The Brazilian scientist is arguing that the “heat island” and air pollution created by metro Rio has led to more lightning strikes. The British scientist said that although the theory is plausible, a great many factors influence weather.
To assess the theory, I suppose historical data would need to be looked at, especially comparing change in the city’s weather with regard to change in the weather of the surrounding area. I wonder if such a study has been done for any large urban area?
Put a large statue with metal reinforcements on top of a tall mountain. Stir gently. Wait for lightning. Not a surprise. From what I’ve read some of the fiercest lightning in the U.S. happens in the dry, flat, relatively deserted Great Plains. It’s called weather.
The collision between cold air and hot moist air is what causes the terrible storms on the US plains. That is basically the same mechanism that the Brazilian researcher described.
The scientist’s claim is unusual because he said the micro-climate of a city will produce this effect.