There’s a great deal of doom and gloom about the environment everywhere you look though it’s far from certain we’re all going to hell in a handbasket. The assumption underlying the negative sentiment, which never gets discussed, is that we can’t possibly live without burning carbon and making carbon dioxide and, even if we switch to renewables, the carbon already there more or less dooms us.
Nothing could be further from the truth though curbing emissions, which seems to be the meme associated with climate change, won’t be enough for multiple reasons. But we can switch to renewables and we’ll need to reabsorb some carbon and it can all be done with a little common sense.
An overlooked reality central to the discussion is that all of the carbon we’re releasing into the air today was once there, many millions of years ago. In other words, we are coming full circle in a very long carbon cycle.
The carbon cycle
First, plants originally took carbon out of the air and when they died they were fossilized and turned into the fuels we use today. For instance, we know that coal is made from buried and highly compressed wood. Over millions of years a marsh will be filled in by many generations of trees, grasses, and other plants that live, die, and fall. Some of those plants don’t decay though; instead they sink below the water where there is little oxygen and few organisms to rot them. Over time compression happens due to siltation and tectonic shifts and the woody materials turn first to peat and then to coal.
A similar process makes petroleum. Today’s oil fields were once shallow bodies of water where invertebrate life teemed and died and when they expired those little invertebrate bodies underwent a process similar to how coal is made. The largest oil field perhaps in the world, Ghawar, in Saudi Arabia was formed from a giant worm colony on a shallow reef that existed for millions of years. The Permian Basin in West Texas is named after a shallow sea (the basin) and a geological period, the Permian, which lasted roughly between 250 million years ago and 300 million years ago. We began pumping oil in West Texas in the early part of the 20thcentury and although we still extract oil there, it’s running out.
As you can see, it takes millions of years to make fossil fuels by natural methods. So the second point is the fossil fuels found in the earth’s crust are available in large but limited quantity and they’re running out. We started pumping oil in the US in 1859 in Titusville, PA. Oil exploration started in the same era in other parts of the world too, for instance the Black Sea basin. So, the assumption that we’ll be able to use fossil fuels indefinitely is wildly optimistic. The 2014 BP Annual Report stated that the earth has a 53-year supply of oil remaining in the ground (proven reserves) if extracted at current rates. That’s 1.688 trillion barrels of crude — certainly a lot, but is it enough? The BP report also said,
“Nobody knows or can know how much oil exists under the earth’s surface or how much it will be possible to produce in the future.”
Which is a little ingenuous because for all our efforts we haven’t found any new oil deposits since 2003. Since the 1980’s we’ve used oil at a rate four times faster than we’ve found it. Appraisals vary but a conservative estimate is that we’ve used about 2.3 trillion barrels of the stuff. We use more each year, too. In 1859 we only used half a million barrels in the US and today we use nearly 20 million barrels per day.
There’s more too. A 2013 article in The Guardianstates,
“Official data from the International Energy Agency (IEA), US Energy Information Administration (EIA), International Monetary Fund (IMF), among other sources, showed that conventional oil [production] had most likely peaked around 2008.”
The article quotes Dr. Richard G. Miller, who worked for BP from 1985 until retiring in 2008, saying,
“We need new production equal to a new Saudi Arabia every 3 to 4 years to maintain and grow supply. . . .New discoveries have not matched consumption since 1986. We are drawing down on our reserves, even though reserves are apparently climbing every year. Reserves are growing due to better technology in old fields, raising the amount we can recover — but production is still falling at 4.1% p.a. [per annum].”
Summary so far
This piece is supposed to be about the environment but what precedes is necessary background. All of this is to say that fossil fuels are available in limited quantities and they’re running out. That’s in addition to the reality that when we burn them they cause pollution that causes global warming. So there are really two reasons to care about climate change or global warming and both point to the need for new energy sources. If you don’t believe the climate change science, at least consider what happens if fossil fuels run out and we’ve done nothing to prepare.
Carbon and climate
Other articles I’ve written deal with alternative energy and the many sources of abundant energy we can access, and the list of sources only starts with wind and solar. The rest of this piece focuses on the problem of what to do about all the carbon in the atmosphere.
Estimates vary but according to the U.S. Energy Information Administration (EIA), there are between 5 and 6 trillion tons of greenhouse gasses or GHGs in the atmosphere,most of them carbon dioxide. It’s difficult to get an exact number because until recently it has been increasing and concentration fluctuates with the northern hemisphere’s growing season.Lately, with the replacement of some coal-fired power generation and other efficiencies, the rise in the quantity of CO2in the air has slowed, however we’re still pumping between 35 and 45 gigatons of CO2into the air each year.
Now, if we could remove 1 trillion of those tons of CO2from the environment, it would bring us back to levels last seen in the 1990s. That’s still a lot but the climate back then was better than it is today. No matter, aiming at that decade is just for doing easy math. With the right carbon capture solutions, we could go as far back as we want though going back too far could easily trigger another ice age and no one wants that.
The question becomes how? How do we remove 1 trillion tons of CO2from the air and keep it out? Nature did that and then some back in the Permian period. Could it still do that trick? The short answer is yes, but a more nuanced answer is that we also don’t have millions of years to complete the process.
