Our awesome God!

Our God is an awesome God.  A God of power and majesty!

Science tells us about the events that have caused the world to be the way it is today. I believe the things that science tells us. Geology, physics, cosmology, biology. I understand them. I accept the evidence and the conclusions. The Bible story of creation, I do not believe.  They are the tales of people who, long ago, did not know how the universe works. They are simplistic explanations.  However, none of these facts threaten God.  To me, what science reveals actually magnifies the power of our awesome God.  Our God is not a man working day by day to create a single planet in just six days and, in doing so, becoming so exhausted that he has to rest for the seventh.

There are so many things that have to be just right for us to exist and I think it unreasonable to attribute these to blind chance.

Firstly we live in a universe where the laws of physics allow complex matter to exist.  Change just a few of the basic constants of the laws our universe follows and energy could not give rise to matter or, if it did, it would not be the matter that makes the universe we see. Alter the power of gravity slightly and there would be no condensation of matter into stars. The universe would be filled with simple matter, floating in the void.  We are made of star dust, every single one of us. Without stars there would be no complex atoms that make up the molecules of everything from the atmosphere, to bacteria, to mice, to men. It is within the nuclear furnace of stars that our constituent atoms were made.  Even if gravity was the same, change the energies of the constituents of atoms and nuclear fusion would not occur. We would have condensed matter forming giant blobs. Black holes travelling through space, devouring the rest of the matter that did exist. Without the laws of physics, as they exist, no nuclear fusion means no complex atoms, means no life, no us.

We have observed planets around other stars,  there is no law that says that planets should be ordered as they are in our solar system: Rocky inner planets with massive gaseous outer planets. Other systems have things the other way around, with massive planets, larger than Jupiter, orbiting their stars so closely as to be boiling hot, instead of being out in the cold as our Jupiter is.  Our beautiful Earth is a Goldilocks planet.  Like baby bear's porridge, it is just right.

Complex life depends upon water.  Despite what science fiction writers have said, that statement isn't just a lack of imagination. It is a fact.  It is possible that lifelike processes could occur in other chemical media but other substances tend to liquify at much lower or higher temperatures than water. At lower temperatures chemistry itself slows down.  The available energy is much less than at the temperature at which water is liquid. Some form of life might exist in very low temperatures but it would progress so slowly that it would not become advanced in the period that the universe has existed.  At too high a temperature chemical bonds are too unstable. A living being has to be able to maintain its own integrity and be able to pass on information to the next generation.  Higher temperatures make this far less likely to happen.  Heat is energy.  Make bonds too energetic and they are unstable.

So, life needs liquid water. Water is only liquid at a short range of temperatures.  Too low and it freezes into a solid, in which chemical reactions are too slow.  Too high and water vapourises. No longer liquid, it can not be the medium in which chemical reactions occur.  Our Earth is in just the right place to maintain liquid water on most of the surface. Any closer to the sun and the seas would boil. Any further out and they would solidify.

Our planet is just the right size too.  If the Earth was smaller then its gravitational field would not be strong enough to hold on to an atmosphere.    Unless they are at absolute zero (-460F) all molecules are in motion.  High up in the atmosphere fast moving molecules can reach escape velocity and shoot off into space.   Escape velocity is the speed at which something has to travel in order to leave a planet. That speed depends on the gravity of an object, which depends on its mass.  A smaller planet, composed of the same elements as the Earth, would have a lower mass, a lower gravitational field and, therefore, a lower escape velocity.  It's atmosphere would boil away. Just as that of Mars did.   A planet could have the same mass as the Earth and be smaller but that would mean that it would have to be composed of different materials. If it only contained the heavier elements then it would not contain those required for complex life.  A planet with a larger mass than the Earth has a greater gravity.  It will, therefore, accumulate a larger atmosphere, like the familiar gas giants of our own solar system. This will include the heavier gasses like Carbon dioxide.  Such a planet would have a higher greenhouse effect and thus higher surface temperatures such as those found on our sister planet Venus.  Geologists also theorise that a rocky planet, larger planet than the Earth, would have too thick and rigid a crust to allow plate techtonics.  With no wandering, colliding plates there would be no mountain building, no erosion and complex chemical interactions between the materials of the crust and the atmosphere. Such a planet would not only have greater zoning of elements into layers within its rocky body but also rock and atmosphere would be separated by ocean.

Our planet has just the right amount of Carbon dioxide in the atmosphere to make Earth habitable for complex living things such as ourselves.  Much more and the Earth would experience a run-away warming, similar to Venus. Much less and we would enter an ice age.

The Earth's orbit is virtually (but not quite) a perfect circle around the sun. This is true of most of the planets in our solar system.  Mercury is the exception.  Orbital eccentricity is measured on a scale of 0 to 1. With 0 being a perfect circle. That is, at all times of the year a planet with an orbital eccentricity of 0, is the same distance from its star.  The Earth's eccentricity is 0.017. That of Mercury 0.206.  Of the 1,000 or so planets detected outside our solar system, the large majority have much more eccentric orbits, many with eccentricities greater than 0.3.  This means that the temperature on the planet's surface would vary greatly between closest and furthest approach. Summers would be incredibly hot and winters terribly cold.  Life, particularly complex life, would have a tough time on such a planet.

Jupiter is in just the right place and acts as the guardian of the Earth.  In the majority of the other solar systems where planets have been discovered, the large gas giants are close to their star.  They zip around it in a few days rather than the 12 Earth years that Jupiter takes to go around our sun.  In its distant orbit, Jupiter acts a gatekeeper. There are all sorts of giant lumps of rock and ice travelling around space at high speeds. If they reach the inner solar system then they can hit the Earth.  Some do get through but most that do are small.  The majority of the large rocks out there get picked up by the massive gravitational pull of Jupiter and destroyed long before they threaten us.  The Earth has been hit many times.  However, it would be much worse without the protection of Jupiter. Constant bombardment with asteroids that rework the surface of a planet, is not conducive to the continuation of life on Earth.

I can not believe that all these things are mere chance.  One or two occurring together could be coincidence.  I therefore believe that, taking all these things together,  it is reasonable to conclude that we exist because our place in the universe was deliberately chosen for us, by our amazing God.

Climate change\Global warming Denier Myth Busting 2. Attempting to spread truth.

"Global warming is a recent hoax, a con trick, designed by lying climatologists to get funding." bleat the deniers.

Not so and any such accusation is the result of ignorance or deliberate deceit.

Any rational study of the historical evidence shows a growing worry, about the influence of CO2, among people who had no vested interest in over-hyping the problem:

1896 Svante Arrhenius (1859–1927), Swedish physical chemist and 1903 Nobel laureate, publishes first calculation of global warming from human emissions of CO2.

1938 English engineer Guy Callendar argues that CO2 greenhouse global warming is underway. Published 10 major scientific articles, and 25 shorter ones, between 1938 and 1964 on global warming, infra-red radiation and anthropogenic carbon dioxide.

1956 Canadian Gilbert Plass calculates that adding CO2 to the atmosphere will have a significant effect on the radiation balance.

1957 American Roger Revelle finds that CO2 produced by humans will not be readily absorbed by the oceans.

1960 Charles Keeling accurately measures CO2 in the Earth's atmosphere and detects an annual rise.

1963 Calculations by Fritz Möller suggest that feedback with water vapor could make the climate acutely sensitive to changes in CO2 level.

Same year meeting on “Implications of Rising Carbon Dioxide Content of the Atmosphere” was convened by the private Conservation Foundation.

1965 U.S. President’s Science Advisory Committee reported that “By the year 2000 the increase in atmospheric CO ... may be sufficient
to produce measurable and perhaps marked changes in climate...”

