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Climate change is happening and whether we declare this a climate emergency or climate crisis the fact remains, something needs to be done about it, fast.
The UN recently warned that global warming is not only having a direct impact on the environments we live in but will also have a detrimental effect on human rights across the globe. Furthermore, NASA reports that human activity continues to inflame the current crisis with more carbon dioxide in our atmosphere than all of human history.
This urgent call for concern has world governments, private initiatives, individuals and other organizations seeking solutions that will alleviate the stress human activity puts on the planet. Thus, the hope is to combat climate change by reducing the current impact humanity has in the immediate future. One such enterprise is known as ‘solar geoengineering’ which works toward reflecting incoming sunlight back into space, in theory this would slow a global temperature rise.
Whilst the term ‘solar geoengineering’ sounds like a perplexing sub-plot of a Hollywood disaster movie it does in fact have prestigious endorsement with Bill Gates currently championing this radical project. So, what does it entail? Solar geoengineering has many different forms, from removing certain clouds to sending giant mirrors into space, the latest scenario involves mimicking the effects of a giant volcanic eruption.
Can solar geoengineering limit rainfall extremes?
Andy Parker, project director at the Solar Radiation Management Governance Initiative, told CNBC, “Modeling studies have found that it could reduce the intensity of heatwaves, for instance, apparently it could reduce the rate of sea-level rise. It could reduce the intensity of tropical storms.”
The theory is that by flying a fleet of planes at high altitudes, spraying millions of tons of particles would create a giant chemical cloud capable of reflecting the sun’s light and thereby cooling the Earth’s surface. This is similar to what happens when an ash cloud is sent high into the atmosphere during a volcanic eruption as Sulphur dioxide combines with water to form sulfuric acid aerosols that reflect the sunlight – generating a cooling effect.
However, there are causes for concern as research has suggested that, if solar geoengineering was implemented to fully offset global warming, rainfall could decrease. This would have a direct impact on the water supply with some regions feeling the effects much worse than others. Therefore, a more moderate intervention would be encouraged with a scenario that imagines solar geoengineering being used to offset half of the warming caused by rising CO2 levels. Furthermore, other potential consequences include an impact on localized weather patterns as well as prolonged spells of grey skies and diminished sunlight.
Yet, one of the benefits of this technology is that the process is affordable, and the alternatives could be much worse if the current crisis continues to spiral out of control. Stephen Gardiner, author of “A Perfect Moral Storm: The Ethical Tragedy of Climate Change shared his opinions about the technology stating, “These consequences might be horrific. They might involve things like mass famine, mass flooding, drought of kinds that will affect very large populations.”
A new study recently published in Nature Climate Change, casts its gaze on a scenario that utilizes the process ‘stratospheric aerosol injection’. The study led by Dr. Pete Irvine, a postdoctoral fellow at Harvard University, states, “We have a case where CO2 concentrations have doubled, and we turn the sundown by 1%. This is a kind of sketch of how halving warming with solar geoengineering would influence the climate.”
Then by focusing part of their research onto the issue of rainfall the team was able to devise an argument that suggests because of the overall cooling effect the reduced temperatures would counterbalance the reduced rainfall due to a decline in water evaporation.
Co-author of the paper, Professor David Keith, leader of the solar geoengineering program at Harvard University, said, “While it seems reasonable to assume that less rain means that things are drier, in fact, what matters more for ecosystems and farmers is water availability: rainfall minus evaporation. Geoengineering reduces rainfall, but it also reduces evaporation by reducing temperatures. So, a decrease in rainfall can be associated with an increase in water availability.”
These findings challenge previous assumptions that some regions would be worse off than others with moderate application of solar geoengineering being effective in the fight against a changing climate. However, this technology is not a total solution for the reversal of climate change, nor does it solve the issues surrounding the rate in which greenhouse gasses are pumped into the atmosphere.
With some scientists believing it still to be a contentious issue as it fails to address the root causes of global warming. Yet, what is does offer is the hope that there is a technology that could assist the requisite collaborative effort in addressing the current climate crisis. Solar geoengineering at least adds another string to the bow of resources necessary in the fight against climate change.