We’re in a carbon drought. That is according to Professor William Happer of Princeton University. The renowned physicist says when it comes to carbon dioxide, there’s more good than bad. He goes on to say most of carbon dioxide’s effect has already happened. He points to the logarithmic dependence of temperature on carbon dioxide levels. Happer says the unique properties of carbon dioxide mean that current levels would need to double for another one-degree increase in temperature and they’d have to double again for another one degree rise.