According to the IPCC, limiting warming to 1.5°C requires: 

• CO2 emissions decline by about 45% from 2010 levels by 2030 and, 
• reaching net zero around 2050. 

For a 66% chance of limiting global warming to below 2°C, it requires:   

• 25% decline in CO2 emissions by 2030, and,  
• reaching net zero around 2070.  

First, let’s assume these are the required targets, and acknowledge that some researchers are finding different values, such as a recent article published in Nature in 2021 that found that we may already have passed 2°C with current GHG levels. One just needs to look at Figure 1 to see that a 45% reduction in GHG emissions is unrealistic.  This would be equivalent to eliminating both coal and oil related emissions within 10 years.  

        

Figure 1: Breakdown of GHG emissions by source and sector 

There is no indication that the world is ready to make the drastic changes required to achieve our 1.5°C mitigation target.  Politicians tend to be very dishonest in terms of what it means to achieve this target. We have examples like Canadian Prime Minister Trudeau advocating for the 1.5°C target at the global climate meetings, yet turns around and spends billions of dollars to buy the Trans Mountain pipeline that commits Canada to decades of increased oil production levels. Trudeau was quoted as saying: “No country would find 173 billion barrels of oil in the ground and leave them there”, which is precisely what will be required in order to achieve our global mitigation targets.  

It doesn’t take much to see that limiting warming to 1.5°C is unrealistic. Now I want to examine if the 2°C is any more feasible. I want to start with some positive trends. First, we can see from Figure 2 that all of our global efforts to increase energy efficiency has led to significant declines in the energy intensity of our economy. 

Figure 2: Decreasing energy intensity of our global economy 

In addition to increasing our energy efficiency, we have also had a drastic increase in renewable energy generation as shown in Figure 3. We see than from 2010 to 2015, electricity produced from renewable sources doubled from 0.8 to 1.6 trillion kWh. 

Figure 3: Increase in global renewable energy production  

We would not see these significant trends in both energy efficiency and renewable energy generation if it wasn’t for significant global efforts to reduce GHG emissions. The charts are showing the result of 20 years of annual COP meetings of global leaders.  Despite these impressive gains in efficiency and renewable energy, it has not resulted in a measurable reduction in CO2. In fact, global CO2 emissions have continued to increase.  As Figure 4 shows, despite all the COP meetings, the concentration of CO2 in our atmosphere is not only increasing, the rate of increase continues to climb.   

Figure 4: Atmospheric CO2 concentrations shown to be increasing despite annual COP meetings 

There are many factors that are making it difficult to achieve a decline in global GHG emissions. Two of the most significant drivers is our continued growth in population (Figure 5), and our global economic model that is based on exponential growth (Figure 6).  Figure 2 showed that our economy is becoming more efficient. Every 10 years, it requires roughly 10% less energy to generate $1 of GDP. However, Figure 6 shows that every 10 years, our global GDP increases by around 25%. That is, our economic growth rate continues to outpace the growth rate of energy efficiency. The result, as shown in Figure 7, is that our global energy demand per capita continues to increase at a rate of roughly 10% per decade.  The energy use per person is increasing, and the number of people is also increasing at the same time. In the next 30 years, we will add 2 billion people, a 25% increase in population. Whereas, at the same time, we are required to drastically reduce our overall GHG emissions 

Figure 5: Global population projections 

Figure 6: Global GDP continues with a steady growth  

Figure 7: Increase energy use per person 

As shown in Figure 3, renewable energy generation has increased dramatically; growing at approximately 15% per year between 2010 to 2015.  This was still not enough overall growth to meet the increase in global energy demand.  We see from Figure 8 that coal and natural gas generated electricity has grown to meet the increasing demand for electricity.  Figure 9 shows the overall mix in global primary energy use.  Solar and wind are still only a drop in the bucket of overall global energy use.   

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Figure 8: Global electricity generation by source 

Figure 9: Global primary energy consumption  

Here I want to do a back-of-the-envelope analysis to see what it would take to make solar, wind and modern biofuels the only source of primary energy. Looking at Figure 9, let’s estimate solar, wind and modern biofuels at 10,000 TWh/yr, and the remaining energy use at 150,000 TWh.  Using the following assumptions: 

• Energy growth rate at 1.6% per year to maintain economic and population growth 
• Additional growth required for the embodied energy going to produce the new renewable energy 
• EROI for the renewable energy averages 15, that is, over its life, the technology will generate 15 times more energy than it took to manufacture it.  

• Renewable energy has a lifetime of 25 years 

Meeting the 1.5°C target and reducing the 150,000 TWh by 40% by 2030, would require a sustained annual growth rate of 31% per year for the solar, wind and modern biofuels. This sustained rate of growth is not feasible. By year 10, we would need to be adding 34,000 TWh/yr of additional renewable energy capacity every year, which is roughly equivalent to the current total amount of natural gas energy used. The amount or resources required to build all those renewable energy systems would be enormous, with 40% of the renewable energy added to the grid would simply be going into generating the energy required to build the new capacity. If we achieved that growth rate, by 2033, we would have eliminated all other energy use and would be 100% renewable.  

Meeting the 2°C target and reducing the 150,000 TWh by 25% by 2030 requires a sustained annual growth rate of 26% per year for solar, wind and modern biofuels.  As shown in Figure 10, we only actually start seeing reductions in the other energy use after 5 years, when the additional renewable energy starts to be able to meet the growth in energy demand.  Again, the logistics of sustaining a growth rate where we add 26% renewable energy capacity every year would be difficult to maintain.  

Figure 10: Impact of renewable energy growth rate on reducing fossil fuel use.  

If instead we aimed to simply reduce other energy use by 2050, this would require a more modest rate of growth of 12% per year. However, at that lower rate of growth, our actual fossil fuel consumption would continue to grow until it peaked in 2031, and only start achieving meaningful reductions past 2035.   

If we mobilized globally and managed to achieve an aggressive growth rate for renewable energy approaching the 26% to 31%/year for the next 10 years, at the same time, globally we would have to agree on a sensible approach to phase out fossil fuels. All of this additional renewable energy would need to complete against fossil fuels.  Supply-and-demand pressures would likely lead to a reduction in the price of fossil fuel energy, as we have seen with cheap natural gas prices in North America.  How do we stop people from buying this cheaper energy?  If energy becomes cheaper, the tendency is generally to increase consumption and grow demand.  How can the more expensive renewable energy compete against cheap fossil fuels?   

How can we convince countries like the US, Russia, Saudi Arabia to leave oil in the ground when even a progressive prime minister in a liberal government in Canada says that: “No country would find 173 billion barrels of oil in the ground and leave them there.”  Same goes for all of the coal producing countries, including China, India, and Indonesia.  In Alberta, where most of Canada’s oil is produced, there is pressure to start increasing coal production to offset the decline in income from lower oil prices. 

In order to achieve our GHG mitigation targets, we need a number of paradigm shifts:  

• Global agreement on capping and quickly reducing overall fossil fuel production.  

• Need a new economic system that doesn’t need growth to function.  
• Need to shift away from consumerism. 
• The amount of resources consumed per capita needs to significantly reduce, and be more equitably distributed amongst the planet’s inhabitants.  

It’s not just a matter of planting more trees, building more nuclear reactors and renewable energy.  Until the global discourse on GHG mitigation becomes more serious, we will continue to see continued growth in overall CO2 concentration in our atmosphere.