1970 Massachusetts Institute of Technology study on
“Man’s Impact on the Global Environment,” suggested that greenhouse warming might bring “widespread droughts, changes of the ocean level, and so forth,”

1977 report on “Energy and Climate” from a panel of geophysicists
convened by the U.S. National Academy of Sciences stated there would be
“significant effects in the geographic extent and location of important commercial fisheries... marine ecosystems might be seriously disrupted.” Stresses on the polar ice caps might lead to a surge of ice into the sea, bringing a “rise in sea level of about 4 meters within 300 years.”

1983 study by the U.S. Environmental Protection Agency, studied sea-level rise. The experts concluded that by the end of the 21st century they “could confidently expect major coastal impacts, including shoreline retreat... flooding, saltwater intrusion, and various economic effects.”

Such concerns accelerated during the 80s, resulting in the formation of the IPCC. Their conclusions were difficult to reach and based on a vast array of data.

A conclusion that the observed warming is the result of human induced modification of the atmosphere is a rational one, based on the work of generations of scientists. That does not logically indicate that it is the correct conclusion, since not all evidence is available at all times, but it is a rational conclusion given the available evidence. That is how science works. Any accusation of deliberate, wide-spread conspiracy to deceive is irrational and either the result of historical ignorance or deceit.

Myth busting: Deniers and the phrase 'Climate Change'.

"Lefties have had to change the name from Global Warming, to Climate Change since it hasn't warmed since 1998. Why would they do that if they weren't up to no good?". Such claims we hear the deniers cry. As with the fact that warming has not actually stopped (but rather slowed) this statement is simply untrue. Leaving aside the obvious fact that the very organization that the ignorant constantly criticize is called the IPCC (CC=Climate CHANGE!) and was founded in 1988 (That's ten years before the supposed halt to warming), there are many other references to the actual phrase, or near enough, "Climate Change" that long predate the term global warming. When Climate Change is used in the 1950's, it is usually in terms of warming.

There simply has been no great change in the interchangeable usage of both the terms "Global Warming" and "Climate Change". Deniers who use this argument are one of: stupid, ignorant or liars.

These are the references I found in an hour with my friend Google:

 1916 Hartford Courant "FOSSIL ROCKS IN CANADA STUDIED: Remains of Earliest Animal Life Found SCIENTISTS SPEND MONTHS IN NORTH Measurement of Ice Flow Shows Climate Change."

1937 Miami News 1937 http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=13&ved=0CDQQqQIwAjgK&url=http%3A%2F%2Fnews.google.com%2Fnewspapers%3Fid%3DiMYuAAAAIBAJ%26sjid%3DVNQFAAAAIBAJ%26pg%3D6066%2C4768002%26dq%3Dclimate-change%26hl%3Den&ei=WY9hUpL2LePkyQG-w4GwCQ&usg=AFQjCNEWPyutlE0-LwiE8H_UiaH2n8thDw&sig2=PcSVRsaKACCgp3dObLlwGQ&bvm=bv.54176721,d.aWc&cad=rja

1939 Christian Science Monitor "World Climate Getting Warmer, and it's not the humidity. Although not a part of the climate change evidence, the world s coldest and hottest figures may be involved in the change." http://pqasb.pqarchiver.com/csmonitor_historic/doc/515570988.html?FMT=ABS&FMTS=ABS:AI&type=historic&date=Nov%207,%201939&author=&pub=Christian%20Science%20Monitor&edition=&startpage=&desc=World%20Climate%20Getting%20Warmer%20--And%20It%27s%20Not%20the%20Humidity

1952 Los Angeles times (Archive) "Weather Expert Finds Little Climate Change"

1953 Advert in the Spokesman Review http://news.google.com/newspapers?id=slsVAAAAIBAJ&sjid=LeYDAAAAIBAJ&pg=1951,3695705&dq=climate-change

Dec 2, 1955 The Hartford Courant "Climate Change Seen As Hurricane Cause"

1956 "The Carbon Dioxide Theory of Climatic Change" GILBERT N. PLASS (The Johns Hopkins University)

1956 New York Times "Pines 4,000 Years Old Found in California; Oldest Things Alive, Experts Say After Count of Rings 4,000-YEAR TREES GROWING IN WEST Response To Climate Change Dry and wet Alternation"

1958 Education documentary "Unchained Goddess" refers to climate change.

1958 New York times "Science In Review: Antarctica, preserved for research" refers to the phrase "climate Change" http://select.nytimes.com/gst/abstract.html?res=F1061FFF355F13728EDDA80994DD405B8889F1D3

1961 Geography "LAMB, HH. "Atmospheric Circulation, Climate and Climatic Variations." 46.3 (1961): 208-222.

1962 New York Times "Science Notes: Powerful Scope; ION Microscope - Climate Study.  In an effort to ferret Out clues to the nature and causes of climate change, " http://select.nytimes.com/gst/abstract.html?res=F50817FD3B551A7B93C5A8178DD85F468685F9

1971 Geological Society of America Bulletin 82.10 (1971): 2741-2754. Kent, Dennis, N. D OPDYKE, and Maurice Ewing. "Climate change in the North Pacific using ice-rafted detritus as a climatic indicator."

1972 Palm Beach Post "Greenland Ice Study" contains the phrase Climate Change http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=22&ved=0CC0QqQIwATgU&url=http%3A%2F%2Fnews.google.com%2Fnewspapers%3Fid%3DiaM1AAAAIBAJ%26sjid%3DILcFAAAAIBAJ%26pg%3D912%2C3895668%26dq%3Dclimate-change%26hl%3Den&ei=2Y9hUu_JAoGGyAHUt4GQAw&usg=AFQjCNFYzFmgNI5yS2ObQyWDsb0ZBDTAjA&sig2=B989zZbFHET3YJ7Q8aQLJg&bvm=bv.54176721,d.aWc&cad=rja

1975 Science article by geochemist Wallace Broecker of Columbia University's Lamont-Doherty Geological Observatory: "Climatic Change: Are We on the Brink of a Pronounced Global Warming?"

1976 Gadsden times "climate Change worries Soviets" http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=48&ved=0CEQQqQIwBzgo&url=http%3A%2F%2Fnews.google.com%2Fnewspapers%3Fid%3DcJdGAAAAIBAJ%26sjid%3DoP0MAAAAIBAJ%26pg%3D2855%2C1701489%26dq%3Dclimate-change%26hl%3Den&ei=C5JhUuCLI87lygHgm4GQAw&usg=AFQjCNH_1mYAcWZ8BMcSeiRI_ni9sYFlOA&sig2=oqwsd19vRTkGnXLPqdXO7A&bvm=bv.54176721,bs.1,d.aWc&cad=rja

1977 The Journal "Climatic Change" established.

1977 Deseret News http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=3&ved=0CDgQqQIwAg&url=http%3A%2F%2Fnews.google.com%2Fnewspapers%3Fid%3DSMdSAAAAIBAJ%26sjid%3DLX4DAAAAIBAJ%26pg%3D4384%2C5842345%26dq%3Dclimate-change%26hl%3Den&ei=hI5hUsySGaWzyAH95oGoAQ&usg=AFQjCNEubvXthxbkNVgu4N2_1j2vnaaSbw&sig2=VKWLut_NnqTP0VToFNiqBw&bvm=bv.54176721,d.aWc&cad=rja

1977 Deseret News "Great Lakes to Shrink Says botanist" http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=70&ved=0CEcQqQIwCTg8&url=http%3A%2F%2Fnews.google.com%2Fnewspapers%3Fid%3DlWVTAAAAIBAJ%26sjid%3DnYUDAAAAIBAJ%26pg%3D7097%2C5753233%26dq%3Dclimate-change%26hl%3Den&ei=jJJhUvekCaWGyAGS8IGYDA&usg=AFQjCNE9Q5yGM_GVKGC9s9NI0NIIcfE_5A&sig2=ICW5mtfyBbLp2VSUFfOoFQ&bvm=bv.54176721,bs.1,d.aWc&cad=rja

