As symptoms of global warming are already affecting regions vulnerable to minute climate changes, how long might such effects last? "David Archer, an oceanographer and climate modeler at the University of Chicago, sometimes puts it thus; 'global warming is essentially forever.' Until now, our collective view of future warming has typically ended at 2100 AD, as if it were the edge of a world beyond which we dare not sail. ... But if the world continues to exist beyond 2100 AD, then what happens after global warming?"