All countries need to do more to prevent the planet overheating – but do not give in to climate change pessimism just yet

A new UN report says global emissions of greenhouse gases need to be cut by 55 per cent by 2030 to stop average temperatures rising by 1.5C

‘It is still possible to bridge the gap to ensure global warming stays well below 2C and 1.5C’ (PA)

Today’s United Nations report on the “emissions gap” is blunt in the extreme. Current commitments by the countries of the world under the Paris agreement “are inadequate to bridge the emissions gap in 2030”, it says. The gap is that between projected emissions of greenhouse gases and levels consistent with the Paris targets for 2030.

Those targets are designed to limit the warming of the planet to 2C higher than pre-industrial temperatures. The Paris agreement, signed two years ago, also set a more ambitious target of limiting the rise in average global temperature to 1.5C, to avoid some of the most serious consequences for the world’s ecosystem.

“It is still possible to bridge the gap to ensure global warming stays well below 2C and 1.5C,” the report goes on to say, but this requires much deeper cuts in emissions than are currently planned. “Global greenhouse gas emissions in 2030 need to be approximately 25 per cent and 55 per cent lower than in 2017 to put the world on a least-cost pathway to limiting global warming to 2C and 1.5C respectively.”

These are undoubtedly demanding targets, and the UN warns that the situation is worse than some optimists had started to hope. For the three years from 2013 to 2016, global emissions of the main greenhouse gas, CO2, appeared to have stabilised, prompting some experts to speculate that a turning point had been reached, after which emissions might start to decline.

The UN report confirms, however, that in the latest year for which estimates are available, 2017, CO2 emissions rose again.

Donald Trump’s decision last year to withdraw the United States from the Paris agreement added to the impression that the world is still heading in the wrong direction on climate change.

However, The Independent remains optimistic, youthful and green. President Trump’s decision will not be acted upon until at least 2019, because signatories to the Paris agreement are required to give two years’ notice of withdrawal. By then it is possible at least that Mr Trump’s presidency will be coming to an end. In the meantime, state and city governments across the US are committed to low-carbon economic policies that do not need action at federal government level.

And, although the Paris targets are hard to achieve in little more than a decade before 2030, they are undoubtedly achievable. The clarity and simplicity of the targets mean that it is becoming easier to mobilise global public opinion and the governments of large industrialised nations behind them.

The development of carbon taxes has been slower and more piecemeal than The Independent hoped