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Communities relying on beach restoration to fend off erosion due to rising sea levels are facing a crisis. The globe is facing a shortage of sand, The Economist has reported.

After water, sand is the second-most consumed resource globally. With projections that the world will have 43 megacities with more than 10 million inhabitants by 2030, demand for sand to build roads as well as make concrete and glass and other accoutrements of urban life has risen inexorably as the world rapidly urbanizes.

Sand seems like a low-tech solution in a world increasingly likely to look to technology to address climate change. That is the message that came out of a March meeting in Nairobi that considered a proposal to have the U.N. Environmental Programme study geoengineering to combat climate change. The proposal was killed due to opposition by the United States and Saudi Arabia with backing from the hydrocarbons industry.

Pricing carbon emissions and electrification of energy are the two most direct paths to decarbonization. But carbon pricing and electrification may not be enough to forestall overshoot – a 1.5-degree Celsius rise in global average temperature above pre-industrial levels at which point climate change’s most catastrophic disruptions would be triggered.

Hence, there is rising interest in geoengineering.

Geoengineering is an umbrella term that involves manipulating the Earth’s natural processes to attenuate either the build-up of atmospheric carbon dioxide or its effects. The proposal rejected in March would have had the U.N. Environmental Programme study two approaches: carbon dioxide removal (CDR) and solar radiation management (SRM).

The most technologically mature CDR process is bioenergy with carbon capture and storage (BECCS). It involves burning biomass to generate electricity and scrubbing the resulting emissions to separate carbon and store it underground in large geological formations that can contain the gas for at least a long time if not for eternity. Burning biomass and capturing and storing the emissions produces negative carbon dioxide emissions because the feedstock is sourced from wood and other materials derived from plants that absorb carbon dioxide (Unlike coal-carbon capture and storage, since coal doesn’t absorb carbon dioxide).

BECCS has been tested and works. It’s also expensive, energy intensive, and practical mainly in areas where there are proximal geologic structures to store the carbon. Scaling up BECCS to deal with overshoot on a global level would take time, and it’s unclear if enough land is available to grow enough biomass to enable BWCCS to make a difference.

SRM solutions are based on conceptual models and have yet to be tested in practice. One approach called stratospheric aerosol injection (SAI) would seek to cool the earth’s surface by pumping gases into the stratosphere to reflect some of the sun’s heat. Simulations suggest it could be effective; however, it would be difficult to scale to global proportions, and doing it in just one country could trigger catastrophic weather events in another.

Another SRM approach, marine cloud brightening (MCB), would involve spraying sea salt into marine clouds to reflect sunlight. Simulations suggest it would work at a regional level, although with the potential for disruptions (albeit more localized than those associated with SAI). A third approach would use chemicals for cirrus cloud thinning (CCT), reducing the clouds’ heat trapping effect and allowing more long-wave radiation to escape into space, cooling the earth’s surface.

The practicability of geoengineering to remediate climate overshoot remains to be determined. Less uncertain are the catastrophic consequences that failure to effectively tackle climate change portends. Such events are of the sort of floods, hurricanes and wildfires we’ve seen over the past two years in Puerto Rico, North Carolina, California, Nebraska and throughout the Midwest, and along the Gulf Coast. According to the National Oceanic and Atmospheric Administration – NOAA – the cost of these extreme weather events exceeds $150 billion, not counting the costs of Midwest flooding, yet to be totaled.

A recent CBS poll showed the American people to be awakening to the need to act on climate change. In that poll, 62 percent of people agreed climate change is due to human activity and 79 percent agreed that impacts are serious now or will be in the future. And 59 percent said yes, humanity can do something to stop climate change.

This message has not gotten through to the powers that be in Washington who in March shot down the proposal to study geoengineering. At this point, the stakes are too high to not at least investigate whether geoengineering can be harnessed to help remediate climate overshoot. This message needs to be driven home.

Matt Slavin founded M.I. Slavin to provide consulting in project management, strategic planning, research and communications. Contact him at 503-619-5601 or [email protected].