1978 "Scientists: Earth may be a desert by the year 2025" uses the phrase "climate change" https://www.google.com/url?url=http://news.google.com/newspapers%3Fid%3D2DpVAAAAIBAJ%26sjid%3Dyz0NAAAAIBAJ%26pg%3D6602,6834609%26dq%3Dclimate-change%26hl%3Den&rct=j&sa=X&ei=Z5NhUs_7L-jhyQHTtYCoCw&ved=0CD4Q-AsoADAGOEY&q=climate-change&usg=AFQjCNFynH6Vu2CtazKmQGsHSB2nekoErw&cad=rja

1979 Gadsden Times "Scientists Warn of Drastic Climate Change". http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=21&ved=0CCsQqQIwADgU&url=http%3A%2F%2Fnews.google.com%2Fnewspapers%3Fid%3Dm6QfAAAAIBAJ%26sjid%3DLtYEAAAAIBAJ%26pg%3D2526%2C1052831%26dq%3Dclimate-change%26hl%3Den&ei=2Y9hUu_JAoGGyAHUt4GQAw&usg=AFQjCNF8Njd186ABF1tws-ZiFgJPvafaYw&sig2=XbFQwT3F5t6vZ62oW_tPsg&bvm=bv.54176721,d.aWc&cad=rja

1979 New York Times "worldwide Errort is proposed to Study climtae and its impact" Contains the phrase "climate Change" http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=89&cad=rja&ved=0CE8QqQIwCDhQ&url=http%3A%2F%2Fselect.nytimes.com%2Fgst%2Fabstract.html%3Fres%3DF20D10FC3A5D12728DDDAA0994DA405B898BF1D3&ei=KpRhUvnpAaGwygGbj4DQCg&usg=AFQjCNGJQxG8FmAL351JtlaDxgeepYIyLA&sig2=3o0pGxelxXUobo-ht5j5bA

1980 Bangor Daily News http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=4&ved=0CDwQqQIwAw&url=http%3A%2F%2Fnews.google.com%2Fnewspapers%3Fid%3DAXg-AAAAIBAJ%26sjid%3DtVkMAAAAIBAJ%26pg%3D1088%2C1955014%26dq%3Dclimate-change%26hl%3Den&ei=hI5hUsySGaWzyAH95oGoAQ&usg=AFQjCNFgs3_HjedDtWgX23a8jl1emHYo_Q&sig2=tAf_6qgprkykGrjdiNgTdg&bvm=bv.54176721,d.aWc&cad=rja

1980 Journal of Atmospheric Sciences " On the Distribution of Climate Change Resulting from an Increase in CO2 Content of the Atmosphere."

1980 Science "Detecting Climate Change due to Increasing Carbon Dioxide"

1981 "Climate change and society: consequences of increasing atmospheric carbon dioxide" Barnes & Noble.

1984 Technical Report: "Response of unmanaged forests to CO2-induced climate change: available information, initial tests and data requirements" Solomon, Allen M., et al. Response of unmanaged forests to CO2-induced climate change: Available information, initial tests and data requirements. No. N-85-21817; TR-009. Oak Ridge National Lab., TN (USA), 1984.

1985 Journal of Geophysical Research "Trace gas trends and their potential role in climate change"

1987 Journal 'Climate' "Testing for Climate Change: An Application of the Two-Phase Regression Model"

1988 23 June  U.S. Senate, Committee on Energy and Natural Resources, "Greenhouse Effect and Global Climate Change" 100th Cong., 1st sess.,

1988 - Intergovernmental Panel on Climate Change (IPCC)

1988 - Boston Globe "WORLD FOOD SUPPLY IN PERIL, GROUP WARNS" contains "climate change" http://pqasb.pqarchiver.com/boston/doc/294498109.html?FMT=ABS&FMTS=ABS:FT&type=current&date=Oct%202,%201988&author=Dianne%20Dumanoski,%20Globe%20Staff&pub=Boston%20Globe%20%28pre-1997%20Fulltext%29&edition=&startpage=&desc=WORLD%20FOOD%20SUPPLY%20IN%20PERIL,%20GROUP%20WARNS

1988 Nature "Response of Northern forests to CO2 induced climate change. Vol 334
 
1995 - Influence of plants on climate probably more dramatic than previously thought" Mentions the phrase. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=newssearch&cd=100&ved=0CFgQqQIwCTha&url=http%3A%2F%2Fnews.google.com%2Fnewspapers%3Fid%3DqxIxAAAAIBAJ%26sjid%3DEOAFAAAAIBAJ%26pg%3D4910%2C3207991%26dq%3Dclimate-change%26hl%3Den&ei=EZlhUorXGuqmyQHwyYHYCA&usg=AFQjCNFDvv9wmyiWBEwWH5SuEOz1L8JpEA&sig2=1JpDFJRklm6KVFwDGhCEjQ&bvm=bv.54934254,d.aWc&cad=rja

1997 Time Magazine "Climate Change Summit - turning down the heat" http://content.time.com/time/magazine/article/0,9171,987564,00.html

On homosexuality

On homosexuality.

Is being gay a choice?

Is it unnatural?

Is it a sin?

Why are such questions important? Many members of our society are caused emotional pain to the point of suicide, physical damage to the point of death and denied the basic rights accorded to the heterosexual members of society, simply because they are sexually attracted to people who are the same sex as they are.  This is, to me, a question of human rights. No person, unless they are a threat to themselves or others, should be discriminated against, simply because they are who they are.  Every member of society should be treated equally before the law.  The last question on the list is important in a society like America which, contrary to the Constitution, bases law upon the Christian religion.

I shall argue that from both a purely theoretical and an empirical, scientific view point, being gay is not a choice.  That therefore leads on, for the Christian, to consideration of homosexuality being a sin.

Is being gay a choice?

Who would be willing to consciously be that which many in society, including family and friends, abhor?  Who would willingly expose themselves to ridicule, physical injury, the denial of basic rights and potential limitations of opportunity?  But, it may be argued, many young people rebel and follow paths that lead to rejection by the majority of their community.  People may adhere to other religions, or no religion for example.  However, that does not seem reasonable to me when it relates to sexuality.  I don't know about anyone else but I do not choose to start the day as a heterosexual.  I simply am, and always have been, attracted to women. I may be jealous of a better male physique or looks but there is no attraction and I would imagine that is the case for most other men.  To me, it is simply impossible for someone to choose to be gay.  They may choose to experiment, I suppose, but the basis of their sexuality is innate and beyond their control.

So what does the science say?  There is a great deal of evidence that sexual preference is not a conscious choice but a biological one.  That evidence also more strongly supports the idea that it is a physical rather than a social choice.  So, let's look at that evidence.

The incidence of homosexuality is comparable at about 10% in all cultures across the world.  If it was choice based then we would not expect this to be the case.

One of the biggest predictors of whether or not a boy will be gay is birth order with regard to other boys. (e.g. Separate studies by R Blanchard, Anthony F. Bogaert, EM Miller, JM Cantor, SJ Robinson and many others).  Many studies show that the likelihood of a boy being gay is directly influenced by the prior number of boys his mother has carried.  At face value, this still leaves the possibility that there is a social influence: the simple presence of older brothers influences the sexual preference choice of a boy.  However, the study by Anthony Bogaert deliberately addressed this issue.  That study, consisting of 905 men, found the birth order effect even when a child whose mother had had three or more previous male babies, was raised by another family.  This was true whether or not there were older non related brothers in that adopted family.  This strongly indicates that there is a major genetic factor involved.  However, this only applies to right handed gay men!  For left handed men, birth order was the opposite.  The majority of left handed gay men were more likely to be first born sons with older sisters.  So, it's complicated.  But whatever the case, it isn't a choice as these effects are purely biological and appear whether or not an individual is raised in the family that shares their genes, whether the adopted family has a similar make up as the birth mother's family or not.  So, if the family raising a child seems to be largely irrelevant with regard to that child's likelihood of being gay, what is it that can affect a child, no matter where they are raised? Answer: Their genes.

