Free Astronomy Magazine January-February 2022

JANUARY-FEBRUARY 2022 T he Earth Overshoot Day marks the date when humanity’s de- mand for ecological resources and services in a given year exceeds what the Earth can regenerate in that year. In 2021, that date was July 29. The infographic shows what the Overshoot Days would have been if the entire world population had burned resources at the rate of the populations of the nations indicated. ecologist on duty recharges his green car, he has already given his contri- bution of CO 2 even before starting the electric motor (and we avoid dwelling on the damage caused to the environment by the supplying of raw materials necessary for the man- ufacture of rechargeable batteries). 2) Exploiting the only unlimited, re- newable, and spread all over the planet source to produce electricity − the Sun. If we consider that the world’s electricity consumption amounts to approximately 24,000 billion kilowatt-hours/year and that a good one-square-meter solar panel produces, with average values of solar radiation, about 200 kilowatt- hours/year, it would be necessary to cover an area as large as Pennsylva- nia with solar panels to give up all the most polluting forms of energy. Currently, only about 3% of the consequence of those practices and activities associated with them, di- rectly or indirectly polluting and co- responsible for the increase in at- mospheric carbon dioxide levels. As obvious as they may be, the solu- tions proposed to tackle global warming are either poorly applica- ble or impracticable in the near fu- ture. Two simple examples should be quite illuminating: 1) Replacing fossil fuels with renew- able sources − essentially with elec- tricity. Great idea, but it is a pity that, in 2020, over 63.3% of global electricity production took place by burning fossil fuels (64.8% in 2000, so practically no progress in the last 20 years), and that part of the re- maining 36.7% includes nuclear, methane (a potent greenhouse gas) and low, but not zero, carbon-con- tent fuels. Consequently, when the their existence to well-defined terri- tories. Since we stopped following our prey in their periodic migrations and began to take advantage of the fruits made available innately, pre- ferring instead the “certainties” of- fered by agriculture, stock rearing and industry, we have begun to suf- fer more and more from climatic phenomena, which are gradually becoming extremes precisely as a