In early February, Sen. Ed Markey (D-MA) and Rep. Alexandria Ocasio-Cortez (D-NY) introduced the Green New Deal (GND), a sweeping resolution that addresses the dual challenges of income inequality and climate change, and the first government policy document aimed at curbing climate change as one of its goals.
This is significant. The United Nations Intergovernmental Panel on Climate Change (IPCC) report released in October 2018 stated that there will have to be some removal of carbon dioxide (CO2) from the atmosphere — the first and most vital step in restoring the climate — in order to avoid the very worst impacts of climate change (including massive die-offs of coral reefs, flooding, hurricanes, wildfires and widespread droughts).
Climate restoration is the principle of removing CO2 to get back to pre-Industrial Revolution levels, specifically below 300 parts per million (ppm), and restoring the world's ecosystems, such as increasing ice in the Arctic. In spite of the IPCC warning, governments and mainstream nongovernmental organizations have not targeted climate restoration in any meaningful way to date. [5 Ways Climate Change Will Affect Your Health]
In line with the IPCC report, the GND set several 10-year targets that include keeping global temperatures less than 2.7 degrees Fahrenheit (1.5 degrees Celsius) above pre-industrial levels, meeting 100% of the country's energy needs through renewable and zero-emissions energy sources, and reducing greenhouse gas emissions to net zero by 2050. But the proposal also exceeds those goals by specifically calling for the removal of CO2 from the atmosphere and restoring natural ecosystems.
It's promising that the GND includes the removal of some atmospheric CO2, but the resolution stopped short of setting a specific target. That's a mistake. In order to restore a healthy climate, society should set a goal of reducing CO2 to levels less than 300 ppm by 2050. That means removing roughly a trillion tons of CO2 from the atmosphere (depending on how quickly emissions of the gas are reduced); a feasible goal, but one that will only be met if governments, scientists and private enterprise join forces.
A number of companies have developed the capacity to remove small amounts of atmospheric CO2 from power plants; a few are in the early stages of using technology to remove CO2 from the air. At scale, these machines will be able to remove massive amounts of CO2 from the Earth's atmosphere. A bipartisan-sponsored tax incentive for CO2 removal was included in last year's budget; the same group of lawmakers have proposed new legislation this year to promote further research and development of the technology.
Turning back the climate clock
Removing atmospheric CO2 is critical because we are currently at a level not seen since before humans evolved. For about 800,000 years, until the Industrial Revolution, global CO2 levels were, on average, 280 ppm. That's the level at which our species and civilization evolved, and the optimal level needed to cement a healthy future for our planet. That level of CO2 should also be the stated goal of the GND.
Scientists have long agreed that the highest level that might possibly be safe for humans is 350 ppm, which we exceeded in 1988. We passed 400 parts per million (ppm) in 2016 for the first time in millions of years. We are now at 410 ppm (March 2019), and at the current rate of growth, we could reach 500 ppm within 50 years. (To put these numbers in context, consider that our current CO2 increase rate is more than 100 times faster than the rise that occurred when the last ice age ended.)
With higher concentrations of CO2 come higher temperatures; it is impossible to keep global temperatures from rising without removing some CO2 from the atmosphere. The question is, how do we remove the CO2, where is it going to go and — most critically — who is going to pay for it? [8 Ways Global Warming Is Already Changing the World]
Climate restoration meets capitalism
There are two primary categories of CO2 removal methods.
The first is using technology to capture CO2 — directly from the air or from the exhaust from power plants (called flue gas) — and either pump it underground or turn it into products.
Companies tackling this challenge have developed technologies that can take CO2 directly from the air, and they're improving in efficiency every year. In order to finance the removal of CO2, they usually convert it into commercial products, although, with one exception, they don't have markets large enough to finance the removal of significant amounts of CO2. Moreover, when these companies insert captured CO2 into products such as fizzy drinks, enhanced oil recovery (EOR), and green fuels, the CO2 is released back into the atmosphere. To make a real impact on the climate, we must permanently sequester the carbon.
The second category of removal involves natural strategies, such as leveraging photosynthesis in the oceans and on land. Forests in the U.S. already store and sequester carbon, but at a rate of 3 metric tons of carbon for every acre per year, this process is a drop in the bucket.
Similarly, certain crops grown for human consumption (such as grasses and grains) sequester carbon in their roots. The advantage of these methods is that they are relatively inexpensive; the obvious downsides are that the roots rot over a few years — we are already fighting global deforestation — and there is simply not enough available (unused) land to grow the number of plants needed to sequester and store carbon at the requisite level.
