Monday, 22 October 2018

Carmarthenshire Flooding, Global warming, and Thermodynamics by Robin Burn










Robin Burn explains the 
science behind the weather.

 President Trump has finally announced his change of mind,on the subject of global
warning, with the caveat that although he nowbelieves it is happening ,but doubts that
 man's interventions are the primary cause.

It may well be he has, along with myself, read the well reasoned article published on line by
 Eric R Pianka (1),  entitled Global Warming.It may also be that President Trump has
acquainted himself with the fundamental laws of physics, that rule everything that happens in
 the universe.

The existence of energy and gravity control the workings of everything that has happened for
 more that 10 billion years, and continues to happen and effect the working of our solar
 system for at least another 4 billion years.That is the length of time remaining until our sun
finally changes into a giant star and engulfs the planets including  our own in its death throws.

Pianka goes on to remind us that physics and chemistry have given us two Laws of
Thermdynamics: the first deals  with conservation of matter, and energy,while the second
 deals with increase in randomness (entropy).

 Pianka is quite firm in his assertiveness when he states, that, whilst some people seem to
think humans are  exempt from physical laws, we are not. An understanding of basic
 thermodynamics is essential to grasp the full  implications of energy usage by humans.

The first law"conservation of matter and energy" states that matter and energy cannot be
created or destroyed. Matter and energy can be converted from one form into another, but
the total of the equivalent amounts of both must always remain constant. Light can be
changed into heat,kinetic energy,and /or potential energy.

Whenever energy is converted from one form or another,some of it is given off as heat, which
is the most random  form of energy. Use of any form of energy produces waste heat.Unless
 this waste heat can be dissipated, temperature rises.

The only energy conversion that is 100 per cent efficient is conversion to heat,or burning.
 Dried organisms can be burned in "bomb calorimeters" to determine how much energy can
 be stored in their tissues. Energy can be measured in a variety of different units, such as
ergs, or joules,but heat energy or calories is the common  denominator. 

Solar energy falls on Earth's surface at any given place and time,creating heat.Unless this
same amount of heat is  dissipated back into space, Earth will warm. Conversely, if more heat
 is re-radiated back out into space than is  received , the planet cools down.

Earth's atmosphere used to be in a complex equilibrium. Certain gases in the atmosphere,
especially carbon dioxide prevent re-radiation of longer infrared wavelengths generated by
incident radiation,holding heat in, thus warming the planet ,the so called greenhouse effect.

The concentration of carbon dioxide has risen steadily over the last 40 years, and continues
to rise due to deforestation and burning of fossil fuels. Global warming could have arrived
sooner except for an increase in particulate matter increasing atmospheric pollution between
1940-1970,allowing less solar energy to penetrate to the surface. The balance shifted during
the 1970's enhancing the greenhouse effect leading to rapid global warming.

.
Up until approximately 10,000 years ago the earth was generally in thermal balance , the
glaciation or cooling  period, and deglaciation, the warming period creating the thermal
balance, happening approximately every 100,000  years.The alterations in the earths orbital
distance from the sun, Milanovitch cycles, as well as slight changes of the  earth's angle of tilt
 away from the vertical, were responsible for the periodic glaciation and deglaciation.

The event 10,000 years ago is significant in as much as this was considered to coincide with
agriculturisation of human activity. Deforestation was the key process of this change of human
 activity from being hunter gatherers to farmers..

As an aside from 1620 onward with the advent of European colonisation of the Northern
 American landmass, mass deforestation has removed nearly all of the virgin forest
.
During the glaciation /deglaciation periods, methane, a greenhouse gas, was either trapped,
 or contained during  the glaciation period, and subsequently released during the deglaciation
 period.

Now because of the consequence of global warming over the last 10,000 years, accelerating
 from deforestation, and enhanced over last 200 years of industrial activity worldwide, more
 trapped methane is being released ,contributing to an ever acceleration of global warming.

It well be the result that the tipping point is unfortunately behind us and reversal of global
 warming unobtainable . The world human population now exceeds 8 billion, and the rise is
 accelerating. Industrialisation is  generating increasing global wealth, leading to this human
population expansion,creating the need for ever growing resource usage. Energy to support
this growth is now being generated by the switch from carboniferous use to natural
occurring solar, wind, and hydro energy. However the ability to do this depends on the ever
increasing usage of the  power plant and the need to replace redundant carbon burning power
 stations.

Unfortunately until the industrial nations can generate enough  power from solar, wind and
hydro stations, we have  to continue with the usage of fossil fuels to supply the building of non
carbon using power plants to replace fossil fuel usage.

A radical change of thinking is required. For instance the increasingly popular carbon dioxide
 removal from the atmosphere  concept will not be possible in the short term due to the
amounts needed to be removed, removal of gigatons of carbon dioxide is not energetically
feasible.

The world needs to consume less energy.

A recent report that the creation of ultra large solar energy farms in the sub Sahara regions
 has actually altered the  local climate. More rain is falling in the regions where solar farms
 exist allowing for revegetation. and food  production.

Acknowledgements;
(1.) Eric R Pianka; Global Warming www.zo.utexas.edu/courses/thoc/Global-Warming.htm

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