CO2 rose by a record amount last year

“The accumulation of CO2 in the atmosphere is irreversible on human time scales and will affect the climate for millennia.” — World Meteorological Organization (WMO)

Despite decades of global efforts to prevent a full-blown climate crisis, its main driver, CO2, continues to accumulate in our atmosphere at an accelerated rate. throttle rate. And last year’s CO2 increase broke extreme records.

Annual increase of CO2 in the atmosphere from 1963 to 2023. (NOAA Mauna Loa)

My first chart shows the most recent data from the National Oceanic and Atmospheric Administration (NOAA). The gray bars mark the increase in CO2 in each of the last 60 years. And I have highlighted those from 2023. “out of series” increase in red.

Last year, CO2 increased by 3.36 parts per million (ppm). That’s a 10 percent jump from the previous record, which was set just a few years ago.

In terms of weight, last year’s increase added a record 26 billion tons of CO2 to the atmosphere, more than three tons per human.

At the microscale, about 84 trillion new CO2 molecules were added to each cubic centimeter of Earth’s atmosphere last year. A cubic centimeter is about the size of a sugar cube. (Note: For details on the mathematics of atmospheric CO2, see endnotes.)

And for a deep-time comparison, take a look at the dashed line on the chart, at the bottom. That’s the pace that destroyed Earth’s last ice age,

Map showing the northern ice sheet over Canada during the last ice age.  USGS Public Domain.

During the last ice age, about 20,000 years ago, all of Canada was buried under a huge sheet of ice in the north. the ice was two miles thick over the Montreal region and a mile thick over Vancouver. There was so much water trapped in ice that global sea level was 125 meters (410 feet) lower. We are talking about a lot of ice and a radically different climate.

Like NOAA highlighted: “The rate of CO2 growth over the last decade is 100 to 200 times faster than what the Earth experienced during the transition from the last ice age. “This is a real shock to the atmosphere.”

Accelerating away from climate security

As you may have noticed, the gray bars on the graph change a lot from year to year. This is mainly due to short-term fluctuations in the amount of CO2 that plants and global oceans absorb each year.

Despite decades of global efforts to prevent a full-blown climate crisis, its main driver, CO2, continues to accumulate in our atmosphere at an accelerated rate, writes @bsaxifrage.

Annual increase of CO2 in the atmosphere from 1963 to 2023 with decadal averages.  (NOAA Mauna Loa)

So, to better show the underlying long-term trend, NOAA uses decade averages. I added these 10-year averages to my chart as a series of black horizontal bars.

For example, during the first decade shown in the graph (1963 to 1972), atmospheric CO2 increased an average of 1.00 ppm per year. That’s the leftmost black bar.

Notice how those black bars have gotten higher and higher? They have ignored three decades of global climate conferences that tried to slow them down, reaching a dizzying average of 2.38 ppm per year over the previous decade.

And that doesn’t even include last year’s epic surge.

As this chart clearly shows, annual increases are increasing. When the increases increase, you are speeding up. And when you do that with him primary control knob of the Earth’s climate (CO2), we are rapidly moving away from climate stability and security.

Net zero?

To prevent the climate crisis (and its evil twin, ocean acidification) from becoming increasingly extreme and dangerous, CO2 levels in the atmosphere must stop rising.

Annual increase of CO2 in the atmosphere from 1963 to 2023 with decadal averages.  (NOAA Mauna Loa)

That point at which CO2 stops increasing is called “net zero” and is literally the zero line at the bottom of the graph. I have highlighted this zero CO2 increase line in green.

Net zero is one of those clear goals. Getting closer is not enough.

To understand why, look again at the dashed line just above.

As we saw above, even such small CO2 increases were enough to radically alter the global climate. That pace melted ice sheets the size of Canada, flooded coastlines and forced important ecosystems to migrate thousands of kilometers or perish.

And yet, Canada alone currently emits far more CO2 each year than that dashed line.

So, it’s net zero or bust.

What will it be?



Interested in doing some geeky calculations on CO2? These are the general rules I used in my general calculations.

CO2 molecules

  • One cubic meter of air contains approximately 25 million billion (1024) molecules (fountain).
  • Each cubic meter contains one million cubic centimeters (cm3). Thus, each cubic centimeter contains around 25 million trillion (1018) molecules.
  • One part per million (ppm) of that = 25 trillion (1012) molecules.
  • Adding 3.36 ppm to the atmosphere requires adding approximately 84 trillion molecules per cubic centimeter (25 trillion * 3.36).

CO2 weight

  • 7.81 billion tons of CO2 (GtCO2) are needed to increase atmospheric CO2 by one ppm (fountain).
  • The weight of 3.36 ppm atmospheric CO2 is approximately 26 GtCO2 (7.81 GtCO2 * 3.36).

Extra geek-out: Did you know that every kilogram of fossil fuel CO2 we emit adds another molecule of CO2 to every cubic centimeter of the atmosphere? Here’s the math:

  • avogadro’s constant says that 44 grams of CO2 contain about 6 x 1023 CO2 molecules. Thus, each kilogram of CO2 (kgCO2) contains around 1.37 x 1025 CO2 molecules.
  • Approximately 44 percent of the CO2 emitted remains in the atmosphere. The rest is absorbed fairly equally by the ocean (ocean acidification) and increased photosynthesis.
  • Thus, for every kilogram of CO2 emitted, around 6 x 1024 CO2 molecules remain in the air. That’s about how many cubic centimeters there are in the atmosphere!
  • The “effective volume” of the atmosphere is about 4.2 billion cubic kilometers (fountain), which is 4.2 x 1024 cubic centimeters.
  • Burning a single liter of gasoline emits 2.4 kgCO2. That’s enough to add about three CO2 molecules for every cubic centimeter of the planet’s atmosphere. Oh, and the part absorbed by the oceans adds about six CO2 molecules for every cubic centimeter of the world’s oceans. That gives a whole new meaning to “fill it up!”

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