CO2 Levels in the Atmosphere

Last week atmospheric carbon dioxide as measured at NOAA’s Mauna Loa Atmospheric Baseline Observatory reached 420 parts per million (ppm), the highest level since accurate measurements began 64 years ago according to scientists from NOAA and Scripps Institution of Oceanography at the University of California San Diego. According to NOAA, mankind is adding roughly 40 billion metric tons of CO2 pollution to the atmosphere per year - mostly because of the fossil fuels that people are burning for energy. 

Each year we put more carbon dioxide into the atmosphere than natural processes can remove, which means the net global amount of carbon dioxide rises. As long as emissions continue, global temperature will continue to rise. Given the long life of CO2, the temperature level already observed will persist for decades even if emissions are cut to net zero. Alongside rising temperatures, scientists predict more weather extremes including intense heat and rainfall, ice melt, sea-level rise and ocean acidification. Despite promises made by the nations the CO2 level in the atmosphere has risen every year since measurements began.

The highest monthly mean CO2 value of the year occurs in May, just before plants in the northern hemisphere start to remove large amounts of CO2 from the atmosphere during the growing season. In the northern fall, winter, and early spring, plants and soils give off CO2, causing levels to rise through May.

CO2 pollution is generated by emissions from carbon-based fossil fuels used for transportation and electrical generation, by cement manufacturing, deforestation, agriculture, and many other practices. Along with the other greenhouse gases, CO2 traps outgoing heat from the planet’s surface that would otherwise escape into space, causing the planet’s atmosphere to warm steadily.

As the concentrations of CO2 and the other greenhouse gases in the atmosphere increase the warming produced by the greenhouse gas effect is strengthened. CO2, methane, nitrous oxide and water vapor are the major greenhouse gases.  Computer modeling of the climate predicts that there will be feedbacks that significantly increase the impact from the increasing CO2. Mankind produces carbon dioxide from power plants, transportation (cars, trucks, planes, trains, and ships), heating, cement manufacture, deforestation, and breathing. Methane is produced from agriculture, livestock, mining, gas pipeline leaks and well heads, landfills, and sewage plants. Nitrous oxide is produced by fertilizers, fossil fuel combustion, animal waste, polluted waters, and chemical processes.

The climate models show that there is nothing that we can do at this point to prevent global warming and climate change even if the concentration of CO2 in the earth’s atmosphere did not continue to rise. Global warming and sea level rising will continue for decades because of the time scales associated with climate and planetary feedback loops.

In reality, the global emissions of CO2 will probably continue to rise for at least a generation possibly more. What is going to happen will happen. I will leave it to others to argue the case for the accuracy of climate models and the time scale to achieve net zero; however, both mankind and the earth itself will respond to changes in CO2 concentrations and temperature, but not before it becomes the pressing concern of the currently rapidly growing and emerging nations. Though the nation constantly argue, discuss and meet, the promises made by nations are not adequate to reverse the climate trend.

We need to face some tough realities. We have not been able to even stabilize the world CO2 emissions. As each region or county industrializes the world CO2 emissions have grown. Even in the United States and European Union the decarbonization of the electric grid is going to take much longer than we hoped. The technology is just not there yet. It is unreasonable to expect that climate goals can be met without rationing power use.