As the long-predicted effects of greenhouse gas pollution proliferate, moves are afoot to clean it up.
The modern world is rudely awakening to a situation climate scientists have been forecasting for over four decades. In 1973, British meteorologist John Sawyer predicted atmospheric warming of 0.6C by the year 2000. He wasn’t far off. Observed increases were actually between 0.51C and 0.56°C. In 1981, American researchers led by James Hansen predicted a warming of about 0.65°C by 2017. Warming for that year was actually higher at nearly 0.8°C. In 1989, a special issue of Scientific American ran an article by Stephen H. Schneider entitled The Changing Climate with the subtitle: “Global warming should be unmistakable within a decade or two. Prompt emissions cuts could slow the buildup of heat trapping gases and limit this risky planetwide experiment”.
Thirty years later, the signs are indeed unmistakable: increased frequency and intensity of heat waves, drought and wild fire; regular bouts of extreme weather; glaciers and polar ice caps melting; coastal flooding; rural and suburban homes consumed by forest fires; people dying of heat stroke.
Climate change is bearing down on us because there has been little in the way of the “prompt emissions cuts” recommended by Schneider’s 1989 article. Instead, there has been a massive propagation of our modern, energy-intensive lifestyle turbocharged by a 50 percent increase in world population. Collectively, we are using more land, making more stuff, and burning more coal, oil and gas to fuel the ever-expanding economic machinery. The result is a torrent of anthropogenic greenhouse gases – halocarbons, nitrous oxide, methane, and especially carbon dioxide – pouring into the atmosphere at the rate of over 30 billion tons every year.
If these greenhouse gases were coming from a single source, and were visible (they are insidiously invisible), it would likely be a sight terrible enough to mobilize global action to stop it. But there is no single, awe-inspiring gas fountain to hold the attention of the news media and set the population abuzz. Greenhouse gas pollution is diffuse; it hides in plain sight. Most of it comes from commonplace energy conversion devices around the world that burn fossil fuels: over a billion internal combustion engines in automobiles; tens of thousands of coal, gas and oil-fired steam turbines in electricity generation plants; tens of thousands of turbines and internal combustions engines in aircraft, ships and locomotives; uncounted small internal combustion engines in lawn mowers, chainsaws and hand held tools. We are surrounded by greenhouse gas pollution devices. You likely own one. I do.
Meanwhile, tens of thousands of square kilometers of forests are slashed and burned every year to make room for industrial scale cultivation, urban development and resource extraction. Hundreds of millions of cattle and sheep are happily belching methane as they graze. Thousands of landfills worldwide leak methane.
To make matters worse, recent observations and events underline the feedback effects produced by a warming atmosphere. A recent German study indicates that melting permafrost could allow the release of up to 1 billion tons of methane and 37 billion tons of carbon dioxide by the year 2100. Fires raging in northern boreal forests are producing greenhouse gases at the rate of some 170 tons per hectare. In 2017, 1.2 million hectares of forest burned in British Columbia alone, producing upwards of 200 megatons of greenhouse gas, roughly equivalent to the annual emissions of ten large coal-fired electricity plants.
Most people now understand that this unchecked stream of greenhouse gas pollution is warming the atmosphere. But recent climate research tells us that the warming trend is about to overtake us, if it hasn’t already. In a 2016 paper entitled Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 C global warming could be dangerous, James Hansen and 18 co-authors predict a catastrophic sea level rise of several meters beginning as early as 2066. The scientific team concluded that “the message our climate science delivers to society, policy makers, and the public alike is this: we have a global emergency. Fossil fuel CO2 emissions should be reduced as rapidly as practical.”
However, with the nasty effects of climate change now manifest, the necessity to do more than just “reduce” emissions is obvious. The world economy is clearly not phasing out the old fossil fuel paradigm fast enough. So while we slowly accelerate the phase-in of zero carbon electricity generation plants, battery powered vehicles, and energy efficient buildings in an economy constrained by competitive, cost-conscious interests, we will have no choice but to remove large amounts of CO2 – the major greenhouse gas pollutant – directly from the atmosphere.
