There’s no precedent in at least five centuries for how hot and dry the West has been in the last two decades, new research asserts using analysis of tree rings. The study, published in late January, adds to an ever-growing slew of research that suggests human-caused climate change is warming the earth in ways never seen before. It furthers other research like one study, published last year, that showed the West’s conditions over the last 20 years are the driest in 1,200 years because of climate change.