Clouds changing as world warms, adding to climate uncertainty

Some clouds are rising higher into the atmosphere, where they trap more heat. Others are reflecting less sunlight, or shrinking and allowing more solar energy to reach Earth's surface. Scientists know this is affecting the climate, because the vital role that clouds play in warming and cooling the planet is well understood. Recent research has shown that clouds -- or rather, a lack of them -- helped drive a stunning surge in record-breaking global heat over the last two years. What is less certain...