There’s More to Climate Change Than Carbon: The Second Front
Background
Climate change is now a full blown “climate emergency,” with the focus stronger than ever on the seemingly unstoppable rise on atmospheric carbon levels. The rampant burning of fossil fuels over the last few centuries has awakened natural feedback loops. Vast stores of methane, a gas 30x as potent at CO2, now bubbles up from what had been for tens of millions of years a secure frozen prison in the arctic tundra.
Today, at only 1°C over pre-industrial global temperatures, weather patterns have become so distorted and extreme that floods are flood-ier, droughts drought-ier, and wildfires burn ever more intensely. The Australian bushfires 2020 have pumped nearly a trillion tons of carbon into air, effectively doubling the continent’s emissions for the year. Meanwhile in Africa, last year’s intense rains have unleashed massive clouds of locusts and with them the threat of severe famine. What transforms climate change into a full-blown emergency are cascades of collateral catastrophe.
We are on track for for a 3° to 5° C rise in temperature by 2100 if dramatic action isn’t taken immediately, according to the World Meteorological Organization (UN). Frying pan meet fire.
Yet as the costs of climate change become more apparent and the dangers more tangible, the legacy of the Paris Agreement has devolved into political posturing and missed targets. The outrageous lies of climate denialists put the entire world — the future itself — at risk.. Science is based on facts and data. And the relentless ratcheting up of atmospheric carbon levels, neatly charted for over half century on Keeling’s infamous Curve, now breaks records almost by the day.
The Second Front
But carbon isn’t the only driver of climate change. Nor is CO2 the only — or even the dominant — greenhouse gas. That would be water vapor, which cycles through the atmosphere much faster and acts more as an amplifier of climate change. There is a feedback loop at work here, too: The warmer the air, the more water vapor it can hold, which heats things up even more. That, in turn, accelerates glacial melting, so water that had been locked up in ice pours into the ocean, raising sea levels, and also evaporates into the air. The Earth’s atmosphere now holds about 7% more water vapor than it did at the start of the industrial revolution.
This means that to steady the climate, it isn’t only carbon that needs to be returned the ground. Water must be returned to its pre-industrial hydrological cycles. This opens up a vast second front in the battle to slow — and possibly reverse — climate change.
We live on a blue planet, notes Australian soil biologist Walter Jehne. Water governs 95% of the planet’s heat processes, while carbon drives roughly 4%. To focus only on carbon, then, not only misses the point, it misses an opportunity.
Hydrology is intimately tied to land use and to the living skin of our planet: the soil’s microbiome. “That’s the point of our agency,” says Jehne. To pave or not to pave. To till or not to till. To clear cut or to plant. “It’s not (only) how many raindrops we get…but just as important what happens to every raindrop.”
Carbon and water are dance partners. For each gram of carbon, soil can absorb 8 grams of water, creating what Jehne calls “the soil carbon sponge.” Build up the sponge — sequestering more carbon in the sail and returning water to the land — and those cascades of climate catastrophe can transform into cascades of verdant goodness.
This is how to get back to Eden.
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At the same time that massive amounts of carbon have been wafting skyward thanks to the mass burning of fossil fuels, the Earth’s surface has been almost completely transformed by agriculture, deforestation, industrialization and urbanization.
Scientists estimate that at least a third of world’s agricultural land is severely degraded, with a mind-numbing 24 billion tons of top soil lost each year. Much of that is squandered through modern farming practices dependent on petrochemicals — fertilizers, pesticides, herbicides and fungicides — that literally kill the soil’s natural microbial ecosystems. Without a healthy microbiome, the soil’s ability to sequester the CO2 that plants take in through photosynthesis is diminished. The soil becomes less absorbent as well, with rain more likely to run off rather than sink in, and carry along with it a toxic brew of petrochemicals.
Regenerative agriculture, sometimes called “carbon farming,” is designed to return life to the land. The key is to minimize soil disturbance. Seeds are “drilled” into the ground (no till) rather than planted using a plow. Plowing (tilling) releases carbon and nitrogen stored in the soil, which turns into o the greenhouse gases CO2 and NOx when exposed to air.
