Soaring CO₂ Levels - A Closer Look
In the previous post, we started scratching the surface of climate change, and the devastating effects greenhouse gases like CO₂ can have if unchecked. As we saw in the post, over the past few decades, the CO₂ levels have grown significantly and at an alarming rate since pre-industrial times. Continuing along the theme of awareness and knowledge gathering, in this post, we will analyze the CO₂ emissions across the cross-section of time. In a later post, we will investigate a geographical cross-section by understanding emissions from various countries across the globe.
CO₂ Levels - A History
We have already looked at the Keeling Curve (a reading of the global atmospheric carbon dioxide concentration, by Scripps Institution of Oceanography at UC San Diego) plotted over the past 10,000 years.
The past 800,000 years
The spike within the past 10,000 years is alarming. However, I wanted to understand the pattern across a much larger time horizon so we can see the levels between ice ages, to see if there is some precedent. Here’s the Keeling Curve over the past 800,000 years, a period that includes multiple ice ages separated by warm periods.
As you can see, prior to the First Industrial revolution in 1760s, CO₂ levels would stay between 200 ppm (in the ice ages) and 300 ppm (in the warmer periods in between). At the time of writing, the current CO₂ level has already breached the symbolic 400 ppm mark. It is currently at 415 ppm! If the current pace continues, we will reach a level of 450 ppm by the year 2040.
Excess CO₂ - A curse of the Industrial Revolutions?
Next, I was curious to see what the correlation was between the industrial revolutions and excess CO₂ concentration in the atmosphere. We have had 4 industrial revolutions, each period forming an extraordinary chapter in human development and advancement, massively transforming human lives. I am going to overlay these periods on the Keeling Curve shortly, but first, let’s look briefly into these game-changing events that shaped today’s society.
The first industrial revolution spanned the years 1760 to 1840 and led to massive penetration of water and steam power and mechanized factory systems, powered by coal as the preferred energy source. The second revolution (the technological revolution), from 1870 to 1914 (the beginning of the First World War), involved widespread adoption of railroad and telegraph networks, water supply and sewage systems. The vast telegraph and railroad networks led to open movement of ideas and people and triggered a massive wave of globalization. It also saw the introduction of newer technologies like telephone and electricity. The third revolution (the digital revolution) was from the late 1950s to the late 1970s and brought with it a systemic shift from mechanical and analog electronic systems to digital systems. This was primarily driven by the widespread adoption of digital computers. This officially marked the beginning of the Information Age.
The fourth industrial revolution, as first introduced in 2015 by Prof. Klaus Schwab, founder and executive chairman of the World Economic Forum, builds on top of the third (the digital) revolution but is distinct in three crucial ways: speed, scope, and systems impact. Here’s how. Speed. The revolution is evolving at an exponential speed compared to the previous ages. Scope. It is disrupting every industry and in every country. Systems impact. It is resulting in a complete overhaul of entire systems of production and management. This has been possible through breakthroughs in artificial intelligence, internet of things, quantum computing, energy storage, nanotechnology, biotechnology, energy storage, and autonomous vehicles.
Okay, so as promised, here is the Keeling Curve, with overlays of the various industrial revolutions. How correlated is the CO₂ concentration with each of these ages? Any guesses?
The first revolution has a mild correlation but it picks up in the second. The third revolution (the digital revolution) and the information age that follows recorded unprecedented levels of CO₂ emissions. This does not completely isolate the era of maximum impact because of a very interesting fact! The lifetime of the bulk of CO₂ in air is 20–200 years. Which means the excess CO₂ emitted during the 2nd revolution (1900s) would have a cumulative impact even a hundred years later. So, it is not just the information age but cumulative CO₂ contributions from the previous revolutions (recall, widespread coal adoption in the first and second revolutions)!
CO₂ Emissions - A 2019 Global Overview
At this point, we are going to draw a distinction between CO₂ concentration levels and annual CO₂ emissions. We have so far been analyzing CO₂ concentration levels but as I mentioned, it also has contributions of residual CO₂ from a century back! To isolate the problem and help understand it better, we will now shift focus to annual CO₂ emissions measured in billion tonnes (GtCO₂). Global CO₂ emissions from fuel combustion were largely stable from 2014–17, but started rising again in 2017. The growth was even faster post 2018 and this has largely been driven by strong economic and GDP growth and slower penetration of renewables.
Let’s look at the annual global CO₂ emission starting from 1990. The data for these graphs is from the IEA (International Energy Agency) report on 2019 CO₂ emissions. As is clear from the curve below, the numbers continue to rise (32.8 billion tonnes of CO₂ in 2017)! We are nowhere close to a net-neutral carbon emission world.
If we focus on the period 1990 to 2017, we see a 60% increase in CO₂ emission globally. But how has economic and population growth fared in the same time horizon? The silver lining is that the world GDP grew 146%, much higher than the 60% CO₂ growth. So, sustained economic growth is possible with the adoption of cleaner and energy-efficient sources, thereby reducing greenhouse gas emissions. The world population growth in the same time horizon is 42%, slightly lower than the CO₂ growth, thereby showing a very small increase in carbon footprint per capita from 1990 levels.
But the carbon footprint per capita does show something encouraging. Here is a plot of tCO₂ per capita across the time horizon in discussion. We see a dip from 2010 to 2017. When I first learned about the levels though, I was astonished that the average person in the world is responsible for 4.4 tonnes of CO₂ per year, that’s 12 kg (26 lb) CO₂ per day! The average person in the US clocks in a 3x higher carbon footprint, but more on that later!
Due to wider adoption of renewables and switch to cleaner energy sources, the global energy mix is diversifying as we see a steady transition out of coal into other energy sources at a global scale. We see the effect here as one can see the curve stabilizing from 2010 to 2017. Unfortunately though, the total CO₂ emission is what actually impacts the earth and the transition to clean energy needs to be more aggressive to stabilize the total CO₂ emissions.
Towards a low-carbon world
The energy sector drives 75% of the greenhouse gas emissions. If we are to achieve global climate goals, there is a pressing need for critical reforms in the energy sector. Mitigation efforts must target both energy demands and carbon heavy energy supplies, across all countries.
The Paris Agreement - 2020 and beyond
The historic Paris Agreement was adopted worldwide in December 2015 and is the first international (developed and developing countries) agreement that calls for worldwide climate mitigation efforts. The agreement has a long-term goal of limiting temperature rise to under 2ºC (3.6ºF) from pre-industrial levels. It also aims to pursue efforts to limit the rise to under 1.5ºC (2.7ºF). At a high level, by the end of the century it aims to achieve a net-zero emission world by balancing greenhouse gas emissions with carbon sinks to absorb and eliminate excess emissions. One of the key strategies in the playbook adopted by the EU is the 20/20/20 program; 20% reduction in CO₂ emission, increase of renewables market share to 20%, and increase of energy efficiency by 20%.
In future posts, we will explore the energy outlook of the world and some key regions including the US, and take a closer look at the penetration of various renewables (including solar and wind) in the last 5 years.