Some genetics

A common complaint from people who believe that homosexuality is unnatural and not genetically based is that if one half of a set of identical twins is homosexual then its partner must also be, because they have identical genes.  However, this ignores one very important fact: although we inherit our genes from our parents, not all the genes we receive are active in all off-spring, even if they are genetically identical.  For example, consider the human X chromosome.  We men only have one and we survive perfectly well,  In fact all humans, male and female, can only have one X chromosome and develop normally.  Men have only one X chromosome in each cell but girls two.  To avoid having too many products of the genes on those two X chromosomes, a girl's cells largely (but not totally) deactivate one of their X chromosomes at RANDOM!  No one knows what all the genes on the X chromosome do.  A girl gets one X from each of her parents but very early in her development, each of her constituent cells 'decides' at random that one will be silenced.  All the descendants of those cells within the developing girl inherit that decision.  It can be seen then that from their earliest beginnings 'identical' girl twins are not genetically identical at all.  While this obviously does not apply to boys with their single X chromosome, it illustrates the point.  More telling is the finding that the gene expression responsible for the development of disorders such as Arthritis is also different within identical twins.

Even though all our cells contain the same genetic code (except for red blood cells and gametes) they experience different life histories.  If they did not then we would remain single celled, undifferentiated organisms. In other words we would not have different cell types such as blood, nerve, muscle etc, if the genetic code was the whole story.  So, something else happens to the genes in our cells. They are expressed (have an effect) or they are silenced (they have no effect).  This is achieved by a process called methylation.  Technically, a methyl group is attached to a cytosine or adenine base in a DNA strand.  In other words a blocking chemical is added to one, or more, of the letters that make up part of the genetic code.  This prevents the expression of the gene that the code spells out.  It can be seen then that contrary to what many believe, the simple shared possession of a genetic code (genotype), does not mean that twins will be in all ways identical (have a shared phenotype).  Such influences are called epigenetic factors.    

That there is a genetic influence is borne out by twin studies. Twins are exposed to a similar family and environment, whether they share an identical code or not.  However, studies such as that carried out by J. Michael Bailey, an assistant professor of psychology at Northwestern University in Evanston, 1991, found that identical twins were more likely than other brother possibilities to be homosexual: 52 percent of identical twin brothers of gay men also were gay, compared with 22 percent of fraternal twins, compared with 11 percent of genetically unrelated brothers (adoptive).  This strongly suggests that in many cases, there are sequences of genes that do lead to a greater likelihood of homosexuality.  These sequences are then acted upon by epigenetic factors and birth order effect.

What might be the mechanism of the birth order effect?  There are two main possibilities:

1. Training of the mother's immune system.

2. Age of mother during gestation.

The first proposal considers that the mother's immune system may attack male baby's because they are seen as more alien than her own female cells.  With each male pregnancy this effect is said to increase.  One problem with this is that no immune factor has been identified that attacks only a woman's male children.

The second proposal is that the age of a mother quite naturally increases with each pregnancy.  It is a commonly known fact that the age of a mother has a direct effect on many genetically controlled aspects of her baby.  The incidence of genetic changes classified as abnormalities has been shown conclusively to increase with maternal age.  Older mothers are more likely to have babies who have Down's syndrome or Autism, for example.  Homosexuality is considered by this proposal to therefore be a genetic fault, the likelihood of which increases with age in the same way as other genetic conditions.

It is interesting to consider that the birth order effect (which is real and applies even to children reared apart) only affects right handed boys.  Do the conditions in the prebirth environment affect both sexuality and hand predominance?   Studies (McCormick, Whitlston, Kingston - 1990; A large meta study analysis by Martin L. Lalumiere, Ray Blanchard, and Kenneth J. Zucker Centre for Addiction and Mental Health and University of Toronto 2000, etc) have shown a direct link between left handedness and homosexuality.  Homosexual men are a third more likely to be left handed than the average man in the street.  Lesbians were nearly twice as likely to be left handed as the average woman.  There is a strong inheritance of left-handedness and in 2007 A massive study co-ordinated by Oxford university identified a gene linked to left handedness LRRTM1.  This gene is involved in brain organization and, if inherited from the father leads to an increased chance of left-handedness.  However, it also increases the chances of schizophrenia - also when inherited from the father.

From these studies it can be seen that brain organization (handedness), genetic code and prebirth environment all play a part in the development of sexuality.  A complex interaction between genes, maternal age/immune system and epigenetics all play a part in the likelihood of a child being born gay.

There is simply no evidence that homosexuality is a choice.  Michael Bailey is a professor of psychology at Northwestern University, working with genetically male infants born with malformed or ambiguous genitals. As he says,  in many such cases, surgeons construct a vagina, and instruct parents to raise the child as a girl, with no knowledge of his medical history. As adults, those prenatally male/postnatally female people were virtually all attracted to women. "If you can't make a male attracted to other males by cutting off his penis, castrating him and rearing him as a girl, then how likely is any social explanation of male homosexuality?"

"Gays don't have children so why doesn't a genetic preference for homosexuality die out? It goes against Darwinian evolution!"

This is another common complaint of those who believe that homosexuality is a conscious, unnatural choice.  However, they are wrong.  For one thing, even before the days of assisted reproduction, gays had children.  Gay women were raped and impregnated for example (it is disgusting to learn that lesbians have been raped to try to convert them to 'normal'!), and gays of both genders conformed to expectations, married and had children - Oscar Wilde was definitely gay but fathered two children.

But leaving aside societal pressure and force, there is nothing about Darwinian evolution that says that genes for homosexuality can not survive in a population.  The gene for sickle cell anaemia is recessive.  Each gene has an allele, that is at each point in our double helix of DNA, we have a version of a gene from each parent. If a person has a single sickle allele from either parent then they are a carrier.  If they receive a sickle cell allele from BOTH parents then they develop the potentially fatal sickle cell anaemia in which red blood cells are deformed and malfunction due to their sickle shape.  If sickle cell anaemia kills those who have it (without medical intervention) why does the Sickle Cell gene continue to exist?  Answer: because those people who inherit just one sickle allele, from one parent only, are afforded protection against malaria!  We therefore see that a genetic variety that also prevents its bearers from breeding (by killing them!) continues in a population just as homosexuality - which theoretically results in fewer offspring - does.

How would a homosexuality gene continue in a population?  There are two possible reasons:

1. Directly: As in the case of  sickle cell anaemia, a genetic sequence might improve the breeding chances of a none homosexual carrier.

2. Indirectly. Human beings are social creatures and have been for all of our known history.  As our brains have increased in size, so the nutritional demands of the newborn have increased.  It takes a lot of resources to raise human children to maturity and they are dependent upon those around them far longer than other species.  Those women who belong to a family group that includes homosexuals programmed to be so by genetics or epigenetic factors will have siblings who are less likely to breed.  They will therefore have more adults in the group available to provide resources for their nieces and nephews and not provide competing off-spring of their own.

It seems that both of these possibilities are true.  According to studies such as that carried out by  A. Camperio-Ciani, F. Corna and C. Capiluppi Proceedings of the Royal Society 2004. There is a strong connection between the maternal line of an individual and their homosexuality.  Homosexuals are far more likely to have homosexual relatives in their mother's family than their father's. In the reported study of a thousand individuals the rate of homosexuality in the maternal line was twice that in the paternal line.  But what has that to do with a gene providing a direct advantage to breeding success?  While the mechanism was not known, statistically the female relatives (on the female pedigree line) of homosexuals were found to produce more children.  Males did not.  There was no difference in fecundity for female relatives on the paternal side so this indicates that it is unlikely to be a simple case of birth order effect - i.e. that the female relatives of homosexuals simply have more children and are therefore consequently more likely to have a homosexual child.

