Image Credit: NASA
We keep seeing pictures of a forlorn polar bear on a melting ice floe and climatologists warning that sea levels could rise as much as ten feet. The industrial revolution began in the early 1800s, so skepticism about such statements is warranted. Why will we see such climate change tomorrow that we have not seen to date?
Certainly most people in the U.S. will disagree with NOAA: Sixth Warmest February in Combined Global Surface Temperature. The press release says the global average was 1.35 degrees F above average, although it admits the U.S., Mexico, Europe, and Russia had much cooler temperatures than typical. Alaska and Canada were notably warmer than normal. A strong El Nino continued to raise sea surface temperatures by more than 2.7 degrees F.
Climate Change: Sea Level explains that seal levels are rising from two phenomena: a) the melting of ice sheets and glaciers on land, b) expansion of water due to temperature. The author, LuAnn Dahlman, cautions that even a small rise has large impacts on beaches and flat land, since an inch in elevation can correspond to several feet.
There are charts with combined global average sea levels, but I'm somewhat skeptical of the data aggregation. Sometimes simpler data is better. The chart below shows the water levels from The Battery, on the southern shoreline of Manhattan Island. The trend seems unmistakable - that sea level is rising. Accurate satellite-based altimeters indicate that the rise is about one and a quarter inches per decade.
Image Credit: NOAA, ClimateWatch Magazine
State of the Climate, just released by the Government of Australia. Sea levels in Australia "since 1993 levels have risen 7-10mm per year in the north and west, and 1.5-3mm in the south and east." (10 mm = 0.394 inches).
I like the Australian report's conclusion - "It is very likely that human activities have caused most of the global warming observed since 1950." Science cannot prove a one-to-one correlation, and at the present time, that is the most accurate statement that can be made. But when the National Hurricane Center places my locale as possible landfall, I evacuate before the storm hits.
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