Now, the good news: technologies intended to achieve this are in the works.
In Iceland, Reykjavik Energy is developing a carbon sequestration project in partnership with several international research institutions. Called Carbfix, the project captures CO2 from a geothermal electricity generation plant and injects it into basalt rock formations a kilometre or more underground. Once there, it mineralizes into a stable compound within a couple of years. Basalt rock composes about 10% of the planet’s continental surface area and underlies most of the ocean floor. Globally, the mineral uptake of these formations is estimated at between 100 and 250 trillion tons, in theory enough to easily absorb all the excess CO2 in the earth’s atmosphere. So it looks like there’s a way to store the stuff in permanent, solid form.
Along a similar mineralization pathway, a team of researchers based at Trent University, in Ontario, recently devised an experimental process to rapidly and inexpensively capture CO2 by combining it with magnesium to form the mineral magnesite (magnesium carbonate). In nature, magnesite takes hundreds of thousands of years to form. In the lab, it takes 72 days at room temperature, suggesting an uncomplicated route to industrial scale carbon capture. One ton of magnesium carbonate sequesters about a half ton of CO2.
Meanwhile, in Squamish, British Columbia, a Canadian company, Carbon Engineering, is running a pilot project to capture CO2 directly from the air using a chemical solution. The project has been testing a full-scale direct air capture (DAC) unit since 2015, and has shown that CO2 can be removed from the atmosphere for less than $100US per ton. In December 2017, it began combining captured CO2 with electrolysis-derived hydrogen to produce roughly a barrel of carbon neutral fuel per day. Full scale capture plants would each remove up to one million tons of CO2 from the atmosphere annually, and be located according to their purpose. Plants intended for fuel production could be built anywhere; those intended for CO2 sequestration would be built near suitable geological formations. The pilot project in Squamish is funded by private investors including Bill Gates, and by government agencies including Sustainable Development Technologies Canada and the US Department of Energy.
A similar direct air capture facility has been built on a modest commercial scale near Zurich by Climeworks, a Swiss firm. The plant has 18 capture turbines and currently harvests CO2 at a cost of about 600 swiss francs per ton. The venture is heavily subsidized making it possible to sell the CO2 at competitive rates to a nearby greenhouse where it enhances plant growth by 20 percent. Local fizzy drink and bakery companies are interested. The owners expect capture costs to come down as the technology scales up.
In another approach, CO2 can be removed from the atmosphere by breaking it down into its two basic elements. At George Washington University in Ashburn, Virginia, Stuart Licht has been leading a team of researchers on a project called C2CNT, intent on capturing CO2 on a large scale using solar energy. The process uses sunlight to power a molten carbonate electrolyzer that breaks CO2 down into nothing but oxygen and solid carbon nanotubes. Carbon nanotubes are a hi-tech industrial material used to make, among other things, lightweight aircraft bodies and tennis rackets. They are currently produced in an elaborate process and worth up to $300 per gram. The small lab version of C2CNT’s device makes nanofibres directly and relatively inexpensively. Commercial scale versions would be self-powered and constructed en masse in any sunny region on the planet. According to the team’s calculations, the electrolytic process is so efficient that full deployment worldwide could reduce atmospheric CO2 to preindustrial levels in 10 years. Recently, organizers of the NRG COSIA Carbon XPrize awarded Dr. Licht and his team funding to build a full-scale demonstration unit to capture CO2 from industrial flue gas. Direct air capture – and sequestration – would of course be its most useful application.
Not only useful but imperative. A recent report from the Joint Research Centre of the European Union concluded that even with very strong international efforts to curb greenhouse gas pollution, the build-up of atmospheric CO2 will go considerably beyond the limits needed to meet the agreements made in Paris. The report’s authors said that carbon dioxide removal is no longer a choice, but a necessity for limiting warming to 1.5°C.
It would seem that the stage is being set for a global CO2 pollution cleanup effort.