Another indication that there is something intrinsically different about the genes, epigenetic factors or the prebirth environment within the mother in these families is the loss of uncles.  Again, this only affects the maternal side.  In a study of 500 hundred individuals by Richard Greene and EB Keverne, published in 2000 in the Journal of Theoretical Biology, a significant reduction in the number of male relatives was noted in the maternal line of homosexuals and transsexuals.

The same group led by Camperio-Ciani, who published the 2004 study noted above, published further research in 2012.  This showed a number of possible reasons for the increased fecundity of the mothers of homosexuals.  The mothers appeared to be more attractive to men - they were more feminine and outgoing - and they also had fewer gynaecological and obstetric problems.  However, on the negative side, they were significantly more likely to experience a divorce. (Perhaps precisely because they are more attractive to men and more out-going!?)

What conclusions can be drawn?  At least with regard to a large percentage of gay men, it appears that a genetic situation exists which leads to feminization of the unborn child.  If that goes too far then a male child is lost (hence lower numbers of male relatives).  Birth order effects might lead us to conclude that rather than being an effect innate to the child, it is something which affects the prebirth environment within the mother, most likely her immune system.  Each exposure to a male child seems to lead an increased immune response to a male baby.  Bear in mind that this explanation is largely applicable to right handed boys and not left handers.  But it does show that for a significant proportion of gay males all the evidence supports a genetic influence.  That this influence is X Chromosome linked is indicated by the effects upon the female line.  A boy always inherits his X chromosome from his mother who does not have a Y chromosome to pass on, of course, and hence a boy MUST receive his Y chromosome from the father.  X and Y make a boy.  The, as yet unidentified X located genes, also have the effect of increasing the breeding success of mothers by making them more attractive (feminine) to men.

There is, as yet, no similar evidence based explanation for lesbianism. However, there is evidence that there is a strong genetic factor (at least 25 - 30% of the influence is genetic).  A study in the UK, published 2011, Andrea Burri and Qazi Rahman Queen Mary University, London, followed a large sample (4000 individuals and therefore likely to be significant) Identical female twins reared in the same environment were more likely to be lesbian than non-identical female twins were.  Additionally, it is interesting to note that lesbians are twice as likely to be left handed as the average woman. Hand preference is not under conscious control it is innate and probably genetic.  This is supported by the fact that hand preference can be predicted by the study of a person's hair.  Right handers are far more likely to have hair that swirls clockwise at the crown. 95% of Right handers have clockwise hair swirls where left handers and the ambidextrous show no preference. ( Amar Klar of the National Cancer Institute in Frederick, Maryland).  It is also known that left handers are more likely than right handers to experience negative medical conditions.  They are twice as likely to suffer Crones Disease (2001, 17,000 sample size, University college, London).  Also left handed women are twice as likely to suffer breast cancer (British Medical Journal, 2005, University Medical Center Utrecht 12,000 sample size).

So, homosexuality seems to have a very strong genetic component, either within the mother - in the case of male, right-handed homosexuals, or within the child with regard to lesbians (identical twins and fraternal twins  all share the same prebirth environment, including the mother's immune system.  The influences are complex and more than one applies in different situations but one thing is clear: Homosexuality is most definitely not a choice.

Is homosexuality a genetic disorder then?   No.  Many genotypes provide positive and negative impacts.  Take height as an example.  The incidence of cancer increases 16% for every four inches of extra height (Cancer Research UK 2011, 1 million sample size).   Men over 6 ft tall are twice as likely to develop life threatening blood clots in their legs ( Aaron Sweeney, a consultant vascular surgeon at Lewisham Hospital.)  However, studies (Pierce, C.A. 1996; Cunningham, M.R. 1990; Pawlowski B, Dunbar RI, Lipowicz A 2000.) have shown that women find tall men more attractive and that they have more children.  This is theorized to be due to mate selection based on apparent fitness. A man has to have resources, and the skill to obtain them, in order to actually reach his genetic height potential.  That is attractive to potential mates.  We can see therefore both homosexuality and increased height can improve breeding success at the cost of some health problems.  In the case outlined most clearly above, homosexuality can lead to increase loss of male babies but the possession of a homosexual influence leads to an actual increase in the direct fecundity of 'carrier' mothers plus a theoretical benefit in terms of non reproducing uncles providing resources in less organized societies.  Additionally some studies, but not all, have shown an increase in intelligence and creativity among homosexuals (SATOSHI KANAZAWA, Journal of Biosocial Science 2012).  Anecdotally, this seems reasonable to me.  When HIV/AIDS first occurred in the 1980's it was the entertainment industry that was initially devastated. 

If we are to argue that being gay is a genetic disorder that causes ill health then we would also have to argue that tall people are suffering from a genetic disorder.  Being gay is a result of biological processes that have positive and negative consequences, just as many other phenotypes do.  It is, therefore, perfectly natural and certainly not the result of choice.

Since it is the result of developmental processes, homosexuality is also not a condition subject to treatment any more than being tall is.  The brains of homosexuals are simply wired differently to those of heterosexuals.

Conclusion

Homosexuals are just one version of humanity and, as such deserve all the human rights that the majority of society enjoy.

For we Christians:

Is homosexuality a sin?

Is it reasonable to accept that a loving, reasoning God would allow individuals to be physically created homosexual, following the biological processes that God created, and then condemn them for it?  I do not believe so.  Would God create a fish and then condemn it for being a fish?  Sin is the deliberate disobedience to the will of God.

Suppose, for the sake of argument, that an unreasonable God would allow the creation of gay people but then tell them not to actually have gay sex.  In other words, being gay is not itself a sin, the sin is in gay sex.  That seems illogical to me but, Ok, what are the consequences.  Those who believe this way condemn themselves.  If we are to take the Bible literally, Jesus said that adultery is not just the physical act but the very thought of viewing a woman with lust.  Most of us can not control our thoughts anywhere near to that extent and are attracted to other people.  It is what we do about that attraction that is important.  I think the statement attributed to Jesus is unreasonable and largely impossible.  It is responsible for so much angst through out the ages.  So the same applies to gays.  A gay person cannot help being attracted to people of the same physical gender that they are.  If the statement attributed to Jesus were correct then a gay person would be created by the processes instituted by God and immediately condemned not just for gay acts but for the gay thoughts that their very nature can not help but create.  And that is completely unreasonable.  No sane, loving God could allow that situation.

  

A Christian Perspective on the Death Penalty

Many Christians state that they follow Christ but also support the death penalty.  I believe the two to be incompatible because of what Jesus taught and how he behaved.  We can think of many reasons why we should do the things that we believe are the correct course of action.  But if we call ourselves Christian, the followers of Jesus Christ, then our actions and beliefs must be based upon what our Lord said and did.  There are other reasons a Christian would best be against the death penalty. Reasons not specifically spoken of by Jesus but which can be inferred. I shall discuss why they make me opposed to the death penalty.  I will look at some scripture and argue from that before reaching a conclusion.  Only from reading the words of Christ can we decide what the truly Christian path is.  In areas where the evidence is equivocal, it is surely best to err on the side of caution and forgiveness, to take Jesus teaching as a whole.

