Monday, April 02, 2012

When Should Activists Plan for 400 ppm?

This is the time of year when the preponderance of the plant life on the planet is dead or dormant -- most of it being in the northern hemispheric, because that's where most of the land is -- so the plant community isn't breathing much, so atmospheric CO2 levels are rising. And at Mauna Loa (MLO) they just hit a new high and crossed over 395 ppm for the first time:

The level will continue to rise until late May, though the exact amount varies, from this point in the year, from about 0.5 to 1.5 ppm.

So when will MLO CO2 first top 400 ppm? I suspect climate activist groups are already planning a huge campaign to mark the occasion -- it would be foolish for an activist not to.

The slope of the linear trend in the above graph is 1.88 ppm/yr, so assuming this year tops out at about 396 ppm, 400 ppm should be reached in either 2014 or 2015.

Topping 400 ppm will be possible in 2014, but not a sure thing, especially if this year tops out higher than 396 ppm. But to be safe that's what the's of the world need to plan for, though they might have to put their media package on hold in June 2014 and save it for the next year, when "400" will definitely happen.

(Yes, surely there will be some CO2 monitors somewhere in the world that will reach 400 ppm earlier, and probably some near strong CO2 sources already have. But Mauna Loa is the most famous monitoring site, so it will be the one that really matters.)


Anonymous said...

FYI on Tallbloke's Talkshop I tried telling the Tallbloke that you knew what you were talking about re thermodyanmics. It appears he banned me. None of my comments are showing up. Make mention of what he did if you get the chance.

Anonymous said...

Oops I though that was going to give me a chance to enter my name an a URL before it was published.

David Springer

David Appell said...

Thanks for letting me know. It also seems he's selectively approving only some of my comments now.

I've found this often on such blogs -- as soon as you show you know what you're talking about and how standard physics accounts for something they're touting, they ban you.

bahamamamma said...

There is no magic in 400 ppm.

There is reason to believe that the Earth's atmosphere was once mostly composed of CO2 with very little oxygen.

Then primitive life forms started to excrete oxygen and the oxygen reacted with the iron dissolved in the oceans, creating layers of iron ore.

Once the dissolved iron was consumed the atmosphere began to have a rising concentration of oxygen.

By the time the first life forms gained a foothold on land the CO2 concentration had fallen to about 25 times what we experience today.

If you want to panic about CO2 concentration just remember that many of the plants we eat cannot survive if CO2 falls below 150 ppm.

Dano said...

Nothing bahamamamma wrote has anything to do with biota and their adaptations to conditions of today, but thanks ever so much for typing it!! Good job of typing!



charlesH said...

A Party?

"Putting aside for the moment the question of whether human industrial CO2 emissions are having an effect on climate, it is quite clear that they are raising atmospheric CO2 levels. As a result, they are having a strong and markedly positive effect on plant growth worldwide. There is no doubt about this. NASA satellite observations taken from orbit since 1958 show that, concurrent with the 19 percent increase in atmospheric CO2 over the past half century, the rate of plant growth in the continental United States has increased by 14 percent. Studies done at Oak Ridge National Lab on forest trees have shown that increasing the carbon dioxide level 50 percent, to the 550 parts per million level projected to prevail at the end of the 21 century, will likely increase photosynthetic productivity by a further 24 percent. This is readily reproducible laboratory science. If CO2 levels are increased, the rate of plant growth will accelerate."

Dano said...

they are having a strong and markedly positive effect on plant growth worldwide...If CO2 levels are increased, "the rate of plant growth will accelerate."


Old-school talking points aside, I'll take those 2 points Charles leaves on the table.



Hermundur Sigurdsson said...

CO2 level have already reached 400 ppm in the Westman Islands in Iceland. This happened during spring of 2011.