Captain Imperio Answers Your Climate Questions
Q: How does the current temperature compare with past temperatures? A: It’s hot compared to the last five hundred years, and maybe even compared to the last several thousand years. It’s cold compared to most of the last 500 million years . Q: How about CO2? How do current CO2 values compare with those in the past? A: Current values are high compared to most of the last several hundred thousand years (see: here ) but much higher concentrations of CO2 occurred in the past. Before life originated, much of the atmosphere may have been CO2. Values for most of the last 500 million years appear to have been much higher than at present, but considerable uncertainty exists here Q: If it was hotter in the past, and there was a lot more CO2, why should we worry? Is mass extinction a threat? A: Mass extinction is already happening, due to habitat destruction, mostly but not entirely independently of warming. Clearly life can adapt to many temperatures and CO2 concentrations, but we, ...