a record-breaking heat wave continues in the southwestern u.s. today, 30 million people are under heat advisories and excessive heat warnings. this week temperatures in california's death valley rose to 128 degrees. that is six degrees shy of the hottest recorded temperature on earth ever. nbc's weather unit forecast the heat will break in the coming days, but research out this week reveals what could be behind these high temperatures. a new study shows the amount of heat the planet traps has roughly doubled since 2005. the unprecedented increase is contributing to rapidly warming oceans and air and land. researchers used satellite data to measure what is known as the earth's energy imbalance, the energy imbalance is the difference between the energy the plant absorbs and what it radiates back out. what's behind this rapid acceleration? the study points to a decrease