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Does climate change cause a drought? Does it cause a famine?

  • 08 Aug 2011, 13:50
  • Christian Hunt

It's worth reading a piece discussing the Somalian drought and accompanying famine by Chris Funk, a researcher at the University of California, which neatly illustrates how the 'did climate change cause extreme weather event X' question isn't particularly helpful.

Last year, his team essentially predicted the drought in Horn of Africa which has led to a famine. And there's a link to climate change. But note the different components to the analysis:

Last summer, our group was meeting when a La Niña weather system was forecast. We knew that such an event could bring trouble, and we issued an alert that East Africa might experience severe droughts.

We based this conclusion on information from three sources. First, we knew that La Niña events are commonly associated with weakened rains in the Horn of Africa from October to December.

Second, from work on the ground, we knew that persistent poor rains at the end of the past decade, combined with high food prices, had weakened the population's resilience to food emergencies.

And third, research has linked warming in the Indian Ocean as a result of climate change to drying of March-to-June rains in East Africa. This warming has intensified the negative impact of La Niña events; it was the chance that both the autumn and spring rainy seasons could be affected, back to back, that really concerned us.

So according to Funk, here's a social problem (famine), driven by an extreme weather event (drought), occurring in a particular context of poor rains and high food prices. The drought is a result of changes in a natural weather system (La Nina), which may have been dangerously intensified by climate change.

You couldn't say that climate change 'caused' the drought or the famine. But you also couldn't say that it was unrelated. And that highlights a basic problem with the way we discuss causation, climate change, and extreme weather. There's a logical hiccup in saying that because we can't pinpoint climate change as 'the' cause for a specific extreme weather, there is no link.

It's going to be necessary to point this mistake out where it occurs, because the things which make it hard to predict extreme weather in advance - the difficulty of doing regional climate change predictions, and the difficulty of short term weather forecasting of specifics compared with long term climate forecasting of averages - aren't going to change any time soon.

You can donate to the Disasters Emergency Committee, which is co-ordinating funding to aid relief in the Horn of Africa, here.

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