The dangers of CFCs

This weekend Elli and I went to the Ontario Science Centre.  We visited a number of interesting exhibits and had a good time but there were a few that really illustrated how science exhibits need regular updating or they risk delivering entirely the wrong message.

The particular one I have issues with is the exhibit about CFCs and ozone depletion.  The exhibit ended with a note that Canada was planning on eliminating CFC usage by 1995 so I think we can peg its creation time at around 1990 without going too far wrong.  The exhibit talked about the size of the ozone hole, talked about the future of the earth where the ozone layer was very much depleted and deplored the 'current' use of CFCs in refrigeration.  The trouble with all this is that the problem is being presented as a current issue when CFCs are really a solved problem.  The ozone hole over the Antarctic is not gone, but it is no longer growing and there is good reason to think that since CFCs have been mostly eliminated the ozone hole will shrink and go away.  These developments are pretty important in understanding CFCs and ozone depletion of course - the exhibit very much makes it sound like finding ways to eliminate CFCs is a real, current environmental hot topic rather than a success story.  We have not yet repaired the damage done by our use of CFCs but we have successfully turned a major threat and environmental mess into a story of how the entire world can change its ways when confronted with an environmental necessity.

There was also an exhibit on global warming that looked like it dated from around the same time as the CFC one.  Again, knowing the history of the global warming debate is useful but it is pretty unprofessional to have data on something that changes so quickly be 20 years out of date.  The models that were being used then are hopelessly out of date (or simply wrong) and much of the projections and 'what if' scenarios described are just as much incorrect.  There is also a lot of extreme alarmism in the exhibit that you can still find in the current media but which just isn't well supported by the science.  Global warming is a reality but apocalyptic predictions aren't supported by strong evidence.

Of course there were lots of things in the Science Centre that I heartily approved of.  A giant lifesize exhibit of a replica of the heart of a blue whale was tremendous and very exciting for Elli - crawling around inside the whale's heart was a ton of fun for her and gave her an idea of just how immense whales are that other measures simply would not accomplish.  A fan blowing air straight up keeping a ball supported on the column of air (Video here) is a wonderful illustration of complex scientific ideas that have important real world implications.  When intending to portray contentious scientific ideas it is critical that information be kept relatively up to date.  Obviously the Science Centre isn't going to be able to maintain constantly changing exhibits to be completely current with the cutting edge of science but when talking about things like global warming or the ozone layer having exhibits 20 years old is really dropping the ball on educating the average person.