Ozone alert: it's either too much or too little

Raes, who is studying the effect of ozone on rice, corn, wheat and soybean, says that ozone smog's effect on agriculture may well be far worse than global warming.

Even so, ozone and global warming are linked, as both are caused by the fossil fuels and both are cross-border problems.

Countries such as the US which complain that controls on carbon dioxide cost their economy too much should be told that by cleaning up fossil-generated CO2, they also help tackle ozone damage, says Raes.

“What's good for the climate is also good for the air,” he says.