Episode 74 - Decarbonization

Our Current Climate Trajectory

1995 was the first COP summit. At that time, atmospheric carbon was 363 parts per million.[1] Prior to the last century, the parts per million of CO2 in the atmosphere varied between 180 and 280 PPM.[2]

We are currently on track for 4.5 degrees of warming by 2100.[3] And if we do nothing, the planet could warm by as much as 8 degrees of warming by the end of the century.[4] Nobel laureate William Nordhaus estimates that there is a one in three chance that our emissions our emissions will exceed the UN’s business as usual estimates, meaning five degrees of warming or more.    

Putting Degrees of Warming in Practical Terms

David Wallace-Wells, The Uninhabitable Earth

“Because these numbers are so small, we tend to trivialize the differences between them—one, two, four, five. Human experience and memory offer no good analogy for how we should think of those thresholds, but, as with world wars or recurrences of cancer, you don’t want to see even one. At two degrees, the ice sheets will begin to collapse, 400 million more people will suffer water scarcity, major cities in the equatorial band of the planet will become unlivable, and even in the northern latitudes heat waves will kill thousands each summer. There would be thirty-two times as many extreme heat waves in India, and each would last five times as long, exposing ninety-three times more people. This is our best case scenario.

At three degrees, southern Europe would be in permanent drought, and the average drought in Central America would last nineteen months longer and in the Caribbean twenty-one months longer. In northern Africa, the figure is sixty months longer—five years. The areas burned each year by wildfires would double in the Mediterranean and sextuple, or more, in the United States.

At four degrees, there would be eight million more cases of dengue fever in Latin America alone and close to annual global food crises. There could be 9 percent more heat-related deaths. Damages from river flooding would grow thirtyfold in Bangladesh, twentyfold in India, and as much as sixtyfold in the United Kingdom. In certain places, six climate-driven natural disasters could strike simultaneously, and, globally, damages could pass $600 trillion—more than twice the wealth as exists in the world today. Conflict and warfare could double.”[5]

Eight degrees of warming would truly be a climate apocalypse.

There are immense stakes to keeping global warming as low as possible. For example, it has been estimated that an additional 150 million people will die from air pollution alone in a 2-degree warmer world, compared to 1.5 degrees.[6] By the way, 150 million people is 25 Holocausts.[7] And this is the best-case scenario.

Decarbonization: The Basics

Decarbonization is a big project. It means changing the way humanity operates so that we reach net zero annual global net carbon emissions. Net zero emissions can be achieved by (1) reducing emissions or (2) by increasing carbon sinks.

There are different views on when we need to decarbonize by. The Decarbonization Imperative suggests 2050, but if we want to limit warming to 1.5 degrees, the reality is that we may need to do it by 2030.

To hold global warming to 1.5 degrees, we need to hold CO2 concentrations below 430 parts per million.[8] The IPCC estimates that we have 400 billion tonnes of CO2 remaining in our carbon budget to have a 66% chance of keeping CO2 concentrations below that limit. That gives us until 2030 if we keep emitting as we are.

Once that carbon budget is expended, we will need to reduce annual global net emissions to zero from that point on.[9] The longer we wait to reduce emissions, the sooner net-zero day will arrive. Right now we are on the wrong track: our emissions are increasing roughly 0.5% per year.[10]

So, what does decarbonization really mean in practical terms? 

Visions for Decarbonization in Five Sectors

Decarbonization will mean removing greenhouse gas emissions from every way that we live our lives. But there are five sectors that contribute the most to our carbon budget, so in this episode we focused on those. They are: energy, transport, industrials, agriculture, and buildings.  We recommend The Decarbonization Imperative by Lenox and Duff to learn about the sectors that emit the most and technologies that are driving decarbonization. However, this book focuses mostly on economic policies, so it excludes some policy approaches—like green urban planning, congestion taxes, and free public transit.

References

[1] Malm, Andreas. (2021). How To Blow Up a Pipeline. New York: Verso.

[2] Lenox, Michael and Duff, Rebecca. (2021). The Decarbonization Imperative: Transforming the Global Economy by 2050. Stanford, CA: Stanford University Press.

[3] Wallace-Wells, David. (2019). The Uninhabitable Earth. New York: Penguin Randomhouse.

[4] Wallace-Wells, The Uninhabitable Earth.

[5] Wallace-Wells, The Uninhabitable Earth at p.12-13.

[6] Wallace-Wells, The Uninhabitable Earth.

[7] Wallace-Wells, The Uninhabitable Earth.

[8] Lenox and Duff, The Decarbonization Imperative.

[9] Lenox and Duff, The Decarbonization Imperative.

[10] Lenox and Duff, The Decarbonization Imperative.

Kyla’s Notes

More information on fusion from the podcast Unexplainable on their episode “How to Build a Star”
More information on nuclear from the podcast How to Save a Planet on their episode “Should We Go Nuclear?”
Robbie recommends the podcast Rural Roots to Climate Solutions
Ottawa’s Vintage Boom
Moving Away From Fast Fashion