Is it possible to give our climate a makeover?
In the climate change saga, the captivating number is 1.5 degrees. This figure has been baked right into the 2015 Paris agreement! The pledge was signed by more than 195 nations, agreeing to limit global warming to 1.5 degrees Celsius over pre-industrial levels. But seriously, why 1.5? Because, there's a widespread notion that if we let average temperatures rise past that number, reversing the fallout from climate change will be like trying to unring a bell.
Unfortunately, to stay on track, the accord suggests greenhouse emissions need to peak before 2025 and then take a nosedive by almost 50% by 2030. It's clear as day that greenhouse emissions are still on the rise, and we're set to breeze past those 2025 and 2030 targets without breaking a sweat. So, here we are, facing the not-so-fun truth that we’re not just flirting with 1.5 degrees; by 2035, we might just waltz right past 2 degrees! Talk about a hot mess in the next two decades!
So, what now? Well, given the dire and dreary predictions, it seems a little wonder that researchers and scientists are now hoping if human intervention and ingenuity can come into play and actually fix our climate. The concept, referred to as solar geoengineering, looks into exploring techniques to cool down our planet’s temperatures by bouncing sunlight back into the sky. Although largely restricted to scientific journals, the idea itself is not new and has been discussed since the early 2000s. But with temperatures soaring and climate disasters manifesting with increasing frequency, solar geoengineering has been stealing the spotlight lately, breaking out of the confines of scientific journals and making its way into the mainstream conversations.
Solar geoengineering methods all have one thing in common: they use aerosols. One technique is to brighten lower-level clouds by spraying them with aerosols. Known as marine cloud brightening (MCB), this technique uses a spraying cannon to spray small particles that, in essence, brighten the clouds. The second method also gets in on the aerosol action, bouncing sunlight back into space from way up high! Known as stratospheric aerosol injection (SAI), this method involves releasing aerosols like sulfur dioxide way up high in the stratosphere.
Both methods are like a hot potato - highly contentious and fraught with challenges! Aerosols come in all shapes and sizes, each with its own unique characteristics. Aerosols like sulfates and sea salt possess properties that reflect sunlight, while the darker aerosols, like black carbon soot absorb sunlight. The contrasting properties of aerosols can cause unforeseen outcomes. A topic for our next blog!
References:
What is the Paris Agreement. (n.d.). United Nations Climate Change. https://unfccc.int/process-and-meetings/the-paris-agreement
Explained: The 1.5 C climate benchmark. (2023, August 27). MIT News | Massachusetts Institute of Technology. https://news.mit.edu/2023/explained-climate-benchmark-rising-temperatures-0827
Solar Geoengineering Non-Use Agreement. (2022, February 9). What is Solar Geoengineering - Solar Geoengineering Non-Use Agreement. https://www.solargeoeng.org/what-is-solar-geoengineering
Christopher Flavelle. (2024, April 2). Warming Is Getting Worse. So They Just Tested a Way to Deflect the Sun. The New York Times. https://www.nytimes.com/2024/04/02/climate/global-warming-clouds-solar-geoengineering.html
David Gelles. (2024, August 1). This Scientist Has a Risky Plan to Cool Earth. There’s Growing Interest. The New York Times. https://www.nytimes.com/2024/08/01/climate/david-keith-solar-geoengineering.html
NASA Earth Observatory. (n.d.). Aerosols: Tiny Particles, Big Impact. https://earthobservatory.nasa.gov/features/Aerosols
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