When we invoke nature as a solution, we’re talking about green plants that use solar energy to capture CO2and turn it into long chains of hydrocarbons that stay out of the air. On today’s earth humans use much of the land mass for agriculture and we can’t double dip; we can’t use the same land for food production and for growing things that capture carbon for sequestering. There’s also the issue of water and where all the fresh water would come from to nourish those crops.
Some have suggested using mechanical methods to take carbon out of the air and sequester it under ground but there are serious limitations to this approach. First there’s an energy issue. Most schemes use electricity to capture and compress CO2,but they don’t account for that energy. It has to come from somewhere and if it comes from conventional sources, we’d be burning carbon to make electricity to capture carbon.
Sadly, only about 20 percent of the energy in fossil fuels used for electricity generation actually gets turned into electricity available for consumption. The majority of the energy goes up a smokestack or is lost in the transmission process. You could use renewables to power the CO2absorption process but the energy cost and the electric bill would be very high. Under those conditions, it would be better to do nothing.
Then there’s the problem of leakage. Advocates for a mechanical approach say we could store compressed CO2in old oil wells. Unfortunately, oil wells are situated in porous rock and the gas could easily leak out. Watch a few videos of burning plumbing fixtures in homes situated near gas fields and you see. CO2won’t burn but if it fills up your home it could kill you. So for a lot of reasons, mechanical capture and sequestration don’t offer a realistic solution.
Back to the Permian
All that brings us back to photosynthesis if we can find ways to grow green plants without using farmland and if we can find a cheap and readily available energy source. All this is possible in the ocean. Marine scientists have already run experiments and proven the viability of capturing carbon in the world’s seas, here’s how it works.
All life in the ocean depends on photosynthesis. Big fish eat smaller fish and the smallest fish eat phytoplankton. Phytoplankton is a class of microscopic green plants and it is distinguished from little animals of the same size called zooplankton.
In the 20thcentury, marine scientists discovered that there was little life in the middle of the ocean primarily because there was very little photosynthetic activity. Lack of photosynthesis comes down to the sea water lacking a key element for life, iron. When scientists fertilized seawater with dilute iron solutions, phytoplankton readily bloomed. The scientists discovered that phytoplankton could capture the equivalent of a redwood forest’s worth of CO2in a very short time.
Of course, phytoplankton provide an important food source, remember all those littlest fish. It turns out that most of the phytoplankton may be readily eaten, but about 20 percent of them manage to live life and die of old age at which point they sink to great depths. That’s the beginning of the petroleum cycle.
The point of solving climate change or at least abetting its worst effects doesn’t have to be strictly removing carbon from the air. Instead, think of it as changing carbon dioxide into substances that have different chemical characteristics from CO2so that the carbon is not toxic to the environment. This is part of the carbon cycle and photosynthesis does this through green plants turning CO2into sugars and the materials of life. Photosynthesis imports CO2into the living part of the carbon cycle thus reducing atmospheric carbon and its climate changing effects.
If some phytoplankton get eaten, it’s no big deal. It will enter the food chain and some of it will eventually become part of commercially viable fish species that land on a dinner plate. Some of that carbon will sink, as we’ve seen, and some of it will return to the air. But with a program of fertilizing the ocean we can achieve a steady state where there’s always a sufficient amount of that carbon in living things and not the air to help improve climate.
Dimensions of the challenge
Earth is bathed in solar energy and each year green plants, including food crops, grasses, trees, mosses, and tiny sea creatures like algae and phytoplankton, capture solar energy at an annual rate estimated at 130 terawatts, which equals more than 6 times the power consumed by human civilization. Green plants turn this solar energy into biomass equal to between 100 and 115 billion tons, not all of it is food.
What if we could double the amount of photosynthesis happening on the planet? We could do it in the ocean where there isn’t a lot of life but where sunlight is abundant and the nutrients, except for sufficient iron, are plentiful. There’s a lot more ocean than land and it’s not being used for much at the moment. If we could implement an iron fertilization scheme, we could remove 1 trillion tons of carbon from the environment in short order.
Iron fertilization is a natural process. Winds carry dust containing minerals like iron to the oceans which helps fertilize the waters closest to shores. Actively fertilizing the ocean with iron is a safe and low-cost approach to a though problem.
Of course there is a caveat. There always is. Since we’re dealing with the carbon cycle in which only some carbon gets sequestered while some is re-released to the air and some makes it into the food chain, we would have to keep this process going for some time. How long is hard to say but iron fertilization isn’t hard to do and it’s cheap. We’d also come to depend on all the sea food.
That’s actually a good thing because this process is hard to overdo. By that I mean, over-capturing carbon could lead to a new ice age or reduced plant production. But with so many feedback loops over-doing it would be hard to do and there are plenty of ways to monitor progress.
We’re at a point where we have to both reduce our emissions and reduce the amount of carbon in the environment. I address the emissions problem elsewhere but note that we’re going to be dependent on burning carbon for a long time, just consider flying machines and all the materials we make from fossil fuels like rubber, plastics, and even steel. It’s unlikely we’ll ever be free of carbon but can do much to not burn it and to reabsorb what we do burn. So carbon absorption through the carbon cycle and ocean fertilization is a needed approach to juggling our carbon load.