LONDON: In a grim prognosis, renowned British theoretical physicist Stephen Hawking has warned that the human race today is facing the "most dangerous" time in its history.Noting that the planet is in crises, the 74-year-old Cambridge professor said the world is facing huge environmental and technological challenges and needs to unite and work together to protect the humanity."We face awesome environmental challenges : climate change, food production, overpopulation , the decimation of other species, epidemic disease, acidification of the oceans. Together, they are a reminder that we are at the most dangerous moment in the development of humanity," he said."We now have the technology to destroy the planet on which we live, but have not yet developed the ability to escape it. Perhaps in a few hundred years, we will have established human colonies amid the stars, but right now we only have one planet, and we need to work together to protect it," Hawking wrote in a recent op-ed for 'The Guardian' newspaper.Commenting on the global political shifts, Hawking attributed the rise of US President-elect Donald Trump and Britain's Brexit vote to a "cry of anger" by people who felt they had been "abandoned" by their leaders."Whatever we might think about the decision by the British electorate to reject membership of the European Union and by the American public to embrace Donald Trump as their next president, there is no doubt in the minds of commentators that this was a cry of anger by people who felt they had been abandoned by their leaders," he wrote."It was, everyone seems to agree, the moment when the forgotten spoke, finding their voices to reject the advice and guidance of experts and the elite everywhere," Hawking said.He also warned that artificial intelligence and increasing automation will decimate middle class jobs and worsen inequality, and risks creating significant political upheaval."The automation of factories has already decimated jobs in traditional manufacturing, and the rise of artificial intelligence is likely to extend this job destruction deep into the middle classes, with only the most caring, creative or supervisory roles remaining," he said.He, however, said the challenges can be overcome if the elites unite and learn from the past."We can do this, I am an enormous optimist for my species; but it will require the elites, from London to Harvard, from Cambridge to Hollywood, to learn the lessons of the past year. To learn above all a measure of humanity," Hawking said.