Last month saw yet another unwanted record registered by the Mauna Loa Observatory in Hawaii: for the first time, 410 ppm (parts per million) was exceeded for an entire month of observations. The result? An average of 411.24 ppm. The safety threshold, considered such in order not to radically alter the climate as we know it, was 350 ppm. The measurement was carried out by the Scripps Institution of Oceanography at the University of California San Diego, which since the 1960s has developed a method for measuring the greenhouse gas present in the atmosphere. "We keep burning fossil fuels and CO2 keeps going up," said Ralph Keeling, director of the Scripps CO2 programme and son of the creator of the Keeling Curve, Charles David Keeling. As explained by researchers at Noaa (the US National Oceanic and Atmospheric Administration), these are levels never reached in the previous 800,000 years — that is, as far back as we are able to measure atmospheric CO2 concentration. At that time, average temperatures were approximately 2–3ºC higher.

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It is not the first time CO2 emissions have exceeded the 400 ppm threshold

The 400 ppm mark had already been breached in 2013, but the real peak was recorded in 2016, when researchers were in agreement that levels would be unlikely to drop below 400 again. And that from that moment on we would have to live with the fact that, even if we were to stop emitting the greenhouse gas right now, it would take decades for values to return to normal. What normal? In 1958, the year the Keeling Curve was born (which measures the variation in atmospheric CO2), values stood at 315.

According to research published in Nature Communications, at the current rate we could reach the greenhouse gas levels recorded during the Eocene (50 million years ago), a period during which average temperatures were 10 degrees higher and the polar ice caps were completely free of ice, with the consequences that are by now well known.

The albedo question

The melting of the ice does not only entail the loss of a large part of the planet's freshwater reserves. With it, the albedo effect also weakens — the phenomenon by which ice reflects part of solar radiation, keeping temperatures lower (solar energy is partly dispersed).

In 2017, CO2 emissions also increased in Europe

According to recent data released by Eurostat, CO2 emissions from the combustion of fossil sources grew by 1.8 per cent compared with previous years. Germany remains the largest emitter, accounting for as much as 23 per cent, followed by France and Italy (both at 10 per cent) and Poland — the coal country par excellence.

By continuing to ignore all the signals, which arrive in unison from both the scientific world and from objective reality and common perception, we will have no choice but to hand down to future generations a world that is hotter, thirstier and different from the one we have known.