By Ramin Skibba
Seville and Lisbon (click here) have thrived for more than a thousand years in a temperate climate. But if global warming continues at the current pace, these cities will be in the middle of a desert by the end of the century, climate modelers report on 27 October in Science.
Maintaining the historic ranges of the region’s ecosystems would require limiting warming to just 1.5 ºC, by making substantial cuts to the world’s greenhouse-gas emissions, the analysis concludes. Otherwise, the vegetation and ecosystems of the Mediterranean basin will shift as temperatures rise. Increasing desertification in southern Europe is just one of the changes that would result.
“Everything is moving in parallel. Shrubby vegetation will move into the deciduous forests, while the forests move to higher elevation in the mountains,” says Joel Guiot, a palaeoclimatologist at the European Centre for Geoscience Research and Education in Aix-en-Provence, France, and lead author of the study....
It is a foregone conclusion, a 2 degree Celcius world is dangerous.
..."We are detecting large changes (click here) in climate impacts for a 2C world, and so should take steps to avoid this," said lead editor Dann Mitchell, an assistant professor at the University of Bristol.
The 197-nation Paris climate treaty, inked in 2015, vows to halt warming at "well under" 2 deg C compared to mid-19th century levels, and "pursue efforts" to cap the rise at 1.5 deg C.
UN Secretary-General Antonio Guterres on Thursday said climate change was "the most systemic threat to humankind".
With only one degree of warming so far, Earth has seen a crescendo of droughts, heatwaves, and storms ramped up by rising seas.
Voluntary national pledges made under the Paris pact to cut CO2 emissions, if fulfilled, would yield a 3 deg C world at best.
The treaty also requires that - by the end of the century - humanity stop adding more greenhouse gases to the atmosphere than oceans and forests can absorb, a threshold known as "net zero emissions".
"How fast we get to a 2C world" is critical, Dr Mitchell told AFP. "If it only takes a couple of decades, we will be in trouble because we won't have time to adapt to the climate."...
Example of the danger of 3 degree Celcius rise in temperatures.
