Answer: deforestation
Explanation:Deserts are expanding – every year they grow by an area around the size of Ireland. But it's not a natural process; it's manmade. Overgrazing, increasing agriculture, deforestation and a growing use of water are eroding the land.
After the collapse the Pope became isolated in rome and bishops started to operate on their own. It also resulted in a combination of secular and ecclesiastical activities and often the secular ones gained an upper hand.
Hope I helped!!!
They invested in a lot of human capital and fortified their military.
