Having written the first book about global warming 23 long years ago, I’ve watched the issue unfold across decades, continents, and ideologies. I’ve come to earth summits and conferences of the parties from Rio to Kyoto to Copenhagen, and many places in between.

All along, two things have been clear.

One, the scientists who warned us about climate change were absolutely correct—their only mistake, common among scientists, was in being too conservative. So far we’ve raised the temperature of the earth about one degree Celsius, and two decades ago it was hard to believe this would be enough to cause huge damage. But it was. We’ve clearly come out of the Holocene and into something else. Forty percent of the summer sea ice in the Arctic is gone; the ocean is 30 percent more acidic.

There’s nothing theoretical about any of this any more. Since warm air holds more water vapor than cold, the atmosphere is about 4 percent wetter than it used to be, which has loaded the dice for drought and flood. In my home country, 2011 smashed the record for multibillion-dollar weather disasters—and we were hit nowhere near as badly as some. Thailand’s record flooding late in the year did damage equivalent to 18 percent of the country’s gross domestic product (GDP). That’s almost unbelievable.

But it’s not just scientists who have been warning us. Insurance companies—the people in our economy who we ask to analyze risk—have been bellowing in their quiet, actuarial way for years. Here’s Munich Re, the world’s largest insurer, in their 2010 annual report: “The reinsurer has built up the world’s most comprehensive natural catastrophe database, which shows a marked increase in the number of weather-related events. For instance, globally, loss-related floods have more than tripled since 1980, and windstorm natural catastrophes more than doubled, with particularly heavy losses from Atlantic hurricanes. This rise cannot be explained without global warming.” [read complete article at CommonDreams]