I was contemplating writing a post about a discussion I had on Twitter regarding whether or not we should focus on adaptation while developing technology, but I don’t really have the time now. The one comment I will make is that technology development is of course a crucial part of future progress. However, if we do have some desire to replace fossil fuels with some alternative, then that would seem extremely difficult (almost impossible, one might say) if we choose not to incentivise a change to alternatives, and if the cost of using fossils fuels doesn’t reflect the true cost of their use.
What I wanted to post (as a reminder to some, maybe) is that cumulative emissions matter. As you can see in the figure below (from the IPCC’s AR5 SPM) how much we will warm largely depends on the total amount of CO2 we emit (not quite, but reasonably close). Although there isn’t really some well-defined threshold above which it will be catastrophic and below which it will be fine, the figure below does illustrate that if we do want to avoid a certain amount of future warming, we have to constrain our total future emissions. Therefore, the more we emit today, the faster we will have to reduce our emissions in the future.
I am not really trying to draw any actual conclusions from this, other than to point out that our cumulative emissions do matter when it comes to how much warming we will experience. I will, however, also add the following figure that Mark Maslin has been promoting on Twitter. It shows that, currently, we are following what many would regard as a high emission pathway. So, total emissions matter and we’re currently emitting CO2 at about the fastest rate we’ve considered realistic. Some might think that this would suggest that we should be putting some serious effort into finding ways to reduce our emissions so as to avoid our cumulative emissions rising to the point where significant warming becomes unavoidable. Others, it would seem, disagree.