cosmic ray fission forms beryllium and boron

dying low mass stars convert the their helium to carbon and nitrogen but also form much of the heavier elements from strontium to lead

colliding neutron stars form much of the heavy metals and rare earths including platinum, gold, uranium, and plutonium

now thought to have taken some 5 million years for it to form into a planet ¹⁾

it is thought that another earth-like planet but half of earth's size, Theia collided with earth as it was developing some 4.5 billion years ago and the heat of the impact creating magma oceans and ejected a lot of the mass of Theia and this ejected debris coalesced to form the moon which is thought to consist of 80% Theia and 20% earth, but with much less iron as this is heavy and was retained on earth, and much less low atomic weight elements such as hydrogen as the heat would have boiled these off.²⁾

iron and to a much lesser extent, nickel are the most abundant heavier atoms in the solar system and thus, along with sulfur as sulfides, formed the core of the “rocky planets” with the crust containing a variety of other atoms - in particular, oxygen bound to silicon as silicate minerals with very high melting points and low vapor pressure, which allowed oxygen to be retained on earth and contribute to 46% of the mass of the crust, while silicon contributes 28%. Oxygen constitutes 86% of the mass of the oceans in the form of water.

the solar heat drove most of the volatile compounds into space (such as elements lighter than oxygen including carbon and nitrogen, as well as sulfur, selenium, hydrogen telluride and the inert gases), although earth's gravity has maintained some gases trapped in the atmosphere.

there are 70 sextillion (7×10^22) stars in the observable universe, and of the 200-400 billion stars in the Milky Way, there are billions of stars in just our galaxy that are similar to the Sun

we now know that almost every, if not every, star has at least one planet

if we assume 25% of such planets are at a reasonable temperature for life, and if we take a pessimistic assumption that the probability of an intelligent civilisation having occurred on any such planet is 1 in 10 billion, then the maths suggests that around a trillion such civilisations have existed in the universe!³⁾

~4.51 billion years ago: massive impacts on earth formed the moon

fortunately, earth developed a strong geomagnetic field which is able to repel enough of the solar winds to allow an atmosphere to build up and not be stripped away as it occurred on Mars (Mars did have a geomagnetic field 3.7bya which allowed water to flow and an atmosphere but lost the protective field and then its atmosphere)⁴⁾

the Late Heavy Bombardment of meteors ends c3800 mya

deposition of ferric oxide in the Banded Iron Formations begins c 3,800 mya

oceans rich in ferrous sulphate and carbon dioxide

atmosphere rich in methane, carbon dioxide but poor in free oxygen

Great Oxygenation Event (GOE) 2400 mya with evolution of oxygen-producing cyanobacteria

2 billion yrs ago - mass extinction event of cyanobacteria perhaps due to lack of nutrients such as phosphorus

multi-celled organisms, soft-bodied invertebrates further oxygenate atmosphere

Eocene epoch - horse, rhinoceros, camel, rodent, monkey, modern birds, aquatic mammals

Leaders of the Dark Ages

Britain: Vikings invade Britain

Europe: Charlemagne's empire; Byzantine and Western Roman empires;

Middle East: Mohammed, Otto the Great; Arab empire;

America: Toltec civilisation

Leaders of the Middle Ages

Britain: Norman conquest of Britain - Erik the Red; Macbeth;

Europe: Holy Roman Empire - crusades, Inquisition

America: Vikings in Nth America

Asia: Jenghiz Khan rules Nth Asia

Europe: Hapsburg dynasty, Marco Polo, Dante; Ottoman empire

Britain:  Chaucer, 100yr war with France, War of the Roses,

Joan of Arc,

Middle East:

Incas' and Aztec empires in Americas

history shows us that rapid warming over a period of 70yrs caused ice berg break up in Canada which migrated east to France and these were then followed by decades of intense cold with soil deep frozen as far south as southern France.

the Gulf Stream is driven by the stream's fall to the bottom of the sea in the Baltic as it gets colder and more concentrated (thermohaline circulation) but this can be disrupted by excessive ice berg or glacier melting which dilutes the waters.

turning off the Gulf Stream means warm tropical waters from the Mexican Gulf will no longer moderate temperatures in the Norwegian Sea with resultant cold climate for northern Europe.

sea levels would rise by 1m in northern hemisphere and drop in the south.

2007 showed evidence of decreased salinity, increased ice berg and glacier break up while Arctic seas are open to shipping for longer periods each year due to less sea ice.

probability of this occurring: perhaps 2% in next decade and 50% in next century.

geo-thermal power

new higher efficiency solar cells based on quantum crystals

“clean” coal power stations

methane hydrate ice on ocean floors but this will only add to carbon dioxide production and be expensive.

expansion of nuclear fission stations

nuclear fusion converting hydrogen to helium like on the sun (at least 50 years away)