This week’s column is not an argument against optimism.

I don’t mind happy talk when there’s reason for it. For many meeting professionals, 2010 closed on a positive note, and I’m not too worried that this week’s headlines will bring news of the next economic crunch.

But one of the most important lessons of the Crash of 2008 was the industry’s deep vulnerability to issues that may be lurking just beyond our view, any one of which could rise up overnight to drive a spike through the meetings economy. I don’t think it’s a lesson we’ve learned particularly well—which means we’re at risk of repeating an economic crisis that we hoped we had put behind us.

Here are five sleeper issues that could shape the industry’s outlook for 2011 in ways that some of us would rather not imagine.

1. More Talk than Action: The steady drumbeat from industry research tells us that the turnaround has arrived. But at every meetings event I attend, I hear that the brave words have yet to translate into significant new spending. Industry leaders are speaking optimistically but spending cautiously. The result: Enough good people are still hungry that everyone else is still nervous.

2. Currencies in Doubt: Last month, a colleague in Geneva told me that Swiss investors are losing confidence in the Euro—and the U.S. dollar. If currencies shift wildly, the underlying value behind any meeting contract will be thrown into doubt.

3. Airlines on the Edge: Start this story wherever you want—with weather disruptions, new surcharges, or the consumer revolt against invasive security measures. Airlines are still a weak link in the meetings supply chain, placing too many meetings too seriously at risk.

4. Weather and Climate: Flooding in Australia. Drought in the Middle East with a record wildfire in Israel. Snowstorms beyond Europe’s (admittedly feeble) ability to cope. And the worst firestorm of all: a political culture in the U.S. that treats global warming as a myth. It’s still tough to link any single weather event to climate change, but meetings infrastructure and destinations are in trouble until communities begin to adapt and commit to drastic carbon cuts.

5. Fuel prices: If the economy does continue to improve, watch for rising demand to feed higher fuel prices. Oil hit a record $147 per barrel before the Crash of 2008, with at least one economist blaming oil prices for the crash itself. The theory of peak oil tells us that pattern will repeat until we can beat our society’s addiction to a declining resource.

You should still seize the moment while the meetings business is picking up. But we can all take this opportunity to build resilience where we can, so that we’re better prepared for the next unexpected bump in the road. If you make 2011 a busy and prosperous year, but pay attention to the areas where your business is vulnerable, you’ll be doing your part to put some substance behind all of that happy talk.

Mitchell Beer, CMM, is president of The Conference Publishers Inc., (http://www.theconferencepublishers.com/) Ottawa, one of the world’s leading specialists in capturing and repurposing conference content. Beer blogs at http://theconferencepublishers.com/blog. Send comments, facts, arguments, or column ideas to mitchell@theconferencepublishers.com.