Carbon Dioxide Reduction

By the looks of it, the COVID-19 Pandemic's extensive consequences should have set off a sudden drop in Global Greenhouse Gas emissions, but observational data indicates otherwise. The amount of greenhouse gases in the air — just hit a record high. Figures from Scripps Institution of Oceanography and National Oceanic & Atmospheric Administration (NOAA) indicate the amount of CO2 in the air in May 2020 hit an average of slightly greater than 417 ppm. This is the highest monthly average value ever recorded and is up from 414.7 ppm in May, 2019.

The monotonic rise in CO2 levels may come off as a shock, in light of recent findings that the pandemic, and the associated lockdowns, had led to a steep drop in global greenhouse gas emissions, peaking at a 17 percent decline in early April, but the CO2 figures are also influenced by land surface & oceanic processes. The need of the hour calls for a large-scale withdrawal of carbon dioxide from the atmosphere.

Farmers have long applied limestone to their fields to reduce acidity and provide nutrients, but a new study claims that replacing lime with crushed calcium and magnesium-rich silicate rock could not only help pull carbon from the air but also aid in the agricultural processes. Known as enhanced rock weathering, the process involves layering crushed rock onto the soil. When silicate or carbonate minerals in the dust dissolve in rainwater, carbon dioxide is drawn from the atmosphere into the solution to form bicarbonate ions. The bicarbonate ions are eventually washed by runoff into the ocean, where they form carbonate minerals, storing their carbon indefinitely.

Through extensive modeling and simulations it followed that China, the United States, and India — the three largest emitters of CO2 from fossil-fuel use — have the highest potential for CO2 removal implementing this method, the cherry on top is, however, the fact that spreading rock dust over farmland carries the added benefit that it could help rebuild deteriorating agricultural soils in many parts of the world.

It is crucial to stress that, under optimistic assumptions; enhanced rock weathering will make-up only some of the annual global carbon emissions from fossil-fuel use. Our top priority must always be reducing these emissions for averting dangerous & irreversible climate change.

References:

1. https://www.nature.com/articles/d41586-020-01965-7

2. https://news.un.org/en/story/2020/06/1065732