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
. 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.