A volcanic eruption in 1815 proved even small changes in climate have disastrous global results

This is not the first time in recent history that humanity has had to deal with a dramatic shift in the climate. To get a glimpse of the political and economic effects climate change might bring, we don’t need climate-modeling systems to look to the future—we need to go back 200 years in the past.

Donald Trump’s ascent to the US presidency brings with it a renewed string of flagrant instances of global-warming denialism. But science has already spoken: A difference of just a few degrees in average global temperatures is associated with a number of far-reaching effects, such as food shortages, political unrest, mass migration, and a more rapid spread of diseases.

How do we know? Well, that’s what happened last time…

Europe faces droughts, floods and storms as climate change accelerates

Europe’s Atlantic-facing countries will suffer heavier rainfalls, greater flood risk, more severe storm damage and an increase in “multiple climatic hazards”, according to the most comprehensive study of Europe’s vulnerability to climate change yet.

Temperatures in mountain ranges such as the Alps and the Pyrenees are predicted to soar to glacier-melting levels, while the Mediterranean faces a “drastic” increase in heat extremes, droughts, crop failure and forest fires.

Europe and the entire northern hemisphere are warming at a quicker pace than elsewhere, to the extent that tropical diseases such as West Nile fever are expected to spread across northern France by mid-century.

Hans-Martin Füssel, one of the lead authors of the European Environment Agency report, said that scientific evidence was pointing increasingly…