【B1】 [br] 【B4】 [originaltext] In about 45 years, temperatures on Earth will be

In about 45 years, temperatures on Earth will be hotter than at anytime during the past one million years, says the U.S. government’s top climatologist in a new report  released today.
   According to the report, published in the  Proceedings of the National Academy of Sciences, the planet is just two degrees shy of an  average temperature of 59 degrees Fahrenheit, which is what they  believe the temperature was about a million years ago.
   NASA’s James Hansen, along with  colleagues from the University of California and Columbia University, are for the first time, marking a  calendar signaling the approach of temperatures that humans have never experienced.
   "Humans are now in control of the Earth’s climate, for better or worse," Hansen says.
    Based on a "business as usual" scenario in which greenhouse gasses continue to rise, Hansen says we’ll break the million-year-old record in about 45 years.
   What that temperature change means is that by mid-century, the world will experience even more record heat waves, wildfires, more intense storms and flooding. In other parts of the world,  the increase may worsen drought conditions as more mountain glaciers and snow packs vanish, no longer sending water to the valleys below.
   Hansen stresses we can’t wait that long to cut greenhouse gas pollution, because of the decades it takes for the climate system to respond to changes.  "We need to get started now," he says. "We can’t wait another decade or two to take this seriously."