President Barack Obama finally joins Facebook with first posting on dangers of climate change

US President Barack Obama has finally joined Facebook - and used his first posting to issue a warning about climate change. Obama's warning came on the same day it was announced the average global climate for 2015 is on course to be 1C higher than the global average prior to industrialisation between 1850 and 1900.

Obama has had a Facebook page for years but this is billed as his own personal account, and in his written introduction he said he would try and balance important messages with "just-for-fun stuff". More than 20,000 people "liked" Obama's page within its first hour online. However judging by his first video message the fun stuff may have to wait.

Obama looked casual as he strolled in the back garden of his home for the past seven years, the White House. Pointing out that the garden is a national park, he said: "I want to make sure that the beauty of this particular national park, but also national parks all across the country, and our planet, are going to be there for [his daughters] Malia, Sasha, their kids, their grand-kids, for generations to come."

Only by working together, said Obama, could the problems caused by climate change be addressed. "If all of America is joining around this critical project, then we can have confidence that we're doing right by future generations and passing onto our kids all the blessings that we've received."

The problems faced not only by Americans but the whole world were starkly illustrated as the Met Office announced that 2015 could end an average 1C hotter than during the period 1850-1900 before industrialisation had an impact. That would mean it would be halfway to the 2C threshold which is seen as extremely dangerous for the future of the planet. Carbon emissions and a particularly powerful El Niño are being blamed.

Obama will attend the United Nations Conference on Climate Change (COP21) in Paris (30 November-11 December) along with UK prime minister David Cameron and other world leaders. The aim of the conference is to bring all the nations on earth together in a bid to ensure warming does not rise more than 2C above pre-industrialisation levels.