Inspired by 16-year-old Swedish activist Greta Thunberg’s weekly protests, the global youth climate movement has spread all over the world, with students organizing strikes on every continent. Here are some things that you should know about climate change.
Why is the climate on Earth changing? As the rays of the sun enter the Earth’s atmosphere, most of the heat is released back by our planet. But some of that heat stays back, trapped by the Green House Gases (or GHGs like carbon dioxide) in the atmosphere. The good news is that GHGs are needed in moderation to sustain life on Earth.
But the problem is that since the Industrial Revolution which took place in the 18th and the 19th century, humans have been pumping too many GHGs into the atmosphere by burning fossil fuels. According to a study, more than 2,000 gigatons (a gigaton is one billion metric tons) of carbon dioxide have been released into the atmosphere since then.
This thickening blanket of heat-trapping greenhouse gases has led to an increase in the average temperatures around the world. If nothing changes, their impact on the earth will continue to intensify. What kind of impact? Things like forest fires, stifling heat waves and rising sea levels to name a few.
How do we stop global warming? We need to take immediate steps to reduce these emissions by increasing our use of renewable energy and halting deforestation. But according to the latest climate science research, these efforts alone aren’t enough to prevent climate change.
So what can we do? Climate scientists are exploring an alternative solution to climate change. It’s called geoengineering: ways to suck out extra carbon dioxide generated by human activity, from the air. This carbon then needs to be stored somewhere and hopefully reused.
It also includes efforts to reduce the amount of direct sunlight hitting the earth – like spraying something in the clouds to increase their reflectivity.
How much is enough? According to the United Nations’ Climate Panel, we need to remove as much as 1 trillion tons of Co2 from the atmosphere this century. 350 parts per million (ppm) is the safe level of carbon dioxide molecules in the atmosphere. We are already above 400 ppm. That means that we not only have to curb further emissions, we will also have to remove and store some of the existing carbon from the atmosphere.
What are some efforts being explored for capturing carbon from the atmosphere?
Direct Air Capture is a new technology that involves the use of machines equipped with chemicals that can soak up carbon from the atmosphere. A few start-ups, such as Climeworks in Switzerland and Carbon Engineering in Canada, have demonstrated that this can be done, although the costs are still high. Carbon Engineering will use the captured carbon dioxide as a key ingredient for the production of its synthetic fuels. Climeworks will produce methane from captured carbon dioxide and hydrogen and also sell carbon dioxide to the soft drinks industry. There is a decent chance that machines can capture carbon for less than $100 a tonne in the future, but it will take years for costs to fall anywhere near that level.
Carbon mineralisation is another technique that involves exposing rocks such as basalt that react with carbon dioxide which then gets trapped, thus turning it into mineral. This has been done successfully in Iceland, although the technique is still expensive.
Have you heard of other ways to capture carbon from the atmosphere? Write in at email@example.com!
Written by: Chandni Shah. Chandni is a picture book collector, an educator and founder of Simplifly, a learning venture for children.