Saturday, April 22, 2023

Three videos from Vox for Earth Day

Happy Earth Day! I'm celebrating today with three videos from Vox about fighting climate change, both by reducing emissions and actually removing greenhouse gases.* I begin with the video I plan on showing my geology students next week and my environmental science students this summer, How solar energy got so cheap.

Cheap solar is a policy success story.
Since 2009, the price of solar energy has come down by 90 percent. That’s no accident. It’s the result of policy interventions from the US to Germany to China.

As policy analyst Gregory Nemet puts it, “No one country is responsible. It was a relay race rather than a competition.” The global flow of knowledge, people, technology, and policy helped bring down the price per watt from more than $100 in 1976 to less than $0.50 today, according to this analysis from the folks at Our World in Data...

If we can learn the right lessons from solar’s success, it could help us develop and deploy the technology we need to keep our planet habitable and avoid the worst impacts of climate change.
That's good news, almost enough to make me post Professor Farnsworth — almost.

I'm also tempted to show The big problem with cement, and how to fix it to my students.

Concrete emits a ton of carbon. Here's how we get it to net-zero.
Cement accounts for 8 percent of our global carbon emissions. It’s also an incredibly difficult material to do without: It’s the glue that holds together the rock, sand, and water in concrete. And concrete is the building block of the world: It’s in our buildings, our streets, our sidewalks, and our infrastructure. Aside from water, there’s no material on earth we use more of.

In order to get to net-zero CO2 emissions by 2050, we’ll have to address how we build and how we make cement. Because cement production is so closely linked to urbanization and development, China accounts for a vast majority of today’s cement-related emissions. Other countries with more development in their future will need to emit more emissions to produce cement, too. All that means the whole world needs to figure out how to create cement without the emissions. This video goes into the steps developed by researchers for how to get there.
I lecture about cement and concrete in my classes, both as the most extracted earth materials and how concrete makes nuclear power requires a lot of both, making it less of a solution for climate change than it otherwise would be. Both of these make this video another candidate to show my students.

The second video lists carbon capture and sequestration as part of the solution to the problem of making cement and concrete production and use carbon neutral. The third Vox video I'm sharing today explores that, The tricky plan to pull CO2 out of the air.

Will carbon dioxide removal work? It has to.
In recent years, over 70 countries have committed to net-zero carbon emissions, aiming to become carbon neutral by mid-century. The 2015 Paris Agreement aimed to keep global warming below 2 degrees Celsius and ideally limit it to 1.5 degrees above pre-industrial levels. Despite global efforts, emissions are still rising, and achieving the 1.5-degree goal has become increasingly difficult.

Most pathways to keep warming below 2 degrees, and eventually return back to 1.5 rely on negative emissions, which involve pulling carbon dioxide from the atmosphere using carbon dioxide removal (CDR) methods like enhanced weathering and direct air capture.

However, these techniques are still in early development stages, and require land, energy, and money. Critics argue that relying on CDR implicitly encourages governments and companies to postpone necessary emissions reductions because counting on CDR now means relying on future generations of leaders to deliver on those promises. Preventing emissions is broadly less costly than cleaning them up after the fact. But even with dramatic cuts to emissions, experts say some amount of CDR will still be necessary.
I'm not sold on whether highly technological methods of doing this will work. They're certainly not ready for prime time, which is why I'm not planning on showing this video to my students. I'm more confident about planting trees and turning carbon dioxide into stone, two "Nature knows best" solutions. Just the same, we need to try all of them.

*Vox is also uploading videos about A.I. That's even more of a science fiction is now idea, so I might return to it. Stay tuned.



    Great set of videos! The concrete video only looks at the carbon footprint of actual production of cement not the carbon footprint all together. When you total in all the environmental costs of concrete such as mining aggregate, transportation and all manufacturing stages its much more then 7-8 % of the global emissions always talked about.

    A neat rabbit hole to explore about concrete is Polymeric concrete. Google it and dive in. It is what the Romans and Egyptians used. It is far superior to our modern concrete Look at the Roman structures like the Pantheon (largest unsupported dome ever) or the harbors they built. At almost 2000 years old and still in use it's a stark contrast to our modern concrete that is lucky to have a life of at best 100 years.
    Look at some evidence now that has been proven with an electron microscope that much of the great pyramids are also formed/made out of a similar substance and it can make your head spin. Its funny that modern humans are so narcissistic in thinking we are masters of our environment and building sciences but we can't really 100% figure out how they made the simplest thing like their concrete. Maybe one day it might be the answer we have been searching for all along to make it this basic building material more sustainable and longer lasting. If anything it WILL cut down on the large carbon footprint of concretes production as there were no kilns to make lime or clinker. We will see.....i guess......!!!

    1. And happy Earth Day to you, too!

      Thanks for your contribution! You're absolutely right about both your points. The Vox analysis doesn't take those features into account. Also, Roman concrete is superior to modern concrete. At least we're starting to understand why.