An epoch is a period where geological evidence of activity on the planet can be clearly seen in the layers of rocks. To put time into context the previous geological period was the Pleistocene epoch which lasted from 2.5 million to 12,000 years and was noted for its succession of ice ages and warm periods which cycle every 125,000 years. During the warm periods it was roughly the same temperature as today and 5C colder in the more common ice ages and the sea level would have ranged over 125 metres as water was locked up in ice or melted back into the oceans. CO2 levels ranged from 180 parts per million in an ice age to 280 ppm in a warm period. Evidence of this activity is clearly shown in rock and silt samples.
The Holocene epoch about 12,000 years ago during which the temperature has not varied more than 1 degree centigrade, CO2 remained at 280 ppm and sea levels have been very stable. It was during this period of stable temperature that humans flourished and spread further around the world and we have recorded history for most of it confirmed by archaeological digs.
Humans have always burnt the bush to regenerate plant growth and to make space for hunting and gardens and as this timing coincided with the Holocene epoch, I have always considered that the Anthropocene epoch commenced 12,000 years ago and that the two were the same. If it walks like a duck, it swims like a duck and it quacks like a duck then it’s a bloody duck. But apparently that’s not the case.
In order for the Anthropocene to be considered as a separate epoch there needs to be evidence in the layers of soil which can be clearly seen in thousands of years’ time. The whole process has to have evidence presented to a geological committee of peers and the evidence carefully considered before a decision is made.
Getting facts together indicates a start time of 1950 (when I was 10 years old) and this is because that was when modern human activity really took off. This is when the population expanded, water use and fertiliser use increased, ozone depletion started, there was an increase in floods, a big increase in paper production and car numbers, international tourism started and loss of the rain forests.
This activity is clearly shown with radiation dust from atomic bomb testing in the 1950’s, evidence is also in ice core samples with layers of carbon each year from burning coal and oil, evidence is in the sediment of ponds showing an increased number of floods and in the ocean floor with a layer of plastic.
Our activity is clearly shown in the samples taken from sites all round the world and we have changed the planet in ways that could not be anticipated when I was a boy and we really are in the Anthropocene epoch. 

A report on research by scientists in the Department of Physics and Astronomy at the University of Porto in Portugal drew some interesting conclusions about where climate change is heading.
The problem starts with the old story about a butterfly’s wings fluttering in the Amazon can affect the weather a continent away which is of course an exaggeration but to a degree that is what happens.
Mathematicians are constantly working with weather forecasters to develop computer models which take what is known about atmospherics and applies it to a detailed weather map complete with atmosphere pressure gradients and fronts. In its simplest form this would give a forecast for two or three days ahead but farmers, fishermen and many other industries and people are looking for longer periods.
If the old forecast used detailed information in squares of the earth surface which are 100 kilometres on each side, then to achieve a longer range forecast more information is needed and by the use of satellites, weather buoys, aircraft, ships and automatic weather stations forecasters are able to get squares down to one kilometre on each side. This is 10,000 times as much information and with all the information and calculations it requires some of the biggest computers on the planet.
Even this is not sufficient because there are slightly different ways of calculating weather which might give different emphasis to pressure, or clouds or wind strength or the upper atmosphere and so the forecasters might run fifty or a hundred different models to see what the differences are. If thirty say a different outcome is expected then that can be taken into account and a warning given.
If more information is available, say down to 250 meters on each side of the square, as it might over land where there are a lot of stations, then fuzzy logic can be applied. This is when the extra information taken into consideration in the main program but it becomes so vast that this entails leaving some of the information out so that fuzzy logic fills in the gaps.
Weather forecasts are not the same as climate change predictions but it does entail vast amounts of information being applied to known laws of physics and chemistry and what has happened in the past and then run foreword into the future and this gives us a fairly good idea of the future.
What the Porto scientists did was used was used phase transitions which is where a material, such as water behaves in a certain way when as a liquid but behaves differently when it becomes a gas after evaporation.
When this is applied to climate change the world is predictable to a certain point, like an increase of 3C, but then it swings violently and chaotically into severe storms or drought, and then returns to near normal for a while.
These swings are triggered by tipping points and when they are exceeded nothing is predictable again and the climate performs in a chaotic pattern which is outside our forecasting and comprehension.