US President-elect Joe Biden has picked John Kerry, a former secretary of state, as his envoy on climate change in a move that underscores the importance of global warming to the new administration. Mr Biden’s transition team said Mr Kerry, 76, would break new ground by fighting “climate change full-time” as the president’s special envoy, with a seat on his National Security Council. “This marks the first time that the NSC will include an official dedicated to climate change, reflecting the president-elect’s commitment to addressing climate change as an urgent national security issue,” it said. Mr Kerry, a long-time Massachusetts senator who ran for the presidency in 2004, brokered the 2015 Paris Agreement, an international effort to limit global temperature increases to less than 1.5°C above pre-industrial levels. President Donald Trump, a Republican, pulled the US out of that deal in 2017. On Monday, Mr Kerry told his 3.4 million Twitter followers that America would soon have a “government that treats the climate crisis as the urgent national security threat it is”. “The work we began with the Paris Agreement is far from done,” he wrote. “I'm returning to government to get America back on track to address the biggest challenge of this generation and those that will follow. "The climate crisis demands nothing less than all hands on deck.” Although climate change is widely regarded as a problem at the UN and by governments around the world, the issue is divisive in the US, where many mainstream Republicans reject or downplay the threat it poses. The issue has become increasingly popular among such young progressive Democrats as New York legislator Alexandria Ocasio-Cortez, who pushed climate change up the US political agenda with her Green New Deal. Mr Biden <a href="https://www.thenationalnews.com/world/biden-s-ambitious-climate-plan-make-the-environment-relevant-again-1.1110130">campaigned on a $2 trillion plan</a> to shift to 100 per cent clean energy sources by 2050, to get the US back into the Paris Agreement and to confront climate damage. Climatologists say that floods, bushfires, hurricanes and other natural disasters are becoming more frequent and dangerous. US military reports have warned that climate change is a security threat on many fronts.