Scientists look to the volcano for climate change solution

With temperatures hitting new records every passing year and 2016 going down as the hottest in history, climate change is increasingly becoming a reality of life.

Many proposals have been put on the table about how to mitigate the effects of the phenomenon, mostly by cutting carbon emissions. But can it be reversed? Some researchers now want another option considered; solar radiation management.

“Solar radiation management is basically a theoretical proposal of reducing the risks of climate change by blocking out some of the sunlight,” says Andy Parker, the project director of the Solar Radiation Management Governance Initiative.

Solar radiation management is built around mimicking the volcano effect. When a powerful eruption occurs, millions of tons of ash and sulphur dioxide are sprayed into the atmosphere, creating a blanket between the earth and the sun.

The sulphur dioxide is then converted into sulphate particles that reflect sunlight back into space, thereby keeping the earth’s surface cool.

In 1991, for instance, Mount Pinatubo in the Philippines produced a powerful eruption that resulted in a global cooling of 0.5 degrees.

So the researchers are proposing that this can be re-created by shooting sulphur dioxide particles directly into the stratosphere to achieve a cooling effect within days.

“It sounds like fiction but it is possible to do it. Volcanoes have proven that it is possible so perhaps it is time for man to try it,” Mr Parker says. 

The concept of solar radiation management was first floated in the 1960s, but research hasn’t gone beyond the lab.

Several reasons have been cited for this, including unwillingness by scientists to divert funding and the general distrust of the technology.

It is only in the last few years that discussions about it have picked up, even though is is still considered a very controversial science.

The African Academy of Sciences is now bringing this conversation to Africa, saying the continent should have a voice in the debate given its vulnerability to the impacts of climate change.

“We as the Africa civil society have been following the solar radiation management conversation since 2015, and we are looking at it as both a threat and an opportunity,” says Sam Ogallah, the coordinator of the Pan African Climate Justice Alliance.

“It is a new technology that has never been tested... We don’t know if it will make our situation worse. At the same time, it is an opportunity because if it works, imagine the things it could do for us. It would mean no more harsh weather, no more severe droughts and floods.”

Under the current carbon emission cuts proposals, each country has pledged how it intends to decarbonise over a certain period, under the Paris Agreement.

Kenya, for example, has an eight-page plan that is pegged on the Climate Change Act to reduce its emissions by 30 per cent by 2030. 

The problem with the decarbonising plan, some scientists argue, is that it will take much longer— decades to be precise — to achieve a global cooling.

Another school of thought holds that while cutting emissions of carbon dioxide (CO2) and other greenhouse gases would slow or halt their rising concentrations in the atmosphere, much of the CO2 released through past emissions will reside in the atmosphere for 100 years or more.

Additionally, inertia in the climate system means that global temperatures will continue to rise.

Granger Morgan and Katharine Ricke of the Department of Engineering and Public Policy at Carnegie Mellon University wrote an opinion piece on the subject, where they argue that solar radiation management (SRM) is the best chance the world has at dealing with climate change, cheaply and quickly.

“Under the current understanding of SRM technologies, the mass of fine particles needed to counteract the radiative effects of a doubling of atmospheric carbon dioxide concentrations is approximately 2.6 million tons per day of aerosol— if injected into marine stratus clouds or 13,000 tons per day of sulphate aerosol if injected into the stratosphere.

By comparison, to achieve the same radiative effect we would need to remove 225 million tons per day of CO2 from the atmosphere for 25 years straight,” the article says.

“For us in Africa, our concern is not the temperature,” says Asfawossen Asarat, an Addis Ababa University professor. “Our concern is the precipitation. What will happen to the moisture? Will there be more rain? Will there be more droughts? These are questions we need answered before we can say whether we support or not. In East Africa we have at least 80 volcanic mountains so maybe we could make use of them in studying this subject further.”

Proponents argue that if adopted, solar radiation geoengineering will be the only known method of rapidly reversing the effects of global warming.

But, given that it hasn’t actually been tested should the world embrace this science? Could the side effects that outweigh the benefits?

“These are actually the most important questions. This is a technology that impacts the complex system that is the climate and nobody knows what will happen as a result. What will be the impact of pumping sulphur dioxide into the air? Will it harm the ozone layer?

There is a possibility of acid rain but the most important question that we need to ask is, how will that impact human health? These are questions that need answers and that means more research,” says Prof Asarat.

With 2017 on course to making a climate record, the world is desperate for a solution. The year 2016 closed the at 1.2 degrees warmer than pre-industrial levels, according to the World Meteorological Organisation (WMO).

Sea levels rose by about 15 mm between November 2014 and February 2016 as a result of the El Niño. This, the WMO says, is well above the post-1993 trend of three to 3.5 mm per year.

The year started with an extreme heat wave in southern Africa, exacerbated by the ongoing drought. Many weather stations reported all-time temperatures, including 42.7°C in Pretoria and 38.9°C in Johannesburg on January 7, 2016.

Record or near-record temperatures occurred in parts of the Middle East and north Africa on a number of occasions in summer.

The year also saw a few weather-related disasters, such as flooding, landslides and hurricanes. East Africa is currently in a drought that started last year, which has greatly affected the region’s food basket.

There are many promising possibilities with solar radiation management, but scientists also urge caution given it is not yet fully understood.