Solar geo-engineering as an effective coolant

It is an interesting study that volcanic eruptions caused cooling of temperatures as found in the 1815 eruption of Mount Tambora in Indonesia, and it has reduced temperatures by 3 degrees Celsius or 5.4 degrees Fahrenheit. The conclusions were based on the research of Thailand’s Pornampai Narenpitak at the National Science and Technology Development Agency in Bangkok and Indonesia’s Heri Kuswanto at the Sepuluh Nopember Institute of Technology in Surabaya in Eastern Java. But the two scientists are quite guarded in projecting their conclusions as a way of tackling the climate change issue. The Mount Tambora explosion spewed rock and ash of 150 cubic kilometres or 150,000 gigalitres into the stratosphere, which resulted in the fall in temperatures. The implied experimental solution is that large quantities of sulphur dioxide could be injected into the stratosphere to bring down the temperature based on the computer model of Mount Tambora explosion, and the technology is called solar geoengineering (SRM). But it is an untested solution. Narenpitak is very cautious about the effectiveness of solar geoengineering. He says, “There’s a lot we do not understand about the climate system itself, let alone SRM.” Kuswanto’s team found that SRM produced positive results in some parts of the country as the temperatures cooled, while the temperatures rose in other parts. Kuswanto says, “Unfortunately, we haven’t done any more studies about what is the cause of these different results in Indonesia, but of course to improve it, we have to look at the climate systems and we need to study it more.” And Narenpitak argues that there have to be country-specific studies: “And to assess the impacts, I think it’s best to have people who understand the context of each country to do the analysis. We can’t make any informed decisions if we do not know about these things.”

Two things follow from the observations of Narenpitak and Kuswanto. A technological solution like SRM cannot be applied globally because studies show that there are no uniform global impacts. The technologies to bring about fall in temperatures – the United Nations target for containing the tipping point of irreversible climate change is 1.5 degrees Celsius. And tentative technological solutions like SRM cannot be used indiscriminately across the globe. A major lesson is that there cannot be global technological solutions. Secondly, there is need for a more detailed study of climate system to be able to reach out to appropriate solutions. There is a growing awareness that the data-based scientific knowledge about climate change is quite inadequate, something that climate activists and climate warriors do not seem to acknowledge. And the projections being made in the climate change studies are not foolproof and there would be need to revise them as more information is gathered about the climate system. Perhaps there is not one but many climate systems. A climate model has shown that injecting aerosols injected 15 degrees north reduced monsoon rain in the Northern Hemisphere, while it increased rainfall in the Southern Hemisphere, and there was a similar result the other way round as well.

But many climate change experts argue that there is no need to look for outlandish solutions to contain rising temperatures in order to halt climate change. There is the straightforward solutions of mitigation. Says Dhanasree Jayaram, a research fellow at Earth System Governance and assistant professor at the Manipal Academy’s Higher Education’s Centre for Climate Studies in India: “The benefits itself (of SRM) can be questioned in the sense that, do we need this when we have others means like mitigation, which is something we need to push for at this stage.”