Carbon dioxide concentrations in the atmosphere reached yet another record level for the month of May, just short of 419 ppm. It is the highest concentration in the 63 years the data has been recorded.
This graph depicts the upward trajectory of carbon dioxide in the atmosphere as measured at the Mauna Loa Atmospheric Baseline Observatory by NOAA and the Scripps Institution of Oceanography. The annual fluctuation is known as the Keeling Curve. Credit: NOAA Global Monitoring Laboratory Photo: NOAA Global Monitoring Laboratory
That value, measured at the National Oceanic and Atmospheric Administration’s Mauna Loa observatory, is up from the May 2020 value of 417 parts per million (ppm). It also compares to carbon dioxide concentrations of less than 320 ppm when measurements were started in 1958.
It is also over 50% higher than estimates of pre-industrial CO2 concentrations for the first time.
The May metric for CO2 concentrations is the most important of the year. It is always the peak value annually, driven by seasonally varying human usage of fossil fuels with the highest consumption happening during the winter months. It is also timed just before plants and trees begin their spring growth in the northern hemisphere, helping to absorb some of the emissions at least for some months.
This year’s number was eagerly awaited. Scientists wanted to see what the impact of the global lock downs, industrial cutbacks, and worldwide curtailment of vehicle use and air travel might have on the number. What they found was disturbing, on two fronts.
The first was that carbon dioxide concentrations in the atmosphere were up only slightly less than what they would have been even without the pandemic. While the 1.8 ppm increase was slightly less than the average increase of 2.3 ppm, researchers believe factors such as the increased wildfires in Siberia starting about a year ago as well as other wildfires which spread across the world last summer helped drive carbon dioxide emissions higher even without human beings having directly caused all of them this time. Total emissions were up by a significant amount despite that global human-driven carbon dioxide pollution in fact dropped by 6.4% overall.
This is strong evidence that secondary climate change effects have begun to take hold of the planet. Their presence means carbon dioxide emissions will continue to increase and even accelerate now, even if we had the collective will and courage to halt immediately all fossil fuel use on the planet.
A second concern the scientists noted was that carbon emissions pushed into the atmosphere increased by 2.3 ppm for the first five months of 2021, relative to the same CO2 concentrations present in the first five months of 2020. That 2.3 ppm is identical to the entire annual increase in CO2 concentrations averaged out over several years.
That means carbon dioxide emissions concentrations are accelerating.
The current carbon dioxide concentrations in the atmosphere not only are the highest ever, they are also – based on a variety of scientific data – the highest since the Pliocene era some 4.1 – 4.5 million years ago. Then the Earth’s sea levels were 78 feet (24 meters) higher than they are today.
The news of the carbon dioxide concentration increases comes as much of the North American continent is sizzling with record high temperatures and the American West in deep in a prolonged drought which could last much of the rest of this century.
It also comes as temperatures in multiple locations across the Middle East hit dangerous new high temperatures of over 125° F (52° C). Temperatures this past weekend reached 125.2° (52° C) in Sweihan, located 50 miles east of Abu Dhabi in the United Arab Emirates, 123.8° (51° C) in Omidieh in southwestern Iran, and 123.6° (50.9° C) in Jahra, Kuwait. Max Herrera, a climate historian, noted as this happened that “the Middle East and Central Asia are under the harshest heat wave in history for this time of the year.”
These numbers are consistent with researchers noting that parts of the Middle East will soon become so hot as to be unihabitable. With temperatures as high as recorded this past weekend, the human body’s system of expelling sweat to cool the skin is unable to bring body temperatures down fast or fully enough to prevent heat stroke and death.
The increased carbon dioxide emissions concentrations are about to make such extreme temperatures far more common, as well as happening in places new to such high heat. While cutting fossil fuel use drastically around the planet will help slow the rate of this increase, the presence of the secondary effects which definitively pushed CO2 concentrations up beyond human-only levels for the first time this year means the planet will continue to get hotter faster for many decades to come.
It is time for a better solution than just cutting greenhouse gas emissions to save the planet and as many species as possible, as the climate crisis intensifies.
We need a lifeboat and new tools to navigate the future.