The death penalty existed in the Jewish society that Jesus lived in.  Mosaic law prescribed stoning to death as the punishment for a variety of crimes such as adultery, murder and even disobedience of a child to a parent. Many say that Jesus stated he had not come to change a letter of the law and that Biblical accounts of God instructing the killing of criminals means that we are free to do so today.  But he proceeded to do exactly that and not only with regard to judgement and punishment of sinners. The Old Testament lists the commandments of God with regard to what may and may not be eaten.  But Jesus totally contradicted that when he said that it doesn't matter what you eat, what goes into the mouth, but what comes out.  Similarly when confronted by those who said the Law demanded the adulteress be stoned, what did Jesus say?

" He who is without sin among you, let him throw a stone at her first." John 8:7

Jesus stated that the greatest commandment was love:

Matthew 22:37  “‘Love the Lord your God with all your heart and with all your soul and with all your mind.
This is the first and greatest commandment.  And the second is like it: ‘Love your neighbor as yourself. All the Law and the Prophets hang on these two commandments.”

But surely, the response might be, Jesus wasn't talking about criminals? Jesus himself stated that he was talking of EVERYONE, even our enemies who might try to kill us.

"Love your enemies, do good to those who hate you, bless those who curse you, pray for those who mistreat you. He causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous. If you love those who love you, what reward will you get? Are not even the tax collectors doing that? And if you greet only your own people, what are you doing more than others? Do not even pagans do that? Be perfect, therefore, as your heavenly Father is perfect."

It is natural for humans to want to impose justice, fairness.  If they are wronged they wish to wrong the perpetrator.  But what does Jesus say?

"You have heard that it was said, 'An eye for an eye and a tooth for a tooth.' But I tell you... whoever slaps you on your right cheek, turn the other to him also." Mat. 5:38-39

"But if you do not forgive men their trespasses, neither will your Father forgive your trespasses." Mat. 6:15

:Bless those who persecute you; bless and do not curse... Repay no one evil for evil... do not avenge yourselves, but rather give place to wrath; for it is written, "Vengeance is Mine, I Will repay," says the Lord." Rom. 12:14, 17, 19

Repay no one evil for evil and let God settle questions.

Jesus says that we should not judge at all.  Many argue that He meant you could judge but only if you applied the methods of judgement to everyone, including yourself.  However, that ignores the second half of the statement.  Context is everything.  Jesus was saying that you should not judge AT ALL.  He referred to pointing out the faults with others when you yourself have faults.  Only those without sin may judge.


Matthew 7 “Do not judge, or you too will be judged. For in the same way you judge others, you will be judged, and with the measure you use, it will be measured to you.

 “Why do you look at the speck of sawdust in your brother’s eye and pay no attention to the plank in your own eye? How can you say to your brother, ‘Let me take the speck out of your eye,’ when all the time there is a plank in your own eye? You hypocrite, first take the plank out of your own eye, and then you will see clearly to remove the speck from your brother’s eye.


Mercy.  God is ever merciful.  If we are instructed to be perfect, as God is perfect, even with those who can be considered evil then we too must be merciful.

Blessed are the merciful: for they shall obtain mercy. (Mat 5:7 KJV)

1 Peter 1:3 Blessed be the God and Father of our Lord Jesus Christ, which according to his abundant mercy has begotten us again to a lively hope by the resurrection of Jesus Christ from the dead,

It is too easy to see another human being in terms of one act that we believe deserves to be punished but they are more than that.  Illness, fear, pressure, circumstance all may cause an individual to commit terrible acts.  Not one of us can tell how we would behave in all circumstances.  A psychological study in the 1960's found that ordinary, everyday people were quite willing to administer what they believed were lethal electric shocks to victims given the right circumstances.  Interestingly, one man refused and later went on to win the Purple Heart.  The vast majority of people could be manipulated into performing actions of which they would have thought themselves incapable.  So not only are we directly instructed by Jesus that we are sinners and should not judge others - we have proof that we can be just as bad as some of the worst offenders, given the right circumstances.

God loves us so much that He sent his only son to save us.  We state every week, in church, that this is what we believe.  God loves ALL of us, the good, the bad (and of course the ugly!) according to the quotes of Jesus, above.  He tells us that he will judge us and that we should not judge each other.

Even after accepting that Jesus meant us to love the evil, some may say that murder is such a terrible crime that it is deserving of death.  Is there any sin that is unforgivable?  What did our Lord say?  In Matthew 12:31-32, Jesus says to the Pharisees:

"Therefore I say to you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men. Anyone who speaks a word against the Son of Man, it will be forgiven him; but whoever speaks against the Holy Spirit, it will not be forgiven him, either in this age or in the age to come"

Jesus didn't add "Oh, I forgot, and murder too."  If almost every sin - except speaking against the Holy Spirit - are forgivable, who then are we to kill another of God's children?

In fact by killing another human being, are we not being hypocritical?  If we state, every Sunday, that our sins have ALREADY been forgiven by the sacrifice of Christ are we not guilty of killing one that Christ has already forgiven?

If we kill someone we end their spiritual development.  The person can no longer learn about God, can not change.  God wishes for us to turn away from evil and to return to him.  The parable of the prodigal son tells us this. There is no return of the prodigal son if we have killed him.  In killing another we deny them the chance to repent.

The taking of human life was so against what they saw as the teachings of Christ that the early Christians refused to kill, even in self defense during the first centuries after Christs death.  This even extended to the armed forces.  Although there were Christians who became soldiers, many writers claimed that to be a soldier was not compatible with Christianity and that such people were not suitable for baptism. Hippolytus of Rome "A soldier of the civil authority must be taught not to kill men and to refuse to do so if he is commanded, and to refuse to take an oath. If he is unwilling to comply, he must be rejected for baptism. A military commander or civic magistrate must resign or be rejected. If a believer seeks to become a soldier, he must be rejected, for he has despised God." Arnobius of Sicca "For since we, a numerous band of men as we are, have learned from His teaching and His laws that evil ought not to be requited with evil, that it is better to suffer wrong than to inflict it, that we should rather shed our own blood than stain our hands and our conscience with that of another, an ungrateful world is now for a long period enjoying a benefit from Christ, inasmuch as by His means the rage of savage ferocity has been softened, and has begun to withhold hostile hands from the blood of a fellow-creature."

Our society can not function without the enforcement of Law. But we have to accept that the application of law may not be what Christ intended for us.  As I said at the start, we can think of many logical reasons for behaving as we do but if our words and actions do not follow those of Christ, then we are not Christian.

In order to prevent those who commit evil deeds from continuing to do so, we may accept that we should restrain them and prevent them from doing so.  But for the reasons stated above, we should not destroy another of God's children and deny them the chance of redemption.


Christian or otherwise, there are other reasons for being against the death penalty.  Those reasons concern human fallibility.  Fully one in seven criminals on Death Row in America during the 1990s, were proven by the new technology of DNA profiling, to be innocent...  Think about that.  How many entirely innocent people were killed by the state?

Aside from simply being wrong, another failing of many is racism. This is true of prosecutors, jurers and judges passing sentence.   Consider Georgia.  The 1998 Baldus Study found that the racial combinations of murderer and victim had a dramatic affect upon the sentence of death. Prosecutors sought the death penalty in 70% of the cases involving black defendants and white victims; 32% of the cases involving white defendants and white victims; 15% of the cases involving black defendants and black victims; and 19% of the cases involving white defendants and black victims.  When it came to actual sentencing black defendants charged with killing white victims were 4.3 times as likely to receive a death sentence as defendants charged
with killing blacks. Overall black defendants were 1.1 times as likely to receive a death sentence as other
defendants.  Again, think about that.  How many innocent black men were killed by the state, simply because they were black?

The mentally ill: It is only since 2002 that the Supreme Court has stated that it is illegal to execute the mentally disabled.  Prior to that date people who had no idea that their actions were wrong, who had no idea what was happening to them, were killed by the state.  Many states are still executing those who are severely mentally ill.

