Conventional, non-renewable sources of energy (e.g. oil, coal, natural gas) have been forming for millions of years and are thus non-renewable in our lifetime. Fossil fuel extraction has been steadily increasing: 50% of the 11.7 gigatons extracted was done in the last few decades. If the current rate of extraction is continued, these sources are projected to be depleted quickly. In Raisa Rahim's next installment, she takes a deep dive into the sustainability (or rather unsustainability) of fossil fuels.