In regenerative agriculture cover crops are planted in the seasons between cash crops so that soil is always covered, just as it is in nature. This also provides habitat for insects, birds and other animals. A richer the biodiversity is below ground means a more robust ecosytem above the surface.
Cash crops are planted in rotations of at least three crops in order to better manage crop-specific pests. These insects and pathogens can typically survive an off year, which makes the standard two-crop rotation of corn and soy so prevalent in the US vulnerable. Adding at least one extra crop to the mix naturally tamps down pest populations.
Regenerative farming dramatically cuts down on the need for fossil fuel inputs, with savings that go directly to the bottom line. As the land recovers and the soil microbiome begins to thrive, the ground is able to hold more carbon, which allows it to store more water. The farm becomes more resilient to flood, drought and heat. Now imagine this at scale: The land returns to health and the climate begins to steady. The transition from conventional to regenerative farming takes a few years, but the pay-offs are game-changing.
Beyond the farm, vast amounts of CO2 can be sequestered by planting trees and restoring grasslands and wetlands, which again also improves hydrology and boosts biodiversity.
In cities, climate-friendly landscaping boosts resilience and saves money: It lessens both the risk and the costs of floods, droughts and heatwaves, while at the same time sequestering carbon. It can take on all kinds of forms:
- switching out chemically-dependent lawns for native plants
- setting aside more land for parks, forest preserves and prairies
- using permeable pavements that allow rain water to percolate into the ground rather than run off.
It simply isn’t enough to focus only on decarbonization. Cities and their sprawling suburbs can improve carbon sequestration, hydrology and biodiversity, too. More birds, more bees, more better.
Putting more atmospheric carbon back into the ground, along with reducing fossil fuel emissions, can also help marine ecosystems bounce back. Oceans, lakes, rivers and streams are natural carbon sinks, but over the last few hundreds they have absorbed so much CO2 that water has become acidified, altering biogeochemistry and making a hash of food webs.
Reductionist Thinking in a Systems-driven World
The headlines are full of one-note fixes: Plant a Trillion Trees! (WEF). Save the Whales! (IMF). Giant Machines that Suck Carbon Right out the Air! (Bill Gates). These are not bad ideas, but they won’t — they can’t — solve the problem.
Planting trees is wonderful as long as they are the right trees in the right place and are planted in ways that encourage the development of vibrant ecosystems.
Saving whales — and the vast numbers of carbon-sequestering phytoplankton that feed off their copious poop — well, yes, please. The more whales, the better! But when IMF economists compare the sequestration potential of whales to that of rainforests in order to prioritize climate-friendly investment, they miss the point: You can’t have whales without the rainforest, which plays a critical role in the global circulation of water. Lose the rainforest and the oceans will feel it.
Even if a carbon-sucking machine could vacuum up as much carbon as “40,000 trees,” trees do a lot more than sequester carbon; and carbon isn’t the only greenhouse gas. If the CO2 is injected into nearly-spent natural gas and oil wells in order to extract more gas and oil, then the whole exercise is counter-productive. Yes, the CO2 from the bonus fossil fuel could eventually be sucked out the air by a giant machine, but carbon neutral doesn’t mean climate-friendly. There are still all those emissions of NOx, SOx, methane and particulates to account for. The math is clear.
More to the point, the carbon is actually needed in the soil, not sealed in a well.
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The good news is that there isn’t one solution to climate change. Nor do we need to wait for a fancy techno-fix — or even for foolish politicians to be guided by science. Both would help. But we have the power to begin shifting the trajectory away from a “climate emergency” right now.
Emissions must be reduced. That’s a given. (Note that efficiency has had about 30x the impact of renewables in terms of “keeping it in the ground.” Reducing demand makes it easier for renewables — which are increasingly cost-competitive with fossil fuels — to replace them, e.g, fewer solar panels and wind turbines are needed to get the energy job done.)
Then follow the water, the microbes and nature. The instructions for how to steady the climate and restore the wealth of the land are all around us.
Go to Mars for the adventure. But to figure out how to make a planet habitable, we have a planet-in-need right here.
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Read more about the environment and climate issues in The Primer.
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