
As Carbon Dioxide Levels Rise, Major Crops Are Losing Nutrients - reirob
https://www.npr.org/sections/thesalt/2018/06/19/616098095/as-carbon-dioxide-levels-rise-major-crops-are-losing-nutrients?t=1529475584040
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teekert
> The chamber is really bright to mimic the sun. A few neat rows of green
> coffee plants are growing. The air that they're absorbing has about the same
> amount of CO2 as in the preindustrial age, about 250 years ago.

> Across the hall, we can see a possible glimpse of the plant's future. Here,
> there's a chamber with plants growing at CO2 levels projected for the end of
> this century.

> "Some of the varieties, you ought to see that they're bigger," says Ziska.
> They've all been growing for the same amount of time, but the high CO2
> coffee plants are larger. The extra CO2 seems to be making them grow faster.

> Scientists have noticed that in many kinds of plants, higher CO2 produces
> bigger crops. That sounds like a good thing.

> But there's a problem. Bigger doesn't necessarily mean better. And while
> they're still testing what this means for coffee's quality, scientists have
> seen that other crops have lost some of their nutritional value under higher
> CO2 conditions.

If they are bigger they absorb (or have absorbed) more CO2 into their
carbohydrates, I wonder what the effect is on CO2 levels in the atmosphere, is
this taken into account in all the models? Moreover, how were the effects when
compensated for the increased mass of the plant? Were there the same amount of
nutrients but just more carbohydrates and water? If so, other ways of
preparing the food may help.

~~~
acqq
> is this taken into account in all the models

It is in the relevant ones (having “all” in the question makes the question
not meaningful).

Not only it is in the relevant models, but modelling all the effects includes
the aspects that the most probably would never think about. E.g. “bigger
crops” store C but it is “returned back” after harvesting. What matters is
only what can permanently store C.

~~~
teekert
Good points but Jungles or Taigas can now also have more mass presumably. I
guess that is accounted for in the relevant models indeed.

~~~
acqq
> I guess that is accounted for in the relevant models indeed.

Yes it is, take a look here how complex it is:

[https://www.earth-syst-sci-
data.net/10/405/2018/essd-10-405-...](https://www.earth-syst-sci-
data.net/10/405/2018/essd-10-405-2018-discussion.html)

And it's not just "models" for the predictions, the data about what happens
from day to day and from year to year are measured constantly, and all give
the numbers that are very clear. CO2 in the atmosphere increases. And it won't
be nice.

To quote one scientist that first didn't believe, but checked the data and now
himself corrects the false claims by those who have some special agendas:

"Of the 7 GtC, which we blow into the atmosphere every year, only 3 remain
there. 2 are absorbed by the ocean and 2 by the forests. This means that in
the atmosphere and in the land biosphere and in the ocean the amount of stored
carbon is increasing. And the source of all this additional carbon is the fact
that we extract loads of fossil carbon from the earth's crust and add it to
the system."

"The system was almost exactly in equilibrium before humans intervened. That
is why the CO2 concentration in the air was almost constant for several
thousand years."

Now it's not, even if the biosphere takes some of CO2 the we extract from the
Earth's crust, still more remains up there and makes the Earth surface warmer.

We measure that year after year already.

Here you can find the graph of the measurements of CO2:

[https://e360.yale.edu/features/how-the-world-passed-a-
carbon...](https://e360.yale.edu/features/how-the-world-passed-a-carbon-
threshold-400ppm-and-why-it-matters)

Yes, there is more CO2 every year, yes, some CO2 remains in biosphere, but no,
there's no balance.

------
sampo
If in high CO2 rice grows 10% better, you can use only 90% of your land for
rice and still get the same amount of rice. And then use the freed 10% of your
land to grow some other, super nutritious plants. Perhaps you end up getting
more food and more nutrients from your land.

~~~
jfnixon
Or you get two crops instead of one during the growing season. And you get
more to eat. If protein is down 10%, but plant growth is up 15%, it would be
possible to eat 10% more. For people getting barely enough food, that might be
a good thing.

------
akavel
The text-only version of the article, thanks to the GDPR:

[https://text.npr.org/s.php?sId=616098095](https://text.npr.org/s.php?sId=616098095)

