The little house at the end of a pier in Crissy Field is called a tide house, because equipment inside measures the daily rise and fall of the tide it's been doing that for 155 years.
"Well this particular station is amazing. It's been measuring continuously since 1854," said National Oceanic and Atmospheric Administration scientist Stephen Gill.
Gill says it's the oldest tidal gauge in the western hemisphere. It's had a couple upgrades over the years.
Its original purpose was to help ships safely navigate the bay, but its data is now invaluable to climate researchers, because the gauge also monitors sea levels.
"The sea level has been rising since 1900 about two millimeters per year," said Gill.
That's about eight inches over the last 100 years. Combined with data from other gauges around the world, Gill says it helps shows a sea level rise of two millimeters a year globally as well and now satellite data is monitoring the rising sea as well.
"That system is suggesting a three millimeter per year rise and its sort of implying that over the last 15 years there's been an acceleration," said Gill.
Berkeley-based explorer Dennis Schmidt doesn't need gauges to know the earth is warming.
He is credited with discovering the earth's newest island, revealed in eastern Greenland in 2005 with the retreat of an ice shelf.
He knew the area from living among the Eskimos for years and he named it "Warming Island" in the Eskimo dialect of the region.
This summer, he was in the eastern Siberian Sea for the first time in about 40 years and he said the ice is gone and polar bears are stranded on an island.
"Eventually starvation pushes them out to sea to try to find ice to work from, but there is no ice now so some of these bears we saw swimming past our boat, very sad to see them swimming past, knowing that they were swimming into nowhere," said Schmidt.
Schmidt is not following developments at the Copenhagen Climate Conference, leaving politics to the politicians.