Global Warming: Can we Solve it in Time?

Back of the Envelope Calculations

To avoid a 2 degree temperature increase, we must reduce carbon emissions by 75% within 2050. That is assuming the population will be 10 billion then and our climate models hold water.

I’d like to do some back of the envelope type of calculations to see if it is plausible for us to solve this problem.

So we got roughly 30 years to solve the problem. Is that enough time?

As of 2017 only 1.73% of electricity generation is solar and 4.4% is wind based. That sound very little after so many years of pushing renewables. Given that world wide electricity demand grows 4–5% each year that does not seem to make a dent.

However it is easy to underestimate the power of compound interest. The last numbers for solar is 35% growth per year. Wind was at 17%. That is very rapid. Over time that makes a big difference. Of course these numbers will vary over time. But wind in its lowest year had a growth of 10%.

Lets look at how much bigger the wind and solar generating capacity can get in 30 years.

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You can see that within 14 years at 35% growth, solar power will have multiplied 100 times. That means if solar starts at 1% of total power generation, it takes just 14 years to achieve the present total power generation in the world.

If we are more conservative and assume 16%, which is closer to the growth rate of wind power, we will get there in roughly 30 years.

Of course neither start at just 1% and power consumption does not stand still. Lets look at what power consumption will be in 30 years.

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Depending on whether we expect 2% or 4% growth in energy demand per year, we can expect total consumption to roughly double or triple. Out of this total electricity demand, about 60% is in fossil fuels. This is the electricity generation we got to replace.

In this regard, it certainly looks doable.

There are 1.2 billion cars on the road today. If we look at the growth of electric cars over the last years, we can see an exponential development. Doing a simple extrapolation of the last years development we get this graph.

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If the current trend continues, then all cars are electric by 2027 or so. Of course this is not realistic. A trend cannot be exponential indefinitely. This is just a back of the envelope type of calculation. I am not a statistician.

This is more about answering the question, of whether current development trends are fast enough. They clearly are. The progress we are seeing today is impressive. How long they will hold is the question.

It will also clearly require more electricity production. The estimates seems to be 18% increase in generation and a 30% increase in installed capacity.

However if Solar continues to grow at 35% per year then that is not much of an issue. We are just talking about 1 year extra of solar expansion.

Of course this is more about theoretical possibilities. With that much solar it will represent significant investments and significant raw material requirements.

Don’t take these numbers too serious. There are way better analysis of this out there. I just wanted to get a sense of how fast or slow current development is.

Geek dad, living in Oslo, Norway with passion for UX, Julia programming, science, teaching, reading and writing.

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