Effectiveness: What is the purpose of the death penalty? To punish and prevent further murders? Britain, as most of Europe, does not have the death penalty but has a lower murder rate than the US. Hardly effective then is it?

From Christian, humanist and simple practical perspectives support for the death penalty is unsustainable and barbaric.

Global Warming. The arguments in favour.

Let's start with some basic information about the rock on which we live.

Our planet, our amazing Earth, is a ball of mostly molten (to at least some degree) rock, floating in the vastness of space.  We live on the solid crust, the lithospere, which is approximately 50 miles thick and comprises less than half a percent of the Earth's depth.  The core of our planet is 'solid' but still extremely hot.  It's solid state is not due to it being cool then, but is due to the enormous pressure preventing free movement of its constituent atoms.

The atmosphere that surrounds us is about 600 miles thick in total, but 90% of the air that makes up that atmosphere is contained in a layer just 7 miles thick.

The heat in the Earth - some 6,700 degrees Celsius at the core - has a minimal warming effect at the surface because rock is a poor conductor of heat.   On average the warming of the crust by heat flow from within the Earth is about 0.087 Watts of energy per square metre.  The source of that energy is primarily radioactive decay (80%).  The remaining energy comes from that left over from the collisions that created the Earth.

How does that heat from within the Earth compare with that received from the sun? It is infinitesimally small in comparison.  On average the amount of energy from our closest star is 164 Watts per square metre of the Earth's surface.  However, that varies because the output from the sun is not constant.  The sun goes through regular cycles, waxing and waning in power.  These cycles occur at regular 11 year intervals and can be observed by measuring the solar wind and numbers of sun spots. As the cycle reaches what is called solar minimum, and the number of sunspots decrease, so the amount of energy hitting the Earth falls.  How do we know this?  Well, sunspots have been recorded for thousands of years (Earliest known mention was 364 BC by the Chinese astronomer Gan De) and their absence is correlated with lower temperatures.  Correlation does not show cause and effect but modern astronomy has directly measured the energy of the sun as the number of sunspots wax and wane.  Since the laws of physics are not known to change, it is reasonable to conclude that the amount of energy reaching the Earth was low during low sunspot periods of the past.  Take the period of roughly 1645 to 1715, known as the Maunder Minimum. During that period there were virtually no sunspots and the temperatures plummeted.  That the sun's output was low during such periods of cold is borne out, not only by sunspot numbers but also by the relative amounts of such substances as Carbon 14 and Beryllium-10. The amounts of these substances increase as the amount of solar radiation decreases since they are formed by cosmic ray interaction with our atmosphere.  Cosmic ray levels increase as the solar wind decreases.  This solar wind makes Earth habitable by screening us from these rays.

So, the primary source of heat energy on Earth is the Sun.  Further evidence of this comes from our direct experience (toward the poles) of reduced solar radiation per square meter of the Earth during each Winter of the year. As the inclination of the Earth toward this primary heat source changes, so does the temperature.  Nothing else steps in to warm the Earth in the absence of the sun.  But why do we experience the temperatures we do? Because of the atmosphere.

The moon lacks an atmosphere but is, to all intents and purposes, at the same distance from the sun as Earth.  It orbits our planet at an average distance of about 240,000 miles. A little under a quarter of a million miles, then.  Given that Earth is an average 93 million miles from the sun, the fact that the moon moves toward and from the sun by a quarter million is irrelevant.  So what is the temperature like on the moon, with no atmosphere?  The day time temperature of the moon is 107 degrees Celsius - more than hot enough to boil water. At night the temperature drops to -150 degrees Celsius.  If the Earth did not have an atmosphere then similar figures would apply to our planet.  They would not be exactly the same due to the different rotational periods.  Earth rotates more quickly than the moon and so there would be less time to reach extremes.  Less time for any point to be exposed to the sun or to have no sun exposure.  However, that only makes slight differences. With no atmosphere, the average temperature of the Earth would be -18 Celsius.

So how does the atmosphere regulate the average temperature of the Earth?  The atmosphere acts like a blanket.  Just as a blanket on a bed slows the heating of an individual in a warm room and slows the cooling of the same individual in a cool room, so the atmosphere does the same for the Earth.  It reflects some of the incoming radiation back into space (about a third) and also, once that radiation is converted to infra-red radiation on contact with the surface, delays that radiation going back out into space.  The secondary effect of the atmosphere is to allow the spread of heat around the planet.  Streams of air carry the heat from day to night sides of the planet and from Summer to Winter hemispheres.  In other words, the atmosphere softens the extremes of global temperatures.

Does the temperature of the Earth rise and rise indefinitely? No.  All the energy of the sun is either re-radiated back into space (in one form or another) or, to a very small extent, converted to more permanent forms such as organic compounds. Living things use the energy of the sun to build their structures and then those structures are converted to oil, coal and gas.  That energy is released when the fossil fuels are burnt and converted back into heat that is again radiated back into space.

How does the atmosphere hold onto heat?  The atmosphere largely allows light from the sun to enter freely.  What happens to it then depends upon what it hits once it has finished it's journey through that atmosphere.  The simple physics of matter mean that things we humans perceive as light in color reflect the suns light back out into space.  Progressively darker surfaces reflect progressively smaller amounts of the energy they receive back out.  A black object absorbs virtually all of the light hitting it.  That's why it appears black to our eyes.  There is no light radiation for us to detect.  The energy of that light is not lost - a physical impossibility - it is changed.  What it becomes is infra-red radiation, otherwise known as heat.  We humans can't see it but our technology, and other creatures can.  Warm things radiate their energy in the infra-red spectrum.  That energy is radiated into space too.  However, some substances capture that infra-red radiation as it heads back up from the surface of the Earth.  These are what we call the Greenhouse Gases because, although they use a different method, their effect is the same as the glass in a greenhouse - they delay the passage of heat.

Not all of the gases in the atmosphere have this effect of capturing heat and are therefore not Greenhouse gases.  Only those which consist of two or more different atoms fit the category.  So, Nitrogen (N2), Argon(AR) and Oxygen (O2) are not greenhouse gases, Carbon Dioxide (CO2), Water vapour (H2O) and Methane (CH4) are.  The bonds between those atoms absorb the infra-red radiation and re-emit it in all directions.  Some will continue its journey out into space but some is sent back toward the Earth's surface.  How does it do this? Heat is simply the vibration of atoms.  This is basic physics.  As a substance cools, it's molecules vibrate less until at absolute zero they are motionless.  Photons of infra-red radiation strike the atomic bonds of molecules in the atmosphere, converting light energy into kinetic energy.  The increased vibration of these molecules is experienced as heat.  As the molecule returns to its pre-collision state and slows, its kinetic energy is converted back into infra-red radiation.

The more of these gases there are in the atmosphere, the more heat energy is retained and the higher the temperature we experience is.  We know this is the case because, as we saw above, simple physics which was developed long before any controversy over whether or not we are affecting the climate, states that the Earth should be some 33 degrees Celsius cooler than it actually is.   We also know the physics, described above, which shows why the Earth is warmer than it should be.  Greenhouse gases temporarily trap heat within the atmosphere.  This is what allows us to live on planet Earth in the first place.  This physical process also explains the temperatures of other bodies in the solar system. Venus is far hotter than it's size and distance from the sun would predict.  At 462 degrees Celsius the surface temperature is hotter than that of Mercury at 420 degrees Celsius.  This despite the fact that Venus, at a distance from the Sun of 76 million miles, is twice that of Mercury at an average distance of 35 million miles.  What is distinctive about Venus? It's massive atmosphere is 96% Carbon Dioxide!

