Editor

It may already be too late for the Greenland ice sheet (Aber scientists reveal new threat to Greenland ice, Cambrian News, 8 July).

Due to climate change, the thick dome of ice which was originally two miles high, has shrunk so much that it is melting faster than ever now as it encounters warmer air at its new, lower elevation.The lower the dome gets, the cooler our climate will need to be to reverse this change.

As David Attenborough gravely says: “Unless we can significantly cool the earth’s climate, the melting of the Greenland ice cap will inevitably continue”.

Does this matter? You bet! The ice sheets of the earth have helped to keep our planet within a stable temperature range over the last 10,000 years, reflecting just the right amount of the sun’s warmth back into space for life and human civilisation to flourish.

Losing 10,000 cubic metres of ice per second on average, the melting Greenland ice cap could raise sea levels around the world by up to seven metres.

Hundreds of coastal towns and cities are now threatened - “It’s a Mad Max future that we’re facing” (Prof Jason Box, Geological Survey of Denmark and Greenland).

This is called a tipping point - beyond which change becomes irreversible. As Johan Rockström, joint director of the Potsdam Institute for Climate Impact Research, says: “One characteristic of tipping points is that once you press the On button, you cannot stop it, it takes over, it’s too late.”

Scientists have identified nine planetary boundaries that are in danger of tipping into the dangerous zone where change becomes irreversible.

As well as climate change, they include nitrogen and phosphorus flows (typically from agriculture), biodiversity loss, land use change and chemical pollution.

The film Breaking Boundaries: The Science of our Planet is both compelling and required viewing for all of us if we are to understand the existential threats that we, as a species, are imposing on the earth’s planetary systems.In the film, David Attenborough remarks that “(recent) insights are deeply troubling - nonetheless they also give us hope.”

Understanding our impacts and taking appropriate action is now essential for us all.

Dr Angie Polkey Swyddffynnon

Have your say on the local issues affecting you - email [email protected] or join in the conversation on our Facebook page