Empirically Yours

Between Two Trees


Fir: Hey Cedar, have you heard anything lately from your cousins, the white and black spruce trees in Alaska? I’m getting worried that they are dying because of changes in the climate up there.

Cedar: Well they’re your cousins too. All I heard is that because of successive years of warm temperatures along with much less rain and snow than usual, the beetle infestations that killed the cousins out on the Kenai Peninsula have now spread to Southcentral Alaska, around Anchorage. The trees are dead or dying on more than 1 million acres — bigger than the state of Rhode Island and nearly the size of Delaware. That’s a lot of trees…just gone.

Fir: Sounds like the Alaskan spruce forests are becoming another casualty of a warming climate driven by greenhouse gases in the atmosphere, especially carbon dioxide.

Cedar: I rather like the higher carbon dioxide levels. It helps me grow faster, as I pull it in from the air and turn it into sugars, cellulose, and everything else that’s me, using photosynthesis driven by sunlight.

Fir: Yeah, well your bark isn’t loaded with beetle larvae yet, chewing their way into your cambium layer like they’re doing to our cousins in Alaska. Considering how fast the climate changed and the trees are dying, there isn’t time for the emergence of new spruce trees that can tolerate the warmth and lack of water and resist the beetles.

Cedar: Do you reckon that excess carbon dioxide in the air is the culprit?

Fir: Yes, carbon dioxide derived by the fact that Homo sapiens (H sap) continue to burn the bodies of extinct plants and animals for transportation, electricity generation, and industrial processes such as making steel, cement, even fertilizer. All of this burning dumps tens of billions of tons of carbon dioxide into the atmosphere each year. This means that H sap’s excessive use of fossilized carbon-rich material is changing everything.

Cedar: Wait … they just dump this CO2 into the atmosphere, without recycling it? Without any attempt to remove it? Long-range, this is scary. Given that CO2 in the atmosphere traps heat, global warming is inevitable. It’s a simple consequence of the physics of how CO2 interacts with light.

Fir: I wonder why they don’t simply use sunlight to make electricity and pull CO2 out of the air, the way we do.

Cedar: There are two H sap companies that have a process to pull CO2 from the air, not by photosynthesis, but by a reversible reaction with strong alkalis like sodium hydroxide. They call this direct air capture. The two companies, one in British Columbia and the other in Switzerland, have demonstrated that it works, quite well in fact. The problem is that there is no market for the huge amounts of CO2 that need to be removed. But if the direct air capture of CO2 is powered by renewable solar or wind electricity and then pumped into disposal wells drilled into rock such as basalt, it is chemically bonded to the rock and it stays there permanently. They call that carbon capture and storage or sequestration. A carbon tax could help pay for direct air capture and permanent burial, but that would take political action, which isn’t likely. Some people are aware that climate change is having big effects on trees and animals but other H saps say it’s all a hoax. H sap is a very conflicted species, with a tragic inability to anticipate the future realistically or to deal with future changes that have serious consequences.

Fir: Soon though, H sap won’t be able to ignore the changes.

Cedar: Why does H sap ignore us? Fixing carbon is what we do all the time, pulling CO2 out of the air by photosynthesis. Why don’t they simply plant more of us trees?

Fir: Yes, that could help, but for a meaningful effect, it would have to be done all over the world, and it would take hundreds of years for the new trees to soak up enough CO2 to return the climate to the way it was, say, 50 years ago. I hope that’s not too complicated for you.

Cedar: Fine. So, if they want to fix carbon like we do, why don’t they grow chloroplasts in their skin and start photosynthesizing, like we’ve been doing for millions of years? Fir: That wouldn’t work for H sap, since we trees absorb red and yellow light but we don’t use the green light. So, the green is transmitted back out and our leaves appear green. If H sap fixed carbon the way we do, their bodies would appear green — and they associate that color with nausea and sickness.

Cedar: Whatever.

Richard Gelinas, Ph.D., whose early work earned a Nobel prize, is a Senior Research Scientist at the Institute of Systems Biology. He lives in Lakebay.