There is broad agreement — except among a small group of political fanatics called “deniers” — that human emissions of carbon dioxide are causing the earth to warm, with lots of nasty consequences. In general, this is perceived as being a future problem; for the time being (according to the common wisdom), the effects of climate change are minor.
I challenge that notion. Climate change is already costing us a lot of money. Here’s a long and tedious report assessing the current costs of climate change as of 2010. A more manageable summary of that report can be found here. The overall conclusion is that climate change is already costing about $1.2 trillion per year globally, or about 1.6% of global GDP.
We normally attribute the costs of climate change to things like sea level rise and hurricanes, but the costs extend in many different ways. A good example of this was my recent experience with a one-two punch of record-setting snowfall and record-setting low temperatures, described in great detail here. The total impact of this on me was $2000 in out-of-pocket costs and about two weeks of my life devoted to dealing with the weather. As you might imagine, this comprises a huge impact.
Can we point the finger of blame for all this on climate change? Not explicitly. One of the fundamental rules of climatology is that any individual weather event cannot be ascribed to climate change. Climate is a statistical concept, describing the overall average weather over an extended period.
Think of it this way: we had an economic crash in 2008. Millions of people lost their jobs and/or their homes as a result of that crash. Yet it’s difficult to blame the crash for the suffering of any individual. Perhaps they lost their job because they weren’t working hard enough. Perhaps they lost their house due to poort financial planning. You can only assign blame for all the suffering in a large statistical sense.
In the same fashion, I can’t honestly blame my problems on climate change. However, we know that this particular event was quite abnormal: both the amount of snowfall (14”) and the lowest temperature (3ºF) were records for my neighborhood. Last winter, for example, we had only a couple of snowfalls, they were only about one or two inches, and the temperature rarely fell below 25ºF.
The physical reason for the extreme weather I experienced was a pronounced “kink” in the jet stream, bringing frigid Arctic air much further south than it usually goes. Indeed, the Arctic itself is experiencing abnormally high temperatures, largely because its cold air is moving south and warm air from the south is moving to the Arctic. This kink in the jet stream, in turn, is caused by dramatic changes in the general circulation of the atmosphere that are, in turn, caused by climate change. The chain of cause and effect is long, and there are uncertainties in each of those steps, but the connection certainly makes sense.
So while I cannot convict climate change of responsibility for my troubles, it is certainly the Prime Suspect. More important, this is the kind of thing that we can be certain will be happening to lots of people in coming years. Perhaps for you it will be a hurricane, or a tornado, or floods, or a drought, or sea level rise. But the odds are high that, one way or another, climate change will be giving you grief sometime in the next decade or two.