Scientists look to block out the sun to combat global warming
Scientists at Harvard University are attempting to combat global warming and cool the planet by releasing chemicals into the stratosphere. While that may not sound like the smartest idea, the research team is on the cusp of conducting the first real-world experiment for this long-assumed outside chance of saving the planet.
The process, known as “geoengineering”, the Harvard team wish to replicate is similar to the effects on global temperature observed after volcanic eruptions. Scientists in the ‘90s noticed that after a volcanic eruption the planet’s temperature would drop. The sulphur released would spread across the globe and create a temporary protective shield from the sun’s rays.
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After the Mount Pinatubo eruption in 1991 scientists noticed that the Earth cooled by 0.5C. Post-eruption, for over a year, earth’s temperature matched levels from before the invention of the steam engine.
Excluding chance volcanic eruptions, scientists have had little empirical data to go off of, relying mainly on computer simulations. Now, the Stratospheric Controlled Perturbation Experiment (SCoPEx) team aim to replicate these effects. The SCoPEx team aim to achieve this with the introduction of calcium carbonate, a compound found in everyday materials from paper to cement.
The team plans to send a balloon 20km high, allowing it to release 100g plumes of calcium carbonate. The commonplace compound doesn’t have the same power as sulphur dioxide, but it should still deliver a blocking effect. Importantly, 100g won’t alter global temperatures but allows the team to study how it interacts with our atmosphere. Thereafter, further experiments can be reviewed in an effort to make geoengineering work on a larger scale.
Geoengineering has brought up significant debate since conception, and you could understand why – messing with the sky is a pretty big deal. The main critics believe it’s too uncharted and the risks too high. For instance, if taken too far we could damage crop growth.
Such issues are felt by the Harvard team, which is why they’ve set up an external advisory committee to review the project. Speaking on the matter, Peter Frumhoff, chief climate scientist at the Union of Concerned Scientists, says “getting it done right is far more important than getting it done quickly.”
Other critics note that, due to its temporary success, geoengineering encourages complacent behaviour from humanity. They highlight that blocking the sun’s rays is far from solving the problem.
“This is as much an experiment in changing social norms… as it is a science experiment,” claims Jim Thomas, co-executive director of the ETC group, an environmental advocacy organisation. Counter arguments point to research that suggest we’re too far gone to be ignoring geoengineering.
It seems that advocates of geoengineering believe the time for criticising a get out of jail free card appears to be coming to an end. With the SCoPEx team hoping to launch in either spring or autumn 2019, they may be right. Arguably, if the research is conducted properly, having that card up humanity’s sleeve mightn’t be the worst of things.