How can we, apart from any sufficient public policies, influence citizens to reduce CO2 emissions? The family showed their results within 20 hours. It was in the isolated village of Lot that the couple decided to settle. He is a computer engineer, she is a factory operator. The children have left, they have renovated their small house. For the France 2 teams, they calculated their carbon footprint on a dedicated website. The result: 8.3 tons of CO2 per person per year, slightly less than the national average (9.9 tons), but still very far from the carbon neutrality target set at 2 tons. The worst thing is their transport, with 3.3 tons of CO2. The couple own two cars and they cannot do without them in the countryside. Their strong point is the accommodation, which weighs only 0.6 tons, because the house is insulated, heated by a wood stove and without air conditioning in the summer. (Delion, M. Martel, A. Maurisson, A. Tribouart, N. Trau)