Here are the first five of my “Top 10 climate stories of 2006,” in no particular order.

National Academy hockey stick report: I’m not sure if this helped or hurt the cause, but it did confirm what many scientists already thought: it’s hard to figure out the temperature of the earth 1,000 years ago. The IPCC’s 2001 report said there was a 3 in 4 chance that the 1990s were the warmest decade, and 1998 the warmest year, of the last 1,000. According to the academy report, subsequent research suggests it’s really a 50-50 proposition. In the end, we just don’t know whether it was hotter 1,000 years ago or not. None of that, of course, affects our conclusion that humans are warming the climate.

The CCSP temperature trend report: The Bush Administration says we need to study climate change before taking action. To that end, they devised the U.S. Climate Change Science Program (CCSP), which was tasked with producing assessments of our knowledge of climate change. Their first report, “Temperature Trends in the Lower Atmosphere: Steps for Understanding and Reconciling Differences,” was published in 2006. It is a tour de force summary of all of the evidence that the earth is warming. It concluded that “the evidence continues to support a substantial human impact on global temperature increases.” It sets the stage for what is guaranteed to be one of the bombshells of 2007: the publication of the IPCC’s Fourth Assessment Report.

Hurricane wars: Is global warming making hurricanes worse? The scientific community is split on this question, but — let’s face it — hurricanes scare the sh*t out of most people. The mere possibility that we are causing more massive storms has kept the issue of global warming in the news and ratcheted up people’s worry level.

The return of Al Gore: His movie, An Inconvenient Truth, was a cultural bombshell. Believe it or not, love him or hate him, everyone was talking about it. It kept the issue in the news — the Bush administration’s worst nightmare. And it transformed Al Gore from Democratic loser to legitimate presidential (and Oscar) contender.

Jim Hansen, unleashed!: In early 2006, a young political appointee, George Deutsch, tried to stop Jim Hansen from giving an interview to NPR. Within a few days, George had learned an important lesson: don’t mess with someone who has The New York Times on speed dial. Almost immediately, other government scientists came forward to say they too had been muzzled. Together, they painted a picture of an administration that tries to bury undesirable science. Look for Congressional hearings on the administration’s suppression of science early next year.

To be continued …