Lets assume that rising temperature follows a regular trajectory, and lets assume that there is a one-to-one correlation between temperature rise and its consequences. Such a regular trajectory is unlikely as the combination of growing C02-e, carbon and ice-melt feedbacks, solar cycles and stronger El Niño may join with extreme weather events and global tipping points to speed up this process.
Though we don’t understand many of the complexities, the simplicity of this calculation has a lot to recommend it.
With steady linear growth the earth will be heated to 1oC by 2012, and to 2oC by 2030.
Paleoclimatic evidence shows that for every 1oC rise we should expect a minimum 4-metre rise in sea levels.
We have just calculated that by 2030 the conditions will be in place to guarantee a minimal 8-metre sea level rise. With the usual inertial delays of thirty years or so built into the earth’s system, and applying a regular trajectory for sea levels as we did with temperature, we could be looking at 50cm rise within a decade and a full metre during the next.
During this time large areas of agricultural land will be gradually flooded, in Egypt, Bangladesh, northern China and the Philippines. Florida, Boston and London will be badly affected, as will Melbourne and much of our coastline.
Food production will be lessened as the Himalayan glaciers melt, there will be a lot less to fish and land will be lost to drought and sea. In the same period global population will rise by one billion, most living in cities.
This is a recipe for catastrophe if we dont prepare.
We are fully aware of the refugee crisis that would follow such sea-level rise, and the likelihood that there wuld be war.
However we vary the parameters, this process shows we have run out of time and should prepare now for what cannot be prevented if we wish to preserve a planet similar to that on which civilisation developed and to which life on earth is adapted.
A National Risk Assessment Council is needed to prepare citizens for the changes that are coming, (Source John James (Planet extinction.com))