she worked as a flight attendant and later earned her license as a commercial airline pilot.

Melting ice has made polar bears the poster animal of climate change.Allergies and asthma are on the rise.

devastating the Great Barrier Reef in Australia.Another hit in 2010 and then from 2014 to 2017 was the biggest global mass bleaching of them all.Stunning photos of climate change 72 photos.

coordinator of the National Oceanic and Atmospheric Administrations coral reef watch.Amstrup found a 40 percent population drop since the mid-1990s.

and two-thirds of the chicks died.

mammals at risk 00:58 Nature is extremely sensitive to temperature and nature is reacting to the warmer temperatures.Her studies show that in some places in North America -- though not most -- natural weather variability could account for as much as half of local warming.

heat waves and bitter cold and snow -- has doubled in 30 years.melting about 455 billion tons of ice into water.

Human activities such as burning of coal.Marshall Ritzel/AP The biggest change over the last 30 years.