Reducing Carbon: the Simple Math

6 min readDec 9, 2021

Here’s the #1 way we could go “net zero” very soon, doing the best we can for our planetary life-support system. This piece synopsizes some of that math.

This article is an explainer for the updated math in my piece The Value of Biosphere Earth, pt. 7: Carbon.

*ACTUALLY, I MADE A MISTAKE. I assumed The Glasgow Forest & Lands Declaration’s carbon reduction estimates were separate from “Smarter Crops & Meat” — aka, converting the world to Regenerative Agriculture. As Drs. Chazdon and Lawrence advised, and I just fathomed, “we don’t know what overlap might exist between Glasgow and Regenerative Ag” — because the world’s currently degenerative agricultural systems (as in life-destroying), are the #1 driver of deforestation emissions.
OK, GOOD. We’ll take Glasgow all the way out, then. And from there we have total clarity: converting the world to a Regenerative Agricultural system, alone — which is a profitable, food-commodity-and-jobs generating foundational element of everything important to us — doing that alone, would stop us from entering into catastrophic climate change. Forget Mars. Mission: Earth.
Here’s a quick fix to this essay. The other pieces will be updated appropriately. Among the exceptionally positive aspects of this clarification, is the reality that prioritizing conversion to a globally-Regenerative Agricultural Economics would open the way for additional regenerative and stewardship economics and integrations worldwide.

Terminology
CO2 = Carbon Dioxide
CO2e = Carbon Dioxide equivalents
Gt = a Gigaton, one billion metric tons
/year = per year

Saving the Climate: this Decade

Last week I posted an article on recent research, re: how much Carbon Dioxide equivalents (CO2e) could be avoided and absorbed from the atmosphere this decade and century if we: a) fully achieve the COP26 Glasgow Leaders Declaration on Forests and Land Use, b) make some cost-effective changes to the way we manage crops and meats, and c) protect and restore Earth’s most bio-rich land ecosystems.

The 2021 UN Gap Report, released in October, tells us the world needs to reduce greenhouse emissions by up to 28 billion tons CO2e, per year, by 2030 to avoid catastrophic global warming. My report last week showed a maximum potential of -29.77 billion tons CO2e, per year, by 2030, from biospherically-regenerative emissions reduction — about 106% of the top end reductions needed.

Here’s the simple tally for that math:

Here’s a detail of what’s in the simple tally:

The Glasgow COP26 forests and lands Declaration calls for ending and reversing deforestation and land degradation by 2030. 137 countries committed to these changes last month. World Resources Institute recently calculated how much CO2e could be reduced from the atmosphere by fully achieving the Declaration, based on several authoritative studies. I use WRI’s numbers. So, in the graph above “Glasgow” line 1 contains maximum potential avoided emissions from bringing an end to deforestation plus maximum potential absorbed emissions from preserving those forests. “Glasgow” line 2 shows an estimate for maximum potential absorbed emissions from establishing protected regrowth on 100s of millions of acres of carbon-rich lands, forests, peatlands, and coastal wetlands, in keeping with the Declaration.

For “Smarter” I summed maximum potential Carbon and Methane emissions reductions from just eight sectors in the study Contributions of the Land Sector to a 1.5°C World (Roe, et al, 2019). Two of the greatest emissions reduction potentials here come from less waste and more soil care. These are profit-enhancing / cost-reducing strategies farmers and ranchers can implement with greater know how; they typically do not require heavy financial investment.

What’s more, improving rice cultivation and cattle feed reduces Methane emissions by about 2 Gt per year. Methane is roughly 80X more potent as a greenhouse gas than Carbon Dioxide and therefore critical to stopping and reversing extreme global warming. Making these changes to cattle feed and rice cultivation is one of the only ways to reduce Methane emissions.

Saving the Climate: this Century

In addition to the two studies above I reference two scenarios shown in Strassburg, et al, 2020. This study highlights the gargantuan greenhouse reductions and low costs that can come from saving and restoring Earth’s most biodiversity-rich habitats.

The IPCC stated in its 2018 special report on the climate that the world needs to remove at least 730 GtCO2e from the atmosphere before the end of this century. Strassburg, et al shows, once again, that maxing-out the best we can do for life-support system integrity on lands could provide -631.8 Gt CO2e reduction this century; that’s 86% of the emissions reductions required to stop and reverse catastrophic climate change, which simultaneously protects more than 70% of today’s most threatened species from extinction.

Here is that simple tally:

Taken from Global Priority Areas for Ecosystem Restoration (Strassburg, et al, 2020) and using their rates of CO2e absorption for “first 66 years” of natural regrowth.

It’s important to note that the costs associated with this CO2e reduction strategy are $10 to $15 a ton. Technologies like direct air capture currently cost somewhere in the range of $600 a ton to absorb CO2 from the atmosphere and require immense industrial manufacturing and energy to run. Technologies like BECCS (“BioEnergy with Carbon Capture and Storage”), heavily favored by the IPCC until recently, literally don’t exist. Meanwhile, Earth’s forests and soils have a multi-million year track record of self-management, generative productivity, carbon absorption, and climate resilience.

Summing Up

These 10 strategies could get us out of the global warming catastrophe by 2030 (-37 GtCO2e of -28 needed):

Stopping deforestation in 137 countries
Starting forest, peatland, and wetland restoration on 711 million acres of degraded ecosystems
Improving cattle feed
Improving rice cultivation
Improving soil carbon sequestration
Improving biochar carbon sequestration
Reducing food waste
Reducing agricultural waste
Reducing beef consumption
Improving nutrient and manure management

And this one strategy could absorb enough CO2e to radically drawdown global warming this century (-631 GtCO2e out of roughly -730 needed):

Protecting and restoring the habitats of +70% of the most endangered species on Earth.

There are many additional biospherically-regenerative CO2e emissions reduction and absorption strategies available. See “Additional Drawdown Opportunities” in this post for a list of ten other top candidates. We’re going to need all of them as human population and consumption continue to increase. But, imagine how bright our future could be with a robust global biosphere and stable temperate climate.

I like to say, we need a wilderness-based, technological future. Not the other way ‘round.

Considering the necessity of ecosystems and the local and global moisture benefits of intact land ecosystems, things no technology can provide at scale, there is no greater pathway for stopping catastrophic global warming and stabilizing Earth’s climate than doing the best we can for our planetary life-support system, Biosphere Earth.

Thanks for reading.

Scientific Citations

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