A science presenter, writer, speaker & former TV host; author of The Skeptic's Handbook (over 200,000 copies distributed & available in 15 languages).



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Increasing CO2 threatens human nutrition (From the Annals of Hype)

Disaster Disaster! Driving a car in 2014 could one day cause 2 billion people to suffer from zinc and iron deficiencies leaving them anaemic and prone to infection, and causing a loss of 63 million life-years annually. This is brought to you from the Annals of Hyped-Science (formerly known as Nature). A sad day indeed.

It’s true that carbon dioxide is plant fertilizer and increases plant yields, so future crops, grown in a CO2 rich world, may not have exactly the same nutrient profile. Presumably future plants will have slightly more useless starchy carbohydrate. It is a kind of dilution effect at work, where plants keep absorbing the same amount of minerals, but spread them out among more carbohydrate.

Before we hit the panic button, lets look the numbers. The new Myers et al study[1] reports that zinc and iron content of rice may fall by, wait for it, five percent. In wheat the iron content could fall by as much as 10%. But no one who has a choice, eats grains like rice or wheat for their iron and zinc content, since both these are poor sources of both. We’re talking about low grade bulk filler food.

Assuming the […]

CO2 emissions in last 50 years made us $3.5 Trillion wealthier

Millions of people are alive today because the net emissions of carbon dioxide have increased. These extra emissions have provided essential fertilization for crops around the world. Craig Idso has released a new report calculating that the extra value that the rise in CO2 has produced from 1961 – 2011 is equivalent to $3.5 trillion dollars cumulatively. Currently the extra CO2 is worth $160 billion dollars annually. Big-biccies. Projecting forwards, increasing CO2 levels could be worth an extra $9.8 trillion on crop production between now and 2050. Virtually every economic analysis to date does not include the agricultural gains. There are also benefits in health, as warmer winters reduce mortality by more than hotter summers increase deaths. The real economic question then, is “Can we afford to slow CO2 emissions at all?”

While there are negative externalities projected by some climate modelers, their models are unvalidated, proven wrong, and based on unsupported assumptions about clouds and humidity. Compare that to the agricultural gains, which are not just demonstrated in laboratory greenhouses, but confirmed in the field, and with global satellite estimates of increased biomass.

Obviously, the only sensible thing to do at this point is continue our emissions of […]

Plants suck half the CO2 out of the air around them before lunchtime each day

A paper that is nearly 60 years old shows us just how intrinsically important CO2 is to life.

An acre of corn is a living machine drawing CO2 from the air around it. In windless conditions, CO2 concentrations over a cornfield build up each night as CO2 diffuses from higher air and the organic matter and bacteria create CO2 from the soil. A paper by Chapman et al from 1954[1], shows that as soon as the sun comes up, to power-up those dormant photosynthetic cells, the plants rapidly draw down as much CO2 as possible, and when the CO2 levels fall too low, plant growth surely slows.

On a windless day CO2 values rose to 410ppm overnight and fell to 210ppm during the morning.

This graph shows CO2 content of the air over a cornfield on a still day (no wind). Sunrise occurs at 5am and CO2 levels plummet til 8am, reaching their lowest by 1pm, which is nearly half the CO2 concentration of the peak reached overnight. The corn is affecting CO2 levels in air even as high as 150m or 500ft above. These level out by around 8am and only start to increase again, a couple of hours […]