Can global warming be reversed?

It is getting warmer out there, and it isn’t an easy problem to solve…

By Sarah Jensen

“There is clear evidence that the global mean temperature is steadily rising,” says Mike Szulczewski, a researcher in MIT’s Juanes Research Group. “The real risk with global warming is if it accelerates so quickly that we can’t respond fast enough.” Whether current climate change is part of a natural cycle or people-generated, the fear is that if left unchecked, the trend could have serious consequences: disrupted plant cycles, the flooding of coastal cities as sea levels change, a breakdown of geopolitical systems across the globe.

What is also clear is the increased level of carbon dioxide in the earth’s atmosphere since the beginning of the Industrial Revolution. “Before the late 18th century, the concentration of CO2 in the atmosphere was about 280 parts per million,” Szulczewski explains. “Currently, it’s approximately 390 parts per million.” A byproduct of burning fossil fuels, CO2 is a so-called greenhouse gas that absorbs and emits infrared radiation. Its buildup in the atmosphere over time means a steady rise in the earth’s average surface temperature.

“The problem is so big that there is no one technological silver bullet for fixing things,” says Szulczewski. Given the geographic, meteorological, and political scope of the situation, studies have focused not on reversing global warming, but on mitigating it by stabilizing the concentration of CO2 in the atmosphere. “In order to do that,” says Szulczewski, “we must reduce our energy usage, increase the efficiency of the energy we do use, and look at solutions like carbon capture and storage.”

Szulczewski and his research team are currently investigating the safety and viability of capturing CO2 emissions from power plants and storing them deep underground. “This is one of the only options that would allow us to continue using fossil fuels,” says Szulczewski.

Everything from the manufacture of toasters to the generation of the electricity to operate them traces back to power plants. In the US alone, the CO2 emitted from fossil fuel burning power plants adds up to about 6 trillion kilograms of CO2 per year, or about 12 trillion pounds.  If the US were to make a dent in those emissions by injecting one sixth of them, the country would have to inject about 1 billion gallons or 40 million barrels of CO2 every day.  This figure is daunting, considering that the US has never extracted more than about 10 million barrels of crude oil a day in its entire history.  Even if we managed to bury enough, Szulczewski says, the effect probably wouldn’t be noticeable for decades. Bringing the atmosphere back to a pre-Industrial Revolution state might take even longer.  

The biggest hurdle of all is the tendency of humans to think in four-year cycles, he says, citing Ruben Juanes, MIT ARCO Associate Professor in Energy Studies. “We have a really good start on technological solutions,” says Szulczewski, “but do we have the political and the social will to think outside the four-year cycle and do something over a very, very long term? It doesn’t seem likely, in the near future at least, that people are going to change their habits and stop using fossil fuels.” 

Thanks to 18-year-old Jose Luis Segura B. from San Jose, Costa Rica, for submitting this questions.

Posted: April 24, 2012