To put this into perspective, for nearly 1 million years the atmosphere has contained a carbon dioxide saturation between 180 and 280 parts per million. This has been verified by studying ice cores from the East Antarctic that date back two complete glacial cycles – or 800,000 years ago.
Carbon dioxide is produced through several natural processes (the simple act of breathing, for instance) and the level of atmospheric saturation varies throughout the years and seasons. During summer, more CO₂ is absorbed by plants, which causes the concentration to peak in spring. The increased volume of gas insulates the planet and causes it to warm up.
In this sense, politicians like Florida Senator Marco Rubio are not wrong to say that climate naturally fluctuates. But it does not disprove man-made climate change. Humans have been pumping excess CO₂ into the air for over a century now, and the facts speak for themselves.
Since the Industrial Revolution of the 19th century, the concentration of CO₂ has risen by 40 percent in the Northern Hemisphere. The WMO says that concentration will increase by 2015 at the earliest. Approximately half of all carbon dioxide is absorbed by the Earth’s oceans, which become more acidic as a consequence, endangering marine life and our food supply.
As Dr. Eric Wolff of the British Antarctic Survey explains, “Ice cores reveal the Earth’s natural climate rhythm over the last 800,000 years. When carbon dioxide changed there was always an accompanying climate change. Over the last 200 years human activity has increased carbon dioxide to well outside the natural range.”
Even prior to the WMO’s announcement, almost 200 governments have joined together to try and keep average global temperatures at 2 degrees Celius above pre-industrial levels. This will require significant emission regulations for all nations, as global temperatures have already risen nearly 1 degree celsius above that standard.
“Time is running out,” WMO Secretary-General Michal Jarraud has said. “This should serve as yet another wake-up call about the constantly rising levels of greenhouse gases which are driving climate change. If we are to preserve our planet for future generations, we need urgent action to curb new emissions of these heat-trapping gases.”