Revision as of 03:01, 31 December 2022

Introduction

Once humans discovered how to use coal to produce steam to make machines do work (1780) the overall energy use by human society increased significantly.
Coal is created from the remains of dead plant material. The energy in the plant material originally came from the sun. This energy has been stored in the Earth for millions of years.
Early coal was easy to dig up. Steam machines gradually became more efficient.
The work output from burning coal was so large that Engineers had to use horses to explain work output and so the concept of horse power was invented.
Human work is the equivalent to 75 Watts
One horse power unit is the equivalent to 746 Watts (about 10 times more than humans)

This graph shows how the amount and type of fuel consumption has changed from 1950 to 2015.
It shows that the total amount of primary energy consumption by humanity has increased significantly.
And that we are still produce most energy from non-renewable energy sources [1]

In this graph we can see how surplus energy has been used over time.
Early humans only used the equivalent of 100 Watts of energy and this was mainly for their food provisions.
During the time of the Egyptians primitive agriculture increased our energy consumption to 600 Watts per person.
During the industrial revolution coal and steam engines allowed humans to increase energy consumption to 3,850 Watts
In modern times the energy consumption in countries such as the USA and Australia is 11,500 Watts [2]
The hidden cost associated with the large increase in energy consumption has been the concomitant increase in GHG emissions and the warming of the planet.

The amount of energy used by the average person in the USA and Australia in 2016 is equivalent to 100 x 100 Watt light globes.
By comparison, the energy consumption averaged for all humans on planet Earth is 26 x 100 Watt light globes*
In the short term rich countries could easily reduce energy consumption and allow poorer countries to increase their share of energy consumption, while still reducing overall energy consumption for humanity.

CO2 levels for the past 10,000 years have been stable [3].
However, since the start of the industrial revolution the levels of CO2 in the atmosphere have increased significantly.
Annual atmospheric CO2 levels are shown in the adjacent graph showing increases from 1960 to 2015.
Annual atmospheric CO2 levels are currently increasing by 2-2.5% per year.
As our energy consumption has increased so too have our CO2 emissions and the concentration of CO2 in the atmosphere.

There is the expectation that society will replace fossil fuel energy with renewable energy.
However renewable energy has the following drawbacks:
- Raw materials need to be mined and processed (e.g. copper, cobalt, lithium, nickel).
- Renewable energy assets are mostly produced with fossil fuels
- The Energy Return on Investment for solar PV and wind renewables is relatively low in comparison to coal and oil.
- Storage solutions such as batteries are resource intensive and also use fossil fuels in their production.
- 54% of renewable energy raw materials are on indigenous land [4]
- Renewable technology does not last forever and will need to be recycled and rebuilt.
The reality is that while increasing the amount of renewable energy we will also need to reduce energy and material consumption, especially in developed countries.
A decrease in energy and material consumption (degrowth) will have recessionary impacts for the economy but significant benefits for the Earth.

The reduction in CO2 emissions needs to be done quickly.
As we saw during the COVID years of 2019 and 2020, carbon emissions can be reduce by 7% in a single year if governments act quickly.
The following graph Tweeted by Gretta Thunberg shows the level of CO2 mitigation required to keep global warming to 1.5 degC (>66% chance).
If emissions continue at their current trajectory (around 420 Gt CO2 emissions per year) then the global CO2 carbon budget will be used up by 2030.

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 [[File:Screen Shot 2022-12-31 at 12.38.42 pm.png | 900px]]
+= Time is Limited =
+* The reduction in CO2 emissions needs to be done quickly.
+* As we saw during the COVID years of 2019 and 2020, carbon emissions can be reduce by 7% in a single year if governments act quickly.
+* The following graph Tweeted by Gretta Thunberg shows the level of CO2 mitigation required to keep global warming to 1.5 degC (>66% chance).
+* If emissions continue at their current trajectory (around 420 Gt CO2 emissions per year) then the global CO2 carbon budget will be used up by 2030.
+*
+[[File:Co2 Mitigation curvest Greta Thunberg.jpeg | 900px]]
 = References =