UN warns of growing gap for action as levels of greenhouse gases hit new high

There is no sign of a slowdown, let alone a decline, in greenhouse gas concentration in the atmosphere despite all the commitments under the Paris Agreement on Climate Change.

Petteri Taalas

Levels of greenhouse gases that are the main contributor to climate change hit a new high last year, the United Nations says.

The concentration of carbon dioxide in the atmosphere, which is responsible for about 80 per cent of global warming, exceeded the average annual increase of the past decade, according to a report by the UN’s World Meteorological Organisation (WMO).

The levels of both methane and nitrous oxide also hit record highs last year, the report found.

“There is no sign of a slowdown, let alone a decline, in greenhouse gas concentration in the atmosphere despite all the commitments under the Paris Agreement on Climate Change,” said Petteri Taalas, head of the WMO.

The report was released in the lead-up to next month’s climate summit in Madrid where member states will discuss ways of keeping global warming below 2C.

The 195 signatories of the 2015 Paris pact have already agreed to work towards limiting warming to 1.5C, the level the Intergovernmental Panel on Climate Change says is necessary to limit the devastating impact of droughts, floods and destruction of biodiversity.

A study from the UN Environment Programme shows that greenhouse gas emissions have also increased yet again in the past year.

Richard Black, director of the energy and climate intelligence unit, said the two reports showed “the gap between what’s needed to keep warming below 2C and what’s actu

ally happening is the largest it’s ever been”.

Global average concentrations of CO₂ reached 407.8 parts per million last year, an increase from 405.5 ppm in 2017.

There has been a 43 per cent increase in the warming impact of greenhouse gases since 1990.

Methane, which contributes to about 17 per cent of this warming, comes mostly from human activities, including cattle farming and rice growing.

Forest fires and fertiliser-use contribute to nitrous oxide emissions, which also increase warming.

The WMO study looked at the global levels of greenhouse gases which accumulate in the atmosphere, rather than emissions.

About 25 per cent of emissions are absorbed into the atmosphere, and CO stays in the ecosystem for centuries, and even longer in oceans. Levels of C0₂ are now 47 per cent higher than pre-industrial levels in 1750.

However, Taalas said that despite the US Administration’s withdrawal from the Paris agreement, “plenty of positive things are happening”.

The EU has committed to cutting its greenhouse gas emissions by 40 per cent by 2030 but Ursula von der Leyen, the Commission’s new President, is leading a push to raise that to 50 per cent. Yesterday, the EU was due to declare a symbolic “climate emergency” before the Madrid summit.

Britain this year became the first country in the G7 to legislate for netzero emissions by 2050.