“Right now, we’re facing a manmade disaster of global scale. Our greatest threat in thousands of years; climate change. If we don’t take action, the collapse of our civilisations, and the extinction of much of the natural world, is on the horizon.”

These are the powerful opening sentences chosen by Sir David Attenborough as he represented the world’s people in addressing delegates of the UN climate change summit in Poland last week.

During his speech, Attenborough encouraged the public to use the new ActNow chatbot, which has been designed to give people the power and knowledge to take action against climate change.

Recent studies show the 20 warmest years on record have been in the past 22 years, and the top four in the past four years. Scientists have advised climate action must be increased fivefold to limit warming to the 1.5C.

Over on the other side of the pond, the United States recently released its National Climate Assessment. Its conclusions reflected those of Attenborough and the UN climate summit: “the global warming of the past 50 years is primarily due to human activities, predominantly the burning of fossil fuels.”

The National Climate Assessment is a massive step forwards for American science, with more than 300 experts representing decades of work endorsed by NASA, NOAA, the Department of Defence, and over 10 federal scientific agencies.

It’s just too bad that the assessment was published in the news over the Thanksgiving holiday, when most Americans were sitting down with their families for dinner rather than reading alarming reports of climate science. Bad news buried.

The satisfaction of these scientific findings being made public was further undermined by Trump’s strategy to ignore the assessment and surge forward with plans to undo climate change policies.

Attenboroughs message is clear – humanity needs to take immediate, bold action on a global scale if we are to avoid the worst consequences of climate change, which will last for thousands of years, and in some cases (such as the extinction of plant and animal species) will be forever.