CNN reports:

Another wave of wildfire smoke has drifted into the US, dimming blue summer skies and igniting troubling concerns regarding the increasing frequency of fires, and what they have to do with climate change.

More than 100 million people are under air quality alerts from Wisconsin to Vermont and down to North Carolina as smoke from Canadian wildfires continues to waft south, though conditions are expected to improve slowly into the holiday weekend.

Air quality on both sides of the border has been affected as more than 500 active wildfires raging across Canada. Some fires are so out of control officials have no choice but to leave them burn.

Meanwhile, at least 10 countries have deployed their own firefighters to assist Canada with putting out the ones threatening communities whose residents have scrambled to evacuate.

Scientists continue to reiterate warnings the effects of climate change have arrived, emphasizing wildfires and the plumes of toxic smoke generated by them will become more frequent.

As plumes of smoke billow out of Canada’s forests, some may be wondering why many of the fires are being allowed to burn unchecked.

Here’s why: [Continue reading…]