Aug 10, 2018
California, having lived through unseasonably hot and dry months, is today besieged by rapidly expanding wildfires.
The mid-Atlantic states have been hit by wave after wave of rain, saturating the ground, overflowing river banks, and destroying parts of some towns.
The Upper Peninsula of Michigan and Wisconsin were hit by storms with winds reaching near hurricane strength.
Crops in other parts of the Midwest were scorched, when temperatures ran 20 degrees above normal and the ground, starved for rain, was parched.
All these extreme weather events have one thing in common: they are related in one way or another to the steady rise of global temperatures.
Higher temperatures don’t create the same conditions everywhere – what happens depends also on the underlying conditions of any area, and the vagaries of the way that weather develops across a continent. In areas that tend to be dry anyway – like large parts of California – the increasing heat can dry out vegetation, creating conditions ripe for fire. In areas whose weather is directly affected by the Canadian jet stream, heat can cause large fluctuations in the jet stream, creating rapidly changing bands of weather, dropping monsoons over some areas, and scorching others.
There can be no doubt that temperatures are increasing. Decade after decade, annual measurements have shown the world’s temperature on the rise.
The increase may have been slow, and not very big – only a fraction of a degree in any single year. But the temperatures have been rising for many decades now. The total increase comes to not quite two degrees in the last hundred years.
Two degrees may not sound like much. But two degrees is enough to set California on fire, to send flash floods into Maryland and Pennsylvania, to dry out the Midwest corn crop – not to mention, to melt the polar ice cap and to raise ocean levels.
Two degrees on a thermometer translates into weather extremes and human catastrophe.