphere that its huge radiative forcing overwhelms the changes associated with orbital forcing. No ice age could start at this point!” (21)

If greenhouse gases were held constant at today's level, it is estimated that it would take several decades for their full impact to be felt. The Earth would continue to warm until the climate was in balance with the current greenhouse gases. Unfortunately, CO2 levels are not constant but are continuing to rise which will change the climate and the living conditions on Earth in a very dangerous way.

Review questions on the causes of climate change:

  • What is the “Greenhouse Effect?”
  • Why are global temperatures rising?
  • What are some of the greenhouse gases and where do they come from?
  • What are the reasons for the sudden increase of greenhouse gases since the 19th century?
  • What human activities emit greenhouse gases?

REFERENCES

1. Genesis 1, 31
2. The Qur'an (Rodwell tr), Sura 67 - The Kingdom)
3. Baha'u'llah, Prayers and Meditations, p. 48)
4. Working Group 1 of the Intergovernmental Panel on Climate Change, Report on the Physical Science, Sept. 30, 2013, ex. summary p. 3 and 4
5. http://www.giss.nasa.gov/research/news/20100121/
6. IPCC, Climate Change 2013 – The Physical Science Basis, Headline Statements from the Summary for Policymakers, Sept. 27, 2013 http://www.climatechange2013.org/images/uploads/WG1AR5_Headlines.pdf
7. Arctic Climate Impact Assessment: http://www.ucsusa.org/global_warming/science_and_impacts/impacts/arctic-climate-impact.html#Observed_changes
7A. James Hansen, Global Temperature in 2017, http://www.columbia.edu/~mhs119/Temperature/

8. Baha'u'llah, Provisional Translation of the Lawh-i-Tibb (Tablet to a Physician)‏
9. Arthur Lyon Dahl, Climate Change: Scientific and Faith Perspectives
10. Jeffrey D. Sachs, Common Wealth – Economics for a Crowded Planet, p. 84
11. Arthur Lyon Dahl, Climate Change: Scientific and Faith Perspectives
12. Graph 1: From Noaa’s Earth System Research Laboratory at http://www.esrl.noaa.gov/gmd/ccgg/trends/#mlo_full, taken from http://csas.ei.columbia.edu/2015/08/12/youth-versus-obama-dr-hansens-testimony-against-the-government/
13. http://www.epa.gov/climatechange/science/causes.html This site is no longer available, because “We are currently updating our website to reflect EPA's priorities under the leadership of President Trump and Administrator Pruitt. If you're looking for an archived version of this page, you can find it on the January 19 snapshot: https://19january2017snapshot.epa.gov/climatechange/climate-change-basi…
13A.A http://images.engormix.com/E_articles/0_707.jpg
14. IPCC, Climate Change 2013 – The Physical Science Basis, Headline Statements from the Summary for Policymakers, Sept. 27, 2013 http://www.climatechange2013.org/images/uploads/WG1AR5_Headlines.pdf
15. The Risk of Other Greenhouse Gases by Janos Mate, Kert Davies, and David Kanter, published in “State of the World 2009” by the Worldwatch Institute
16. 'Abdu'l-Baha, The Promulgation of Universal Peace, p. 28
17. http://jules-klimaat.blogspot.com/2009/03/labohm-again-sigh.html and http://3.bp.blogspot.com/-AvHDqDa2Wg0/UIxZFFt2OPI/AAAAAAAABQI/ZfeV13JtSD0/s1600/vostok-temp-vs-co2.gif
18. http://assets.climatecentral.org/images/made/5_2_13_news_andrew_co2800000yrs_1050_591_s_c1_c_c.jpg
19. up-dated from Plan B 2.0 by Lester R. Brown p.592. EPICA Community Members, op. cit. note 1; current carbon dioxide level from C. D. Keeling and T. P. Whorf, “Atmospheric CO 2 Records from Sites in the SIO Air Sampling Network,” in Trends: A Compendium of Data on Global Change (Oak Ridge, TN: Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, May 2005); Brown, op. cit. note 1; Quirin Schiermeier, “A Rising Tide,” Nature, vol. 428 (11 March 2004), pp. 114–15.
20. ibid
21. Rebecca Robinson, Prof. of Oceanography, University of Rhode Island, in an e-mail, Sept. 18, 2008


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Last updated 17 March, 2018

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