Is more carbon dioxide in the atmosphere bad for the earth and for the species that live on it? Hard to understand how anything is bad for the earth as a system, really only the second part of the question that matters–what optimizes conditions for all life on earth, including humans. Carbon dioxide is a critical component for plant growth, it is a key part of photosynthesis. And it turns out that the increase in CO2 in the atmosphere over recent decades, whatever the cause of that increase, has in fact likely led to an increase in plant productivity, providing more food for various life forms, such as animals, including humans.
If you believe, as I do, that it is important to assess the benefits and costs of any regulatory action, including actions which supposedly would influence the level of CO2 in the air and climate more generally, than those benefits of higher CO2 levels should be included in the analysis. This article makes that point and suggests that for humans, more CO2 and a warmer climate are good things. (AJES Article) At an extreme, imagine what life will be like when the next ice age arrives–will living in Toronto be even possible when it is covered by an ice sheet? Cold is a much bigger killer than warmth. Using real data, there is no increase in extreme weather events connected with either warming or higher CO2 levels. When the cold returns, you will see some really extreme weather.
