CO₂ levels are rocketing up.

• The orange line shows how the level of “carbon dioxide in our air” has moved over the last 400,000 years.
• Before 1950, CO₂ levels moved between :
  • lows near 180 parts per million (ppm) during ice ages, and
  • highs near 300 ppm.
• The CO₂ level in 1960 was about 317 ppm.
• The CO₂ level in 2019 is now about 409 ppm. This is 36% above the previous high of 300 ppm.
• The CO₂ level is going up like a rocket.
• See the latest NASA Carbon dioxide graph.

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The CO₂ levels are rising faster

In the 1960s, the increase in CO2 concentration was about one ppm per year. Now, the increase is about 2 ppm per year and getting larger. It may soon be three ppm per year.
Atmospheric CO₂ is accumulating faster than ever (New Scientist, 2006)

If CO₂ continues to increase by 2.0 ppm per year, it will reach 571 ppm by 2100.

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Carbon dioxide levels are alarming.

Over the last hundred years, humans have burnt vast amounts of coal, oil, gas, and wood. This burning has released enormous amounts of carbon dioxide (CO₂) into our atmosphere.

Now we know that carbon dioxide is a greenhouse gas and acts like a blanket over the planet.  It limits the amount of radiant heat that escapes into outer space, thereby warming the Earth. We also know that global temperatures and carbon dioxide levels have moved together for the past 400,000 years. So the current high carbon dioxide levels pose a threat of a substantial increase in temperatures and sea levels.

Carbon dioxide levels above 400 ppm occurred during the Pliocene, which extended from 5.3 to 2.6 million years ago. During this period, the sea level was about 25 metres higher than it is today.

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Our species has never experienced such high levels of CO₂

The concentration of CO₂ in our atmosphere is already far above any level experienced for 800,000 years. Our species, Homo Sapiens, emerged about 250,000 years ago. The species from which we evolved, Homo Erectus and Homo Neanderthalensis, emerged about 400,000 years ago.

Our species, and the web of life that supports us, evolved with CO₂ levels between 180 and 300 ppm.  They have never experienced CO2 concentrations at 409 ppm, let alone the forecast levels. If we allow these high levels of CO2 to persist for an extended period, warming the planet further, we do not know whether the environment that has nurtured our species can survive.

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These high levels of CO₂ risk life as we know it

Carbon dioxide levels influence global temperatures.  While CO₂ levels remain above about 300 ppm, the oven remains turned on –  and we are cooking our planet. (See my page on how fast the planet is heating up.) By maintaining our high levels of CO₂, we risk destroying life as we know it on Earth.

We need to be decreasing the alarmingly high CO₂ levels of 409 ppm,  not increasing it by 2 or 3 ppm each year.

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Modified: 6 Sep 2019