Latest calculations from the blog - Page 5
That viral claim — you eat a credit card's worth of plastic every week — already has a very aggressive assumption baked in. Change it, and the lifetime total swings from 76 cards to over 4,000. One variable, a 50-fold range. Here's how the math actually works.
A cotton tote bag has a much larger production footprint than a plastic bag. The break-even point is 52–131 uses under GWP alone, or up to 7,100 uses if ozone depletion is factored in. Average real-world use? About 51 times. And individual savings amount to roughly one 89-billionth of the annual global production growth in carbon terms. Two reversals, one calculation.
A PET bottle tossed into the English Channel during the Spanish Armada (1588) would still be intact today — with 12 years left on the clock. PET takes roughly 450 years to degrade in marine conditions, and that timeline gets much worse in a landfill. We calculate polymer breakdown timelines, the cube-law fragmentation math that turns one bottle into 18 trillion particles, and why NOAA still can't give you a definitive answer.
Since 1950, humanity has produced roughly 8.3 billion tonnes of plastic. Split evenly by world population, that comes to over a tonne per person — yet only 9% was ever recycled, and 886 kg of your share is sitting in a landfill or the ocean right now. We run the numbers and show how much the recycling rate actually matters.
Over a lifetime, a human produces roughly 5,249 kg of stool — about the weight of an adult African elephant. We calculate what fraction of your daily calories exits unused, why a vegan diet scores 74% digestive efficiency while a low-fiber diet hits 93%, and what Kleiber's Law tells us about why mice produce more waste per kilogram than elephants.