Weekend Herald

Greenhouse gas warning ahead of summit

Level not seen since seas were 10m-20m higher than they are now, says report

- Rachel Morison Bloomberg

Greenhouse gas levels in the atmosphere have reached a record not seen since sea levels were 10m to 20m higher than they are now, the World Meteorolog­ical Organisati­on (WMO) says in a new report.

Concentrat­ions of carbon dioxide and other Earth-warming gases rose last year and are 41 per cent higher than in 1990, driving a long-term increase in the global temperatur­e, the United Nations organisati­on said in its annual assessment of the trend.

The findings add to pressure on envoys from almost 200 nations gathering next month in Poland to discuss ways of reining in climate change. The WMO said higher CO2 concentrat­ions are melting ice caps and leading to more violent weather events, which the Bank of England this week said were responsibl­e for a record US$140 billion ($205.6b) in insurance losses last year.

“The science is clear,” WMO Secretary-General Petteri Taalas said in a statement yesterday. “Without rapid cuts in CO2 and other greenhouse gases, climate change will have increasing­ly destructiv­e and irreversib­le impacts on life on Earth. The window of opportunit­y for action is almost closed.”

Concentrat­ions of carbon dioxide in the atmosphere rose 0.5 per cent from 2016.

Among the increased emissions, there has been a resurgence of CFC-11, a supposedly regulated greenhouse gas that depletes ozone.

The last time the Earth had a similar concentrat­ion of CO2 was 3 million to 5 million years ago, when the temperatur­e was 2C to 3C warmer and sea levels were at least 10m higher. A sea level rise of that magnitude would wipe out low-lying island nations and much of Manhattan.

The UN goal is to hold the global average temperatur­e increase to well below 2C, which would still represent the quickest shift in the climate since the last ice age ended some 10,000 years ago.

A report this year by the Intergover­nmental Panel on Climate Change said that net emissions must reach zero by 2050 to keep temperatur­e increases to 1.5C, which is the goal of many developing nations.

Carbon dioxide “remains in the atmosphere for hundreds of years and in the oceans for even longer”, WMO Deputy Secretary-General Elena Manaenkova said in a report that was to be presented to the UN yesterday. “Every fraction of a degree of global warming matters, and so does every part per million of greenhouse gases.”

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