The Long View

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This page is more of a blog post of my thoughts about the key challenges in atmospheric chemistry and its role in climate science. It is by no means exhaustive or even correct, rather opinions of mine formed after discussion with colleagues and reviews of the literature.

Climate change is primarily driven by increases in atmospheric CO₂ concentrations and reducing emissions of CO₂ and ultimately CO₂ concentration is critical to averting severe climate change.

However, changes to the concentrations of other gases and aerosols will also play an important role in future climate and our efforts to prevent severe climate change since these species are often much more efficient per unit mass as climate forcers. Focusing solely on CO₂ could lead to unintended consequences which hinder climate change mitigation efforts.

In my view, four key questions at the intersection of atmospheric composition and climate are:

1. How will (non-CO₂) atmospheric composition change over the course of this century under different societal development scenarios? These sceanrios range from those which simulate extensive efforts to reduce GHGs and improve air pollution to those which assume business-as-usual behaviour.

2. What role will this change in atmospheric composition have on climate? In other words, will these changes exacerbate or oppose CO₂-driven warming?

3. How will proposed climate change mitigation strategies, such as a wide scale tree planting or marine cloud brightening, change atmospheric composition, planetary albedo, and climate?

4. What role will atmospheric composition play in the effectiveness of climate change mitigation strategies?