The levels of carbon dioxide in the Earth’s atmosphere have risen above the symbolic number set by scientists to signal a crisis, says the UN's World Meteorological Organisation (WMO). No longer teetering on the edge, we have tipped over into disaster.
Last spring, the average monthly concentration passed 400 parts per million (ppm), announced the annual Greenhouse Gas Bulletin.
“There’s nothing magic about 400,” Dr. Oksana Tarasova, the head of the WMO’s Atmospheric Environment Research Division, told the New York Times, explaining that it is just an arbitrary number selected by climate change scientists as the level beyond which they would rather not see the atmosphere go. But, the “evidence shows that the concentrations are increasing and they are increasing with increasing rates.”
In his film, An Inconvenient Truth, released nearly ten years ago, Al Gore explained that the more the levels increased, the faster change would happen. He had been presenting the slide-show on which the film is based since 1989, sounding the alarm but also encouraging individuals to make changes in their lives which, cumulatively, could save our planet from destruction.
The Kyoto agreement represented an attempt to coordinate the international response to global warming, but unfortunately, the two largest contributors of carbon dioxide emissions—China and the United States—refused to be bound by it. Agriculture and deforestation, burning fossil fuels, and cement production are the worst offenders by far, and regulation of these things must happen at a national and international level. China only began monitoring air quality officially in 2013, although it has had terrible problems with smog for years. Recently, air levels of particulates measuring less than 2.5 microns reached 50 times the WHO safe percentage in one Chinese city. These particulates are especially dangerous because they can be inhaled into the lungs and bloodstream, causing severe health problems.
The other greenhouse gasses, methane and nitrous oxide, are also on the rise, with methane at more than twice the levels seen before the industrial revolution, and nitrous oxide at 20 times the pre-industrial levels.
The WMO released graphs showing that emissions levels have risen every single year since 1984, when records began. “Every year we say that time is running out, and this year just adds to this pressure,” said WMO Secretary General Michel Jarraud. “It is very important these figures are taken into account by the negotiators [at the climate summit in Paris].”
As the levels of greenhouse gasses rise, so does the global temperature. This year represented an overall rise of 1 degree Celsius since the eighteenth century. If the temperature rises more, some parts of the world will no longer be inhabitable, either because rising ocean levels will drown them or the heat will be unbearable. A report in Nature Climate Change said that lethal heat waves in the Persian Gulf could be incompatible with human life by the end of the century.
In one slightly more encouraging development, the hole in the Earth’s ozone layer is expected to disappear by 2070, thanks to the limiting of CFCs, once used in refrigerators and aerosols. Discovery of the hole in the late 1970s led to the Montreal Protocol, signed by 196 countries, which eliminated CFCs. Although the hole gets larger and smaller, depending on the season and the year, it reached its record size in 2000 and is not getting larger. This shows that it is possible to effect change on a global level, and we hope that the participants at the Paris conference will be inspired by this.