Marine plants such as kelp, eelgrass and other sea vegetation naturally sequester carbon by sinking to the depths of the ocean, where the gas stays sequestered for hundreds to millions of years. Per acre, marine plants can remove up to 20 times more CO2 from the atmosphere than forests can on the land. Yet, like much of our marine life, flora in our seas is disappearing. Rising temperatures are decreasing seaweed communities and fish populations; productivity at some fisheries has been reduced by 15% to 35% over the past eight decades, a trend likely to accelerate as the oceans continue to warm. Technologists and entrepreneurs are working on ways to harness this natural process in order to absorb more CO2 and slow ocean acidification.
Having the technology to remove CO2 from the atmosphere and sequester it safely underground or underwater is only one side of the equation. The critical part is finding paying customers for the byproducts of CO2 removal. [Top 10 Ways to Destroy Earth]
The need for public and private investment
We currently have two existing markets in which to sell carbon from the atmosphere at the needed scale: seafood and rocks for construction.
The first is a bit speculative, first discussed by John Martin in 1988. Sales of fish and seaweed — byproducts of restored ocean photosynthesis — can pay for ocean restoration. Experts say that restoring about 1% of the ocean would be sufficient to remove all of the excess CO2 in our atmosphere by mid-century, while being paid for by the profits or taxes on fish and seaweed. One method, Marine Permaculture Arrays, currently being funded, in part by the Grantham Foundation, restores ocean health and grows seaweed by upwelling nutrient-rich deep seawater. Martin's method of using minute amounts of powdered iron ore to restore depleted fisheries was politically controversial in 2012, but is now making a comeback. The methods to ensure that large amounts of CO2 are sequestered safely by these processes are being perfected; research funding, either public or private, would accelerate this development and bring us climate restoration sooner.
Although oceans store a tremendous amount of carbon, carbonate rocks such as limestone store even more. Carbon dioxide from the air or from power plant exhaust can be mineralized above ground and sold. The gas can also be pumped underground into basalt rock, which actually converts the dangerous stuff into solid limestone (calcite minerals) in just a matter of months. Climeworks, the world's first commercial Direct Air Capture (DAC) plant, is doing precisely this sort of geological storage — which the company calls a "permanent solution."
Climeworks estimates the cost at scale to be $100 per ton of CO2; removing a trillion tons of CO2 this way could cost $100 trillion over 30 years. This solution is only feasible if governments pay for it; to put that in perspective, in 2017, global military spending was $1.7 trillion.
Aside from seafood, the market with the most potential to reach our CO2 removal goal is rocks used in construction. With the exception of water, aggregate is the most transported material on Earth. Consider the fact that, globally, we buy 50 billion tons of aggregates each year for use in concrete, asphalt, road base and buildings worldwide. Of this, 70% is limestone, a rock that is almost half CO2 by weight.
Therefore, synthetically converting CO2 to limestone makes sense from an economic standpoint, and is being done now. If suppliers shifted from quarried rock to synthetic limestone made from atmospheric CO2, we could remove and sell all the excess CO2 from the atmosphere by 2050. [Top 10 Craziest Environmental Ideas]
Scaling this up by 2030 might require $5 billion in corporate investment, but the benefit is that this solution supports itself, negating the need for government subsidies or additional taxes. (One company working on this is Blue Planet, in which the author is an investor.) The limestone is created locally where it's used, so it becomes more cost-efficient than quarried rock by reducing high transportation costs. Synthetic limestone is cost competitive when the quarry is more than 50 miles (80 kilometers) from the user. In large cities, the material must often be shipped from quarries hundreds of miles away. Blue Planet's synthetic limestone was recently used in the construction of San Francisco International Airport's Terminal 1 extension.
No time to waste
Foundations, activists and policymakers — including those who introduced the Green New Deal and those sponsoring legislation to promote carbon capture technologies — understand that removing atmospheric CO2 must be part of the solution in tackling climate change. It's a good first step.
Now it's time to move the needle and set a goal of getting CO2 levels back below 300 ppm by 2050. Removing a trillion tons of CO2 is a gargantuan task, and it's estimated to cost $100 trillion if governments buy the carbon, or a few hundred billion dollars if done wisely, utilizing existing commercial markets. Those numbers are almost incomprehensible, but that doesn't mean the task is impossible. We have the technology and we have the markets for the byproduct. Now we need a wholesale effort from the private sector to scale both. Let's get to work.
Peter Fiekowsky is the founder and president of Healthy Climate Alliance, a nonprofit education, networking and advocacy program of the Foundation for Climate Restoration, with the goal of restoring the climate. HCA serves as a bridge between the public, policymakers and technical and business experts. Fiekowsky is also a board member of Zynergy Capital and an MIT physicist; he contributed this article to Live Science's Expert Voices: Op-Ed & Insights.