Worst for 1,200 years: Western America in historic megadrought

The American west is in its most extreme megadrought for over 1,000 years, and it doesn’t look likely to change soon.

In a study published by the University of California, researchers say current drought conditions which have persisted for the last two decades are the worst on record for the past 1,200 years.

The west is also in its driest 22-year period in known history and climate models suggest it will continue until at least 2030.

To come to their conclusion, more than 1,500 trees were analysed. Tree rings offer plentiful climate information, thicker layers indicate lots of moisture while thinner layers show the trees were under stress.

With the oldest trees analysed growing since the year 800, we know that the current megadrought is of historic proportions.

Megadroughts are prolonged droughts lasting greater than two decades. Previously, natural variability in weather conditions caused droughts, but increasingly human-led warming is causing the issue.

In the study, it is said that anthropogenic-sources of warming have resulted in a 42% increase in drought severity.

Many lakes and reservoirs, including Lake Mead and Lake Powell, are at or nearing record low water levels. Meanwhile, the Californian snowpack is now below-average after one of the driest starts to a year on record followed by a heatwave in February.

The conditions are also contributing to wildfire issues along the west coast which routinely result in millions of dollars of damages.