Atmospheric carbon dioxide (CO2) concentrations in the atmosphere have peaked for the year at 430.5 parts per million (ppm). Data from the National Oceanica and Atmospheric Administration (NOAA), recorded that this latest annual reading was 3.61ppm higher than May last year. In the past 50 years, we have seen the atmospheric concentrations of CO2 rise by roughly 100 ppm – a devastating indication of human-induced climate change.
The UN’s World Meteorological Organisation said in its annual report that these record greenhouse gas concentrations are the highest in at least two million years, with levels of methane also at levels not seen for hundreds of thousands of years. “Current atmospheric concentrations of CO2 are higher than at any time in at least two million years. Concentrations of CH4 and N2O are higher than at any time in at least 800 000 years.”
At the time of the Industrial Revolution, atmospheric concentrations of CO2 remained relatively stable around 280 ppm. Since then, human activities, through both the burning of fossil-fuels and deforestation, have driven a stark increase in the concentration of CO2 of around 50% in just 200 years – potentially an unprecedented rate of increase.
What is the impact of rising carbon dioxide concentrations?
Michael Mann, presidential distinguished professor of earth and environmental science at the University of Pennsylvania and author of the forthcoming Science Under Siege, took the time to distinguish between CO2 concentrations and CO2 emissions, when he told Yorkshire Bylines:
“Regarding carbon dioxide levels, this has come up many times on social media, and there is a lot of confusion out there, much of it regarding the distinction between CO2 concentrations and CO2 emissions. We expect the former to rise steadily as long as anthropogenic emissions exceed natural CO2 uptake (which requires emissions reaching near zero levels).”
He continued: “So expect CO2 concentrations to rise until human emissions come down substantially. Right now, emissions have basically stabilized and accordingly the annual increase in atmospheric CO2 has stabilized (it spiked in 2016 and 2024 due to major El Nino events but if you neglect those individual spikes, the data show a clear leveling.)”
He warned though that: “the bad news is that stabilizing emissions obviously isn’t adequate. If we want to see atmospheric CO2 level off, as noted above, we need to bring emissions down substantially in the years ahead. The best current modelling indicates that carbon emissions must be reduced 50% relative to 2019 levels if we are to have any hope of limiting warming to 1.5C. Current policies are not adequate to accomplish this so there must be substantial additional actions to accelerate the clean energy transition currently underway.”
Limiting warming and global emissions
Because there is an association between CO2 concentrations and temperature, this means that as the concentrations of CO2 rise, we can expect to see enhanced global warming, ocean acidification and more climate-change-related extremes around the world. A 2001 study, which examined the relationship between CO2 levels and global temperature over hundreds of millions of years, concluded that: “This means that over the long term there is indeed a correlation between CO2 and paleotemperature, as manifested by the atmospheric greenhouse effect.”
Bill McGuire, professor emeritus of geophysical and climate hazards at UCL, told Yorkshire Bylines: “It barely made the news, but a landmark observation was made a few days back. Atmospheric carbon dioxide levels topped 430ppm for the first time in human history, following a huge rise across the previous calendar year of 3.6ppm. Prehistoric CO2 levels are now not only locked-in, but they will continue to climb as governments and corporations actively turn away from promised green measures.”
McGuire continued: “If there is a glint of light at the end of a very dark tunnel, it’s that China’s emissions have begun to fall this year, and may have peaked. Practically speaking, however, this will be nowhere near enough to prevent growing climate mayhem as the global average temperature heads for the 2C mark, possibly as soon as the 2030s.”
Net zero pathways are critical
How do we begin to put a brake on the rising CO2 concentrations in the atmosphere? Thankfully, we already know how to do this. The solution is a political one, not some miracle scientific breakthrough, using a nascent technology which has never been used at scale.
The IPCC Special report on ‘Global Warming of 1.5℃’ states clearly that: “Limiting warming to 1.5℃ implies reaching net zero CO₂ emissions globally around 2050 and concurrent deep reductions in emissions of non-CO₂ forces, particularly methane.”
It is deeply alarming then, that some UK politicians at least, appear to treat the legally binding obligations of the net zero target, created through the Climate Change Act 2008, as a nuisance and inconvenience, rather than the necessary climate action that is required.
Sadly, with this mindset in place, it may be that a year from now we once again report that CO2 concentrations have reached a new record high in human history, only to find that this news is met with indifference at best.
