Although not tangible (or visible), purchasing a Cool Effect gift card is a great way to take a page out of Greta’s book and reduce CO₂ emissions – if they need to fly and can’t charter a yacht to cross the Atlantic. Cool Effect is an organization on a mission to reduce carbon emissions through a variety of science-backed sustainable projects. There a number of gifts you can buy, including one cheeky ‘Poo Package’ to fund a biogas digester which turns waste into energy, but we recommend buying travel offsets. You can tailor this to your recipient’s holiday flights or future travel to neutralize their airplane carbon emissions.