Nightly News | July 05, 2012
>>> now to the west from montana to new mexico. record-setting wildfires are charring mountains, valleys, and houses. nearly 1,000 homes have been destroyed already this fire season. firefighters were hopeful today that thunderstorms and monsoon rains might help them douse the flames but as we're about to hear, it could make their jobs harder not easier. chief environmental affairs correspondent anne thompson reports on the impact of these increasingly bigger and more destructive fires.
>> reporter: when the fires finally go out, this is when the environmental impact really begins.
>> after a fire, what's set into place is the series of events especially on steep slopes of massive erosion where the soils can literally be stripped from the land, leaving a barren wasteland.
>> reporter: transforming forever the landscape of the american west . dr. wally covington of northern arizona university says the more than 2 million acres already burned this year stripped the land of trees and soil that helped keep watersheds clean, leave hundreds of animal species without places to live and forage, and ruin the beauty that's put 25% of colorado homes in a fire risk zone.
>> what we've been seeing really not just this year but since 2000 is an increasing crescendo of heavier fires that are burning hotter than anything we've seen in historic times.
>> reporter: leaving some to question if this wildfire season is worse because of climate change. the warming of earth's atmosphere by burning fossil fuels such as oil, coal, and gas. the vast tinder box , visible from the air.
>> it makes things hotter and that of course adds to the wildfire risk but the heat dries things out more so you get more evaporati evaporation.
>> reporter: in a normal year we should have one record high temperature for every record low. so far this year there have been ten record highs for each record low and there's been much less snow and rain. boulder, colorado, home to the national center for atmospheric research , recorded its driest march to june on record.
>> when we get extreme heat and record heat, the combination of heat and dryness creates these conditions that are really explosive.
>> reporter: and consequences that are dire.
>> we won't see these forests coming back in our lifetime or even our grand children's life times.
>> reporter: altering the very environment that made america's west great. nbc news, new york.