To the editor:
David Suzuki is mistaken to say that my position that “CO2 is harmless plant food,” is “anti-climate-science.”
It is, in fact, solid science.
Carbon dioxide (CO2) is the stuff of life, an essential reactant in plant photosynthesis on which all life on Earth depends.
That’s why commercial greenhouse operators routinely run their internal atmospheres at up to 1,500 parts per million (ppm) CO2 concentration. Plants inside grow far more efficiently than at the 400 ppm in the outside atmosphere.
Climate Change Reconsidered II: Biological Impacts, a report from the Nongovernmental International Panel on Climate Change, cites over 1,000 peer-reviewed studies that document rising productivity of forests and grasslands as CO2 levels have increased, not just in recent decades, but in past centuries.
Increasing CO2 levels pose no direct hazard to human health. In fact, CO2 concentrations in submarines can reach levels well above 10,000 ppm, 25 times current atmospheric levels, with no harmful effects on the crew.
Suzuki is also wrong to write that I doubt “the existence of human-caused climate change altogether.”
Humans have an impact on climate when we replace a forest with a parking lot and other land use changes. And, we probably do impact climate to some extent due to our CO2 emissions. However, no one knows the degree to which this occurs, let alone if it is dangerous.
This is why the group I lead, the International Climate Science Coalition, advocates dedicating most climate finance to helping vulnerable people adapt to climate change, no matter the cause.
Suzuki asserts that misinformation muddying the waters of the climate debate is “unconscionable.”
Talk about the pot calling the kettle black.
Tom Harris, B. Eng., M. Eng. (Mech.)
International Climate Science Coalition (ICSC)
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