"Do you believe in global warming?" is a question I sometimes get asked when I'm guiding on the Fox Glacier.
It's a question I find hard to answer because belief (or non-belief) is not really an appropriate response to this issue. It doesn't matter what I believe! What's important are the facts.
For example, my intuition is that it has been wetter in Fox Glacier so far this summer than it was a year ago. But if I tell you, "I believe it's been wetter this summer", it isn't very confidence inspiring, is it? I really need to answer a much simpler question: "Has it rained more this summer than it did last year?" Then, I can dig out the rainfall records from last summer and compare them to this year. You want the facts, not my opinion.
The problem with global climate is that, although the questions may be simple, finding answers is not. To a non-expert, the facts can be confusing and we may not fully understand the methods by which the data has been obtained. So, when we don't know for sure, and even the experts seem to disagree, we frame our question in terms of belief.
How else can we approach issues when we are not sure of the facts?
Here is Michael Shermer, from Skeptic Magazine, outlining his 10 point "Baloney Detection Kit" to help in precisely such situations.
With the specific issue of climate change there are really two simple questions:
- "Is the Earth's climate changing?"
- "Are humans a causal factor with respect to climate change?"
And the answers to those questions are:
- Yes, definitely. The Earth is getting warmer.
- Yes, probably. Humans are contributing large volumes of greenhouse gases to the atmosphere and this appears to be driving an increase in the earth's average temperature.
Incidentally, I checked the monthly rainfall figures for Fox Glacier.
December 2010: 1016mm *** December 2009: 646mm
J a n u a r y 2011: 596mm *** J a n u a r y 2010: 710mm
This summer total: 1612mm *** Last summer total: 1356mm
So my intuition was correct!