This gives rise to one of the questions that opponents of global warming have to explain.  If the principles of physics tell us what the average temperatures of Earth and Venus should be, why are they not at those temperatures? How do we explain the observed differences from expectation in the two planets - consider the difference between Venus and Mercury especially the inverse relationship between temperature and distance.  One oft used argument is that water vapour is a potent greenhouse gas and it is that which is raising the temperatures of the planets and not CO2.  However: what causes water vapour levels to rise? The temperature!  Water vapour IS increasing and will add to the Greenhouse effect on Earth.  But increased water vapour is a symptom of increased warming not the initial cause!  Venus has virtually no water anyway.  But I get ahead of myself here.  Back to basics.

Ok, so the Earth is warmer than the physics of black-body radiation would suggest and it appears that this is because of its atmosphere and the presence of greenhouse gases, particularly carbon related gases such as Carbon Dioxide and Methane (the levels of which are also rising alarmingly) Methane has 25 times the greenhouse effect as Carbon Dioxide but each molecule only lasts about 8 years in the atmosphere, compered to over a hundred years for CO2.

Given the effects of physics on basic physical objects and the fact that an atmosphere blankets such a body, increasing it's surface temperature, what else affects the temperature of the Earth?  Let's go back to the absorption of light again.  Technically the absorption of light energy is said to depend upon the albedo of an object.  Simply put - how light in colour it is, from the Latin for 'Whiteness'.  The whiter an object is, the more light it reflects unchanged back into space.  We can see then that the more snow there is on the surface of the planet, the cooler it is because it absorbs less of the energy of the sunlight which hits it.  As we know, the continents slowly drift across the face of the planet.  This is driven by the heat of the inner Earth forcing apart the continental plates at the mid-oceanic ridges and the further edge of the plate sinking into the subduction zones. As these plates move they wander closer and further from the poles.  Extensive land masses toward the poles give a surface on which snow can accumulate and therefore reflect sunlight, cooling the planet.  Without a land mass upon which to accumulate there would be no white surface.  The north polar cap of the Earth , while consisting mainly of floating ice, is anchored by the surrounding land and the sea is not very deep, not deep enough to be an ocean.  At an average 3,400 ft deep it is actually a sea, part of a flooded continent plate, rather than ocean (average 14,000 ft deep).  Antarctica consists of land, upon which ice and snow have accumulated, plus the surrounding ice anchored to it.  At other times in Earth's history the continents have come together at the equator and there have been no polar ice caps.  200 million years ago the land masses were much closer toward the equator.  Subsequently Antarctica has drifted south while Europe and the America's further north.  Not only do continents directly affect the temperature by providing a surface for reflective ice and snow to accumulate on, they do it indirectly too.  The presence or absence of a continental mass allows or blocks the flow of ocean currents which distribute heat around the planet.  This is important because although that distribution does not affect the total amount of heat within our atmosphere, it does affect where it reaches.  If an area is cut off from the heat transported by the ocean it cools.  As a result it is again more likely to allow the accumulation of ice and snow and thereby reduce the absorption of heat by increasing the albedo.

Volcanism affects the the temperature of the Earth's surface but not in the way that is often cited by global warming deniers.  Volcanoes do, indeed, release large amounts of CO2.  However, they also produce large amounts of particulates and sulphur.  The net effect of volcanoes is to LOWER the temperature in the short term and to have a relatively insignificant effect (compared to us) in the long term.  The amount of CO2 released by volcanoes each year is (maximum estimate 300 million tons) How much is released by our burning fossil fuels? 29 BILLION tons.

So, is the Earth actually warming?  All the evidence would suggest that the Earth warmed dramatically during the latter half of the 20th century and that while the rate of heating has decreased in the early part of this century, it has continued.  There are various lines of evidence.  The actual measurements of temperature show that the temperature continues to rise.  According to NASA, 2012 was the hottest year on record.  Far from warming having stopped in 1997 (as some would have us believe) the ten warmest years recorded have all occurred since 1998.  The September sea ice mass for the Arctic has reached its lowest point ever recorded in 2012, a trend continued for at least the last thirty years.  The global ice mass measurement is down 500 billion tons on 2002 levels.  A constant downward trend for at least the last decade.  The Greenland ice mass loss is particularly worrying.  In 2012 the mass loss was 1,000 billion tons, again a continuous downward trend for the last decade.  Sea level continues to rise.  In 1998 the average sea level was 5mm higher than that in 1993.  With a slight dip in 2011 the rise has been steady and average sea level is 65 mm higher than 1993. Each year the records for high temperature are broken, glaciers and ice sheets shrink.

A counter argument put forward by deniers is that ice is actually increasing in Antarctica so that in some way counters the idea of global warming.  It does not.  As the above figures show, global ice levels continue to fall. The fact that ice accumulates in Antarctica is exactly what would be expected in a warming world.  Global water vapour levels have increased. In any area in which the temperature remains low enough to accumulate ice rather than lose it, that increased water vapour will lead to increased accumulation. 

So, what is happening that might explain the changes we are observing?  Is the sun increasing its output, is the earth capturing more heat?  Let's see.

Prior to the industrial revolution ice cores show that the CO2 concentration of the atmosphere was around 270ppm.  Today it is far higher and the levels have consistently risen over time.  In 1959 the CO2 level was 315ppm.  Today it is 393 ppm.  Every year the level has increased.  Given our knowledge of the physics of CO2 as a Greenhouse gas, the question for deniers is: Why, in your world view, has the increased CO2 NOT warmed the planet?  Basic physics, unconnected with the funding of global warming research, tells us that CO2 is a greenhouse gas that warms the Earth.  But massively increasing its levels in the atmosphere is supposed to have done nothing?  Where is that extra CO2 coming from? The burning of fossil fuels.  We release 29 billion tons of CO2, that nature had locked away, out of the carbon cycle, every single year.

We saw earlier that the sun is the primary source of heat for the Earth's surface.  What has it been doing?  Can it explain the current warming? For much of geological time, yes, rises and falls of temperature tie in very well with solar activity.  But not recently. The sun has been very quiet.  In the last 35 years, solar output and Earth's temperature have been diverging.  While the trend was increasing solar output from the start of the twentieth century to about 1960, subsequently the sun's output has been in decline.  In 2009 the total solar output was the lowest recorded in over 100 years.  The sun, far from heating our planet, may actually lead to a reduction in the consequences of our increasing the CO2 levels of the atmosphere.  There is even talk in the astronomical community that the next solar cycle might not even occur.

How can we tell what the sun was doing thousands of years ago?  That takes us back to Carbon 14 and Beryllium-10.  These are stored in the carbon taken up by living things (giving us Carbon dating) in the case of Carbon 14 and locked in ice cores and sediments, in the case of Beryllium 10.  10B has a half life of one and a half million years before decaying into Boron 10.  This means that measuring the ratio of 10B to 10Be means we can see what the sun was doing millions of years into the past.  This is because the formation of 10Be is the result of cosmic rays causing a nuclear reaction between Nitrogen and Oxygen in the air. Cosmic ray levels depend upon the levels of the solar wind.  This means we can get a good idea of what the solar wind was like over long periods and hence the output of the sun.

There is one other piece of evidence that indicates that it is a change in the atmosphere that is causing warming rather than any other influence and that is night time temperatures. The difference between day and night time temperatures is falling.   Since there is no extra heat being put into Earth's climate system just at night, the logical conclusion is that the atmosphere is simply not releasing the heat accumulated during the day as swiftly as it once did.

In conclusion then, it is entirely reasonable to conclude, upon the basics of the laws of physics, that human increases in the levels of CO2 are causing the temperature to continue to rise.  The Earth has indeed had natural cycles of warming that have exceeded those seen today.  But those cycles do not just happen out of no where.  They are not unexplained.  There are reasons.  These reasons do not apply now.  While science can not tell us all the details, all the evidence points to increasing CO2 levels being the primary cause of recent and continued warming.  There is no alternative hypothesis which accounts for all the evidence.