The aim of climate restoration is to restore a safe climate for humanity and current ecosystems. In the last post, we saw how our outdated climate goals interfere with the effort to reduce CO2 to safe levels and thus restore the climate.
Now let’s consider: What is a safe climate?
“Historically safe” vs “theoretically safe”
If you put your children on a flight, wouldn’t you insist they travel on a plane that’s been proven to be safe? Let’s say a pilot tells you, “We have a newer plane that our computer models say is theoretically safe, so you should book that one.” Would you risk your kids on an aircraft that hasn’t proven safe in practice? Shouldn’t the same caution apply to spaceship Earth?
In 800,000 years, CO2 never rose above 300 ppm
We evolved with these levels, so we know they’re safe for us and future generations (Figure 1). They’re historically safe—based on the fact that humanity survived and thrived with them over the long term. We know this from ice cores—physical reality—not from computer modeling or someone’s theory. That’s why below 300 ppm is the goal of climate restoration.
We passed 300 ppm a century ago. Today CO2 is at 420. If we achieve only net zero by 2050, it will be 450 ppm—50 percent higher than is proven safe.
Figure 1. 800,000 years of CO2 levels. Adapted from NASA.
The last time CO2 levels exceeded 300 ppm, homo sapiens did not exist. Today CO2 is 40% higher than 300 ppm. Achieving net-zero by 2050—without significant CO2 removal—would raise CO2 levels higher still.
Each time CO2 started creeping toward 300, Nature pulled it back down. (Only once did it actually reach 300 ppm before a century ago.) The dips indicate ice ages, brought on by natural CO2 removal of roughly the amount of CO2 we need to remove now.
We’ve understood this natural mechanism for over 30 years and can do the same, within decades.
Why do we say we CAN restore CO2 below 300 ppm?
Nature regularly removes the amount of CO2 that would return us to a safe climate (roughly a trillion tons). She has done so about 10 times within the last million years, cooling the Earth before ice ages (Figure 1). And no, we wouldn’t head into an ice age: We’re starting from a much higher temperature baseline today.
What’s her secret? Boosting photosynthesis in the ocean, which covers most of the planet. The mechanism is intriguing and will feature in future posts. Suffice it to say that when CO2 approaches that 300 ppm limit, dust storms increase, propelling minerals, particularly iron, over the ocean. In iron-starved areas of the ocean—and there are many—a miniscule dose stimulates phytoplankton to photosynthesize luxuriantly, drawing in significant quantities of CO2. Phytoplankton also forms the base of the marine food chain, so it regenerates life in those areas. As the plankton and whatever eats it die, the biocarbon sinks to the ocean depths. Nature is clearly adapted to the approach, so we consider it historically safe.
Nature has done it. We can, too.
In the 1980s and ‘90s, in a striking demonstration of biomimicry, scientists figured out how to replicate iron-rich dust storms. The process has been demonstrated on a small scale a dozen times, with positive results when applied in the right areas. Our research shows that intentionally treating anemia in a very small fraction of the ocean has the potential to swiftly and inexpensively restore the climate by 2050.
Ice ages occur over thousands of years. More recently, Nature gifted us a year of net-zero—stable CO2 levels—after the 1991 eruption of Mt. Pinatubo. In other words, after Pinatubo spewed minerals into the air, all human-caused CO2 emissions (about 20 gigatons) were zeroed out for about a year.
Our research on the “Pinatubo pause,” indicates that mineral dust from the eruption stimulated ocean photosynthesis and removed CO2 at the speed we need to restore the climate. Replicating the “Pinatubo pause” is an urgent priority, so we can optimize the location, timing, and materials.
The cost of climate restoration? You may be surprised
Distributing small amounts of iron dust is low-tech and the materials low-cost, so funding could be covered by philanthropists and private investors—once society agrees to restore the climate. Ocean iron fertilization costs a couple of cents to pull down a ton of CO2—compared with $600 - $1000 a ton for direct air capture! We estimate that it would take less than $2 billion a year to restore the climate…compared with a $93 billion bill for climate-related disasters in the United States in 2023 alone.
Why don’t more people know about this?
The ice-age data has been available for 30 years. People constantly ask me, Why aren’t climate activists clamoring to put Nature’s approach into action?
I suggest that the answer lies in the global community’s adhering to the outdated language of the UN goals, rather than its spirit, which was undoubtedly to keep humanity safe. For decades, the “geoengineering” label adhered to attempts to restore a safe climate, discouraging both public and private funding.
We urgently need to resolve the ethical dilemma
We need to update our collective climate goals to call for a safe climate. The United Nations could spur great progress by adding two words to its current goal to “stabilize greenhouse gas levels.” “Restore and stabilize...” could literally make a world of difference. (Any good editor would drop the rest of the sentence, about “interference,” since it’s ambiguous and confusing.)
In the meantime, a global leader such as the President of the United States could unilaterally declare a national commitment to restoring a historically safe climate for the benefit of current and future generations. Declaring a commitment to climate restoration is likely to set in motion the public and private initiatives needed to get it done, much like with the 1960s moonshot.
An idea whose time has come
The movement to restore a safe climate is picking up speed. In July 2023, the California Senate unanimously passed a resolution that commits California to restoring a safe climate. A similar resolution is being considered for introduction into the House and Senate.
In February 2024, both the Massachusetts Institute of Technology (MIT) and the Bezos Earth Fund promoted climate-restoration goals. These are the first major organizations to step up to lead us out of the climate stalemate in which we’ve found ourselves for 40 years.
MIT introduced their new Climate Project February 8; it includes a mission to “restore the atmosphere.” Similarly, the newest Bezos Earth Fund Prize centers on “returning greenhouse gas concentrations to pre-industrial levels.”
In the civil-society sector, the Grandparents Fund for Climate Restoration (GCR.fund) has launched a crowd-funding campaign to demonstrate a wide popular demand for climate restoration as well as fund climate restoration projects.
What can citizens and groups do?
Raise our voice! Let key leaders—legislators and especially the U.S. President come to mind—know that we want to restore a safe climate by 2050. Request they make a commitment to do so. Remember that they have a rut 40 years deep to climb out of, so be patient.
We can also ask state legislators and members of Congress to introduce or cosponsor a congressional resolution for climate restoration.
Concerned citizens can request leaders of NGOs and universities to commit their own organizations to climate restoration.
A symposium held at a major university could bring influential groups together—youth and media groups, prominent universities, philanthropists, environmental NGOs, government agencies, faith leaders…
Without leaving your chair, you can:
Plus: Learn more. Request a presentation to your organization. Donate. Join the Foundation for Climate Restoration. Volunteer.
If I understand correctly, the proposed process has occurred naturally at fractions of the rates of deposit needed to remove the legacy carbon load. So while we know the oceans and sea-based food chains are not majorly disrupted at those rates, we do not know how the rates being proposed here would affect these things. Oceans are already teetering on the edge of their ability to support familiar lifeforms due to increased temperature, acidification, reduction in freshwater breeding grounds and saltwater marshes, and over fishing (perhaps not exhaustive). So what do we know about the overall oceanic ecosystem and its ability to thrive under the proposed treatment rather than suffer major collapse?
Because major interventions like that being proposed could have high impact unanticipated side effects, it would probably be wise to have a stable of solutions applied at lower levels of intensity in case one or more turn out to be infeasible or have intolerable side effects.
It seems to me that geoengineering is a bogey man here! People, me sometimes, are afraid to mess with Mother Nature. Obviously we have massively played with her in very destructive ways. How can you assure the scientists giving counsel to President Biden that this science is good enough for now, and safe enough to try? After all, we are running out of time.