Can geoengineering stop global warming?

This year, a trial is underway to see if using technology to deflect the sun could help cool the planet. Meanwhile, another scientist hopes to spray sulfur dioxide into the stratosphere to reduce global temperatures. These are just some of the innovative attempts taking place to reduce the effects of global warming until further decarbonisation is seen. The question now is whether these delay-oriented geoengineering technologies will have a significant effect on global warming as a medium-term control measure, or whether they pose a major risk to a significant green transition.

Geoengineering refers to deliberate, large-scale interventions in the Earth’s natural systems to counteract climate change or mitigate its effects. These interventions are usually divided into two groups, carbon dioxide removal (CDR) and solar radiation management (SRM). The CDR approach focuses on removing carbon dioxide from the Earth’s atmosphere using technologies such as carbon capture and storage (CCS) and ocean geoengineering, as well as afforestation activities. Meanwhile, the SRM uses technologies to reflect some of the sun’s energy away from Earth, with the goal of lowering Earth’s temperature.

In April, scientists from the University of Washington conducted the first outdoor test of SRM technology in the US The test, in San Francisco Bay, saw a car expel a fine mist of tiny aerosol particles hundreds of meters into the air over the flight deck of a decommissioned aircraft carrier. The goal was to create salt aerosols of the right size in an open-air environment to achieve cloud brightening – changing the composition of clouds over the world’s oceans – to temporarily reduce the temperature on Earth.

This is not the only SRM experiment going on, as many other scientists and institutions are working to delay the impact of global warming until significant decarbonization occurs. David Keith, who leads a climate systems engineering initiative at the University of Chicago, believes it can help reduce Earth’s temperature by using sulfur dioxide. Keith cites the global cooling effects of sulfur dioxide spewed by volcanoes as the impetus for his experiment. In 1991, Mount Pinatubo in the Philippines released 17 million tons of sulfur dioxide into the stratosphere, which reflected sunlight away from Earth. This created a drop in average Northern Hemisphere temperatures of about one degree Fahrenheit over the following year. Keith now believes that a similar reaction can be engineered to help delay global warming.

Unlike the localized experiment in San Francisco Bay, Keith’s approach would not be limited to a specific area, but would be used in the stratosphere, which could influence global temperature. While this could provide an effective means of lowering global temperatures, scientists are unsure of the knock-on effects on weather systems around the globe. Moreover, the sulfur dioxide that is pumped into the stratosphere would eventually fall to the ground, which could cause respiratory problems. David Suzuki, a Canadian environmentalist, suggested“The whole notion of spraying sulfur compounds to reflect sunlight is arrogant and simplistic… There are unintended consequences of powerful technologies like these, and we have no idea what they will be.”

Many scientists are now using geoengineering technologies to reduce the effects of global warming to buy time while governments try to decarbonize their economies. However, there is widespread criticism of the use of SMR technologies due to concerns about artificially altering the Earth’s temperature, as well as discouraging the decarbonization that must eventually occur. Similar criticisms have been seen regarding the use of CCS technologies, which, it is argued, give oil and gas companies an excuse to keep pumping fossil fuels for longer.

However, SMR and CCS technologies receive huge amounts of funding from private companies and governments around the world. The White House pumped billions in various geoengineering and CCS in recent years, and several other political leaders around the globe are doing the same. However, some regions of the world approach geoengineering with caution. eu called for a thorough review of the risks of geoengineering last year, suggesting that international regulations should be established for the eventual implementation of the technology.

Although there is great optimism about the possible success of SMR technologies, there are major concerns about their potential impact on the world’s weather systems. Localized SMR systems are unlikely to be very damaging, but could lead to the use of more advanced geoengineering systems on a larger scale. This suggests the need to create international standards and regulations for the geoengineering industry before an experiment takes place that could impact global weather systems. It is also important that governments do not allow these types of technologies to detract from long-term decarbonisation efforts by allowing companies to ignore the pressure to support a meaningful green transition.

By Felicity Bradstock for Oilprice.com

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