Transport produces a considerable share of greenhouse gas emissions.
The concentration of CO2 in the atmosphere has reached in May a level 50% higher than in the pre-industrial era, unheard of on Earth for about four million years, alerted an American agency on Friday.
Human-caused global warming, including fossil fuel-fired electricity generation, transportation, cement production and deforestation, is clearly responsible for the new spike, the agency said. American Ocean and Atmospheric Observatory (NOAA).
May is usually the month with the highest carbon dioxide levels recorded each year.
In May 2022, the bar of 420 parts per million (ppm), the unit of measurement used to quantify pollution in the air, was crossed. In May 2021, this rate had risen to 419 ppm. And in 2020, it was 417 ppm.
These measurements are taken at the Mauna Loa Observatory in Hawaii, conveniently located high on a volcano, which allows it not to be affected by local pollution.
Prior to the Industrial Revolution, the CO2 level hovered consistently around 280ppm for the nearly 6,000 years of human civilization that preceded it, according to NOAA.
The level reached today is comparable to what it was between 4.1 and 4.5 million years ago, when CO2 levels were near or above 400 ppm, the agency said in a statement.
Back then, the sea level was 5 to 25 meters higher than it is today, enough that many of today's major cities lie under water. And vast forests occupied parts of the Arctic, studies show.
CO2 is a greenhouse gas that has the effect of trapping heat , causing the gradual warming of the Earth's atmosphere. It remains in the atmosphere and in the oceans for thousands of years.
This warming is already having dramatic consequences, recalled the NOAA, including the multiplication heat waves, droughts, fires and floods.
“Carbon dioxide is reaching levels that our species never #x27;has ever experienced in the past, which is not a recent phenomenon. We've known that for half a century and we've failed to do anything meaningful. What will it take to wake us up?
—Pieter Tans, scientist with NOAA