As we near the end of the millenium, a quick review of the last 1000 years of climate seems in order. Now we can't get TOO specific - but climatologists can use things such as tree rings, ice cores, and sediments for indicators about what the climate was like these past 1000 years or more.

There's evidence that the period from around the year 1000 to the year 1300, sometimes called the Warm Medieval Epoch, was - as its name suggests - relatively mild. This may have only been the case around the North Atlantic Ocean, where the Vikings settled Iceland, Greenland, and northern Newfoundland.

By the middle of the 1500s, however, the globe had cooled, perhaps by a degree or two. This cooler period, known as the Little Ice Age, lasted until about the middle of the 1800s. After that, average global temperatures have gone up about a degree and a half, and much of that warming has occurred in just the last 20 years.

We can't say with certainty, but it's likely that, on average, the 1990s was the warmest decade of the last millenium.