Sunday, October 30, 2016

Spain Could Turn Into A Desert

The Paris Agreement recently adopted on global warming resolves to keep the increase in global atmospheric temperature to within 1.5 degrees Celsius.  The Mediterranean is warming faster than other parts of the world and is already at 1.3 degrees.  Unless action is taken immediately, which is unlikely, it will hit 2 degrees there (and also throughout the world) in twenty years or so.  And if even the most drastic action isn't taken, the worst case scenario is dire for most the world by the end of the century.

Mediterranean ecosystems will change to a state unprecedented in the past 10,000 years unless temperature rises are held to within 1.5C, say scientists
Southern Spain will be reduced to desert by the end of the century if the current rate of greenhouse gas emissions continue unchecked, researchers have warned.
Anything less than extremely ambitious and politically unlikely carbon emissions cuts will see ecosystems in the Mediterranean change to a state unprecedented in the past 10 millennia, they said.
The study, published in the journal Science, modelled what would happen to vegetation in the Mediterranean basin under four different paths of future carbon emissions, from a business-as-usual scenario at the worst end to keeping temperature rises below the Paris climate deal target of 1.5C at the other.
Temperatures would rise nearly 5C globally under the worst case scenario by 2100, causing deserts to expand northwards across southern Spain and Sicily, and Mediterranean vegetation to replace deciduous forests. 
[....]

They then ran the model to see what would happen to the vegetation in the future, using four different scenarios of warming, three of them taken from the UN’s climate science panel, the IPCC. Only the most stringent cut in emissions – which is roughly equivalent to meeting the Paris aspiration of holding warming to 1.5C – would see ecosystems remain within the limits they experienced in the Holocene.
“The main message is really to maintain at less than 1.5C,” said Guiot. “For that, we need to decrease the emissions of greenhouse gases very quickly, and start the decreasing now, and not by 2020, and to arrive at zero emissions by 2050 and not by the end of the century.”
 This kind of action is not likely so we will have to look forward to some very dire circumstances in the Mediterranean not to mention world wide.