I was enchanted by Twitter on the opening day of Brainstorm Green. By creating what’s called a hashtag for the event – in this case, #FortuneGreen – those of us who organized the Fortune conference about business and the environment encouraged people at the event to tweet about it. And we made it easy for anyone to follow or search for a stream of tweets from the event.

So I opened my laptop and, in real time, read dispatches from the event: What was being said, what others thought about about what was being said, big ideas, trivial observations, critiques of our speaker, links to photos from the scene–all in 140 characters or less, the limit on the size of messages that can flow through Twitter. (For an explanation of Twitter, see this.) While the size of each message is limited, there’s no limit on the number of 140-character dispatches you can send. So people, including me, were sending out dozens of tweets per hour.

By searching Twitter (at http://search.twitter.com/) for Tweets containing #FortuneGreen—are you still with me here?—anyone can see everything that was said about the event. Kind of fun. Some examples from today’s session, and I won’t try to translate all the shorthand now:

oppgreen: http://twitpic.com/3sv27 - Cowboy Clinton at #fortunegreen today…check out his cowboy boots…yeehaw! patrickdo: @mlamonica thanks for the link, great story on Bill Clinton at #fortunegreen mlamonica: Green business is key to tackling climate change, says Bill Clinton. link to full story this time http://t.cnet.com/4g #fortunegreen DavidSwardlick: Pres. Clinton - the only morally accepable way to controll population in the world is to help get all the girls into schools #FortuneGreen Milieunet: RT @greenwombat: Clinton: Arizona & Nevada: “Those are two of the places it would be easiest to make energy independent.” #FortuneGreen

You get the idea.

Anyway, I was tweeting merrily along after moderating a panel on climate change politics in Washington when I sent out the following:

MarcGunther: EDF’s Fred Krupp, NRG’s David Crane, Duke’s Jim Rogers say, give away 100% of permits under cap and trade at first #FortuneGreen

During my panel, I had understood Fred Krupp of the Environmental Defense Fund, CEO David Crane of NRG Energy and Jim Rogers, the CEO of Duke Energy, who all belong to the U.S. Climate Action Partnership, to say that all of the allowances under a cap-and-trade program for carbon emissions should initially be given away. The question of whether to give away or auction those allowances—essentially, permits to pollute—is a contentious one, for reasons not worth going into here. To my surprise, my tweet set off a bit of a storm in the world of energy and environmental bloggers, including some not at the event.

My tweet turned out to be the result of a miscommunication or misunderstanding on my part. Of course, since I was reporting live during the event, I didn’t bother to check my facts. I don’t blame Twitter for that. That was my fault.

But I learned two lessons that would have been obvious had I done a little more thinking and a little less tweeting. Lesson No. 1 is this: Trying to cover an event live on Twitter—especially if you are a participant, as I was—doesn’t allow time to check facts or seek out an alternative point of view or think for more than a few seconds about what to say. There’s not enough time to do anything but tweet. In fact, it’s hard just to tweet and pay attention. You’re multitasking. It’s closer to court stenography or simultaneous translation than to real journalism, which requires sifting and thinking. Or at least it should.

Lesson No. 2: There’s not much you can do when you make a mistake on Twitter, particularly if you are dealing with a complex subject. After trading emails with bloggers, NRDC and EDF, I got the following from Dave Hawkins, NRDC’s leading climate expert, who was with us at Brainstorm Green:

What USCAP recommends is that nearly all allocations go, not to emitters, but for consumer rebates/dividends, low-carbon technology, efficiency, low–income protection, adaptation, and international engagement. That includes initial allocations to local distribution companies, with a requirement that the value be passed through to customers and/or invested in efficiency…. You asked about NRDC’s position on allowance distribution. It is set forth in the attached Cap 2.0 proposal and we believe it is consistent with the USCAP Blueprint. It is on the web at http://www.nrdc.org/globalWarming/cap2.0/files/synthesis.pdf

As you can see from figures 2 and 3 of the document, allowance value is focused on clean and advanced energy deployment, efficiency, and consumer dividends from the start and after 15 years all value would go back to consumers as dividends. Of the estimated $100 billion annual value at the start of the program about $8.9 billion is proposed for distribution to energy-intensive industry to prevent off-shoring of production and emissions from these industries. This gets phased down over the initial 15 years of the program.

In 2012 more than $51 billion per year would go directly for efficiency and low-carbon energy RD&D and deployment, with more of the remainder going to consumer rebates and dividends, adaptation, forestry and agriculture incentives, and international engagement.

Try saying that in 140 characters. Even if I could, it would now be impossible to reaggregate the audience that read the original mistaken tweet. All I can do now is send out a tweet about this blogpost—my best effort to correct the mistake.

The real mistake, though, is trying to cover a story in little live bursts. You can’t concentrate, you can’t think, you can’t convey a complex idea, you can’t persuade or explain. That’s why Twitter is bad for journalism–or, more specifically, it is not the right vehicle within which to do journalism.

Twitter will good for journalism in other ways. It’s an effective way to point other people to content on the web. By following others’ tweets, I’ve discovered blogs or stories I would otherwise have missed. I’ve quickly collected several hundred “followers” in just a few weeks, so I can tell about what I’m writing or reading.

Twitter’s valuable in other ways, too. It’s a real-time window into what people are doing and thinking and talking about. It has enormous potential, already demonstrated, as an organizing tool. Anyone in the communications business probably ought to play around with Twitter and other social media like Facebook.

But I had a brief chat with Peter Darbee, the CEO of PG&E Corp., during Brainstorm Green that has stuck in my mind longer than any tweet. He told me that he’s going to cut back on some of his day-to-day work so that he can carve out a couple of hours every day for thinking. Imagine that. Just thinking–no phone, email, meetings or,presumably, tweets. I can’t remember the last time I spent 15 minutes thinking, unless you count time I spend running. Something’s lost because of all the attention we devote to Gmail and blogs and Facebook and Twitter. As Joni Mitchell put it, “don’t it always seem to go that you don’t know what you got till it’s gone.”