You can have too much of a good thing

Water is truly the stuff of life. Each living thing needs it; all life arose from oceans, which still provide a huge amount of our food. Fresh water is like gold, a resource we struggle to conserve and keep clean, even as corporations sell overpriced tap water with imagery of pure glacial springs.

So how could water itself be pollution, if it’s something we all need? Is it possible to have too much of a good thing? To answer that, just ask my friends whose pipes burst, causing destruction and disruption. Ask someone who lost a loved one to a tsunami, or their farm to a flood. Ask a person being waterboarded (in between questions about if they are, or have ever been, an Al Qaida member) how they feel about the water of life which is threatening to choke the life out of them. Ask a citizen of a low-lying island whose very nation may soon pass below rising seas forever.

Wait, are those chemtrails?

So yes, you can have too much of a good thing, even water. And the same is true of carbon dioxide (CO2). As a Climate Reality presenter, I help people understand issues around global warming and climate change. But I repeatedly encounter an odd line of climate denial based around the assertion that CO2 is “plant food”, a healthy natural substance we all exhale, therefore can’t possibly be considered pollution, and would be ridiculous to tax with carbon pricing. Should we bill ourselves for breathing? Do we want to starve plants of their food?

Of course, this is a facetious line of reasoning. Climate scientists, and Climate Reality presenters, know quite well the role of CO2 in natural cycles. In fact, the charts of atmospheric CO2 levels we display, like the one in Al Gore’s Oscar-winning “An Inconvenient Truth”, show CO2 fluctuating up and down yearly, due to higher uptake when the northern hemisphere (which has more land mass) has summer. We all learned about photosynthesis in grade school, after all. Yet climate deniers act like this is some revelation, some basic fact we totally overlooked. Nope, not the case!

It is certainly true that CO2 is one of the ingredients plants use to grow. Farmers even pump extra CO2 into greenhouses, to grow flowers or vegetables faster. So pumping extra fossil CO2 into the atmosphere must help, too, right?

Wrong. Plants need water, sun, soil and CO2 to grow. In a greenhouse, plants are given extra of all four, including CO2. But in nature, the amount of sun, soil, and water are constant, or even diminishing, so extra CO2 can’t help forests or crops grow better. In fact, open-air studies show higher atmospheric CO2 helps pests and weakens crops’ natural defenses. This means CO2 itself threatens our food supply, and that’s before we look at the higher temperatures, drought, fires and flooding caused by increasing greenhouse gases like CO2.  

There is no question: without atmospheric CO2, plants could not grow and our world would freeze. But that doesn’t mean more is better; having boosted the amount of atmospheric CO2 over the past 2 centuries from 280 to 400 parts per million, higher than ever before in human history, cannot fail to have significant effects. It’s a huge, uncontrolled, risky and irreversible experiment, one we must curtail as soon as possible.

Published as my Root Issues column in the Barrie Examiner as "Extra CO2 isn't what our planet needs"

Erich Jacoby-Hawkins is a director of Living Green and the Robert Schalkenbach Foundation.