Gheorghe Curelet-Balan Blog

Sunday, December 10, 2006

What climate catastrophes?

If you are wondering what catastrophes could be caused by global warming, just look at the below picture. All red zones will submerge if the sea level raises with 20 meters as result of the increase in precipitation.

David Archer started his PI lecture with the statement that satellites and weather stations agree that Earth is warmer now with 0.5 degree Celsius since 1960 and the trend is steady upward. The difference is more evident (of around 1 degree Celsius) if we compare today's Earth temperature with that at the beginning of last century.

Here there are some other ideas that I've picked up during the lecture:
Even though the current warming looks like the Medieval warming,
by analysing historic climate change patterns it is estimated that the Earth in the year 2100 will be its warmest in millions of years. As a consequence by year 2300 tundra is lost.

The danger is that once engaged in the warming trend there is no easy way back since some percentage of the CO2 released into atmosphere stays for thousands of years before it is absorbed.
If the current fossil fuel CO2 pollution continues it could look similar with the sudden natural CO2 release in paleocene/eocene. As you can see in this picture the warming recovery took 100,000 years.

The raise of sea level could be caused by the debris rafted by the flow of big ice sheets into the ocean. Since it is not well known how water gets through the ice such events could happen much sooner than expected. Unfortunately we have a big proof of water flowing into the ice in Greenland moulins. The question is if we are today at the beginning of a dejavu scenario of sea level increase.

Then there are methane hydrates that are worse polluters than coal. Unfortunately there is lots of methane hydrates (much more than world's coal) below the sea bed that could be released if the ocean temperature increases.

It looks like the Earth is unforgivable if we are messing up with it.


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