Scott Adams says the observation that “carbon dioxide is plant food” is a terrible argument– an “embarrassing opinion”– for AGCC skepticism.
He’s wrong. Here’s why:
When plants “eat” CO2 they take it out of the air and turn it into plant matter. Even if carbon dioxide raises the climate’s temperature as the AGCC activists claim, once a plant removes it from the air, it isn’t available in the atmosphere to raise the temperature anymore. That’s how “eating” something works. It is removed from availability in one form (in this case, atmospheric gas) and turned into a different form (leaves, wood, flowers, stalks, roots, seeds, fruit, etc.).
And, yes, each individual plant might be able to only use a limited amount of carbon dioxide, but plants reproduce. If you improve their growing conditions with more “food” (and sufficient light), they can reproduce more. If you’ve ever had an aquarium or a pond experience an algae bloom you’ve seen the conditions result in more plantlife. And one of the most effective ways to end the algae bloom is to add other plants which will use up the “plant food” available in the water until it is reduced to a level where it can’t encourage excess plant growth.
But to say that the addition of CO2 will raise the temperature and kill the plants so that they can no longer “eat” the CO2 is overlooking the main effect of plants taking CO2 from the air and using it to make more plant matter. More plants = less CO2 in the atmosphere available to warm the climate.
Now, when those plants rot or burn, that CO2 will be released into the air again. But, more CO2 could result in more plant mass overall, trapping the CO2 in a form which can’t contribute to “climate change” at least for a time. Coal is plant matter, made of atmospheric CO2 removed from the air long ago (~359 to 299 million years ago, in fact) and stored in a fairly stable form. Once that carbon dioxide was in the form of plant matter– living plants or coal– it couldn’t help heat the world until it burned.
Sometimes a person tries so hard to look unbiased and “scientific” that they fall into a reality trap. This seems to be one of those times for Scott Adams.