That site also shows our carbon budget. This is how
much CO2 that can be emitted into the atmosphere and still give us a
chance of remaining under 20 C warming. As of late March 2022 this
budget is a little under 1,060 billion tonnes. Other estimates concur with this
figure.
So, how much carbon do we emit each year? Although
emissions dropped in 2020 by about 5% (because of covid) we are now back to
emitting as much as we did pre-covid – roughly 36 billion tonnes per year.2
If you do the arithmetic and divide the carbon budget
by how much we emit annually then we have only a few months past 29 years
before we reach 20 C (and that assumes that we do not increase the
amount we emit – a depressingly unlikely possibility.) However, let us err on
the conservative side and say we have 30 years. That is, sometime in 2052!
What is to be done? Can ‘renewable’ energy save us?
Do The Maths
Let’s do a little bit more mathematics. (Apologies to
those who do not like maths. Hopefully, the following calculations are not too
difficult to follow.)
First, some background and provisos.
Often the ‘renewable’ options (e.g. solar, wind,
hydro, geothermal etc) are termed renewable energy. This is a misnomer.
Solar, wind, and hydro are used to generate electricity, which is one aspect of
energy. Thus, the term should more correctly be renewable electricity.
Other aspects of energy use include transportation, industrial use,
manufacturing, and agriculture.
In 2020 ‘renewables’ made up 5.7% of the global total
energy mix, with hydro contributing a further 6.9%.3 Of the global
total energy consumption, approximately 20% of it is in the form of
electricity. ‘Renewables’ contributed slightly less than 30% of electricity
production in 2020.4
This suggests that, all else being equal, if
‘renewables’ were able to contribute 100% to global electricity production,
then ‘renewables’ could expand by 333% (100/30 x 100.)
Thus, with the above background and the numbers, let
us do a mathematical thought experiment. What if we switched entirely to
‘renewable’ electricity today (yes, today, not in five years time, not even in
one years time, but now!)
If we did that, we could increase the contribution of
‘renewables’ to the energy mix from 5.7% to around 19% (5.7 x 3.33. From 30% of
electricity production to 100%.) This is an increase of 13.3% on the present
contribution.
But, before we do the calculation, there is one
further consideration to take into account. ‘Renewable’ does not mean
carbon-free. All ‘renewables’ have a carbon emission component when their full
life-cycle is considered. This is less than that for fossil fuels, but not
insignificant.
Each type of ‘renewable’ has different carbon
emissions, as does each different fossil fuel. ‘Renewables’ emit between 3 –
10% carbon equivalent of that emitted by fossil fuels. For the sake of
simplicity, let us assume a figure of 5%.
Theoretically, this represents a decrease in the
amount of CO2 equivalent from 36 billion tonnes per year to 32.8
billion tonnes (36 x (100 – 0.133) x 1.05)
Now, let’s see what that does to our carbon budget.
The arithmetic is straight forward. It is 1,060 ÷ 32.8 = 32.3 years.
What About EVs
Some readers may object that I have not taken into
account the contribution of EVs (electric vehicles) in the coming years.
A similar thought/mathematical experiment can be done
regarding EVs.
Beginning again with some background and provisos.
Transportation contributes approximately 20% of global carbon emissions.
Private cars, light trucks, and motorcycles make about 29% of all transport
(other sectors include heavy trucks, shipping, and aviation.)
At present, only cars, light trucks, and motorcycles
can effectively use an electricity source for motive power.
Presently the carbon emission efficiency of EVs versus
conventional (fossil fuel) vehicles is only about 25%.5 In other
words, over their life-time an EV can be expected to contribute around
three-quarters as much carbon equivalent to the atmosphere as does a
conventional vehicle. This is mainly because of the extra carbon emissions
involved in manufacturing.
Now, suppose that all (yes, every single one) private
cars, light trucks, and motorcycles were converted to EVs today. This would
represent a contribution of 1.5% reduction in carbon emissions (0.29 x 0.25 x 0.2.)
How much does this represent? Just 0.54 billion
tonnes.
Let’s now plug this into our calculations above.
Instead of 1,060 ÷ 32.8 we now have the equation 1,060 ÷ (32.8 – 0.54) = 32.8 years.
Just three years! That’s all – three years we gain by
switching to 100% ‘renewables.’
And that’s if: 1. We do it now (not possible) and 2.
We do not increase the amount of carbon we pour into the atmosphere from other
sources (unlikely).
OK, the mathematics may be imprecise, yet the results from
the calculations are within the bounds of possibility. If anything, we are
likely to gain less than three years, because of the two ‘ifs’ above.
One Final Rider
It will be noted that I have used the term
‘renewables’ rather than simply renewables. This is deliberate. I use the term
‘renewables’ to indicate that they are not renewable. To build, manufacture, transport,
and decommission solar, wind, vehicles, batteries and the other components of
these technologies uses finite resources. Plus, I have not even mentioned the
environmental and social costs and damages that ‘renewables’ bring.
The Question
The question then is: If we had it, what
would/could/should we do with the extra three years?
We could spend the three years devising different
questions. We could spend the three years thinking (as Einstein suggested)
differently. We could use a different thinking than the (mechanistic,
technologically-driven) thinking we have used to get us to this predicament.
How about instead of waiting for that three years, we
transform our thinking radically, and start asking questions related to how can
we decrease our dependence upon electricity, how can we reduce our use of
vehicles?
How can we de-grow?
Notes:
1. Mercator Research Institute on Global Commons and
Climate Change. https://www.mcc-berlin.net/en/research/co2-budget.html
accessed 28 March 2022.
2. https://www.statista.com/statistics/276629/global-co2-emissions/
accessed 28 March 2022
3. Statistical Review of World Energy 2021 p12
4. www.ourworldindata.org
Accessed 29 March 2022.