|2011-06-08 20:04:25||Basic rebuttal 184: "There's no link between global warming and extreme weather"|
Whenever there is an extreme weather event, such as a flood or drought, people ask whether that event was caused by global warming. Unfortunately, there is no straightforward answer to this question. Weather is highly variable and extreme weather events have always happened. Detecting trends takes time, particularly when observational records are rare or even missing in certain regions. An increase in extreme weather is expected with global warming because rising temperatures affect weather parameters in several ways. Changes in the frequency of extreme events coinciding with global warming have already been observed, and there is increasing evidence that some of these changes are caused by the impacts of human activities on the climate.
How global warming affects weather parameters
Rising temperatures can have several effects on the factors involved in weather. For example:
These changes don't automatically generate extreme weather events but they change the odds that such events will take place. It is equivalent to the loading of dice, leading to one side being heavier, so that a certain outcome becomes more likely. In the context of global warming, this means that rising temperatures increase the odds of extreme events occurring.
Changes in extreme weather events are already being observed
In the US, the Global Changes Research Program published a report in 2009 entitled Global Climate Change Impacts in the US. The National Climate Change chapter reports the following findings for recent decades:
Similarly, Australia has seen the odds of both heavy rainfalls and droughts increase, and similar patterns are being observed worldwide, coinciding with rising temperatures over the past 50 years.
In conclusion, although it isn't possible to state that global warming is causing a particular extreme event, it is wrong to say that global warming has no effect on the weather. Rising air and sea temperatures have a number of effects on the water cycle, and this increases the odds for more extreme weather events.
"Changes in the frequency of extreme events coinciding with global warming have already been observed,"
"Rising temperatures can have several effects on the factors involved in weather. For example:" (since this isn't a complete list)
"These changes don't automatically generate extreme weather events, but they change the odds..."
Doesn't rolling of the dice become more predictable if you load them? i.e. the loaded side is more likely to come up. I'd revise to say "loading of dice, leading to one side being heavier, so that a certain outcome becomes more likely."
Looks good otherwise.
Thanks Dana, I've updated it.