USA suffering from a megadrought

The western USA is experiencing this event. A megadrought is where a drought lasts for many decades without any easing. There have been 4 previous megadroughts in the last 1200 years which have affected the USA and the evidence for these has been discovered by dendrochronologists. Lake deposits have also been analysed. The evidence shows changes in soil moisture over time - indicating drought conditions.

Soil moisture records from the years 2000-2018 already indicate that the current drought conditions are worse than 3 of the 4 historic droughts recorded over the last 1200 years. Whilst climate change has been suggested as a cause, the natural events of El Niño and La Niña are most likely to blame. The main effects seen in recent times have included increased wildfire events and the reduction in size of Lake Powell and Lake Mead.

For more information on this event check out the following report:

https://www.bbc.co.uk/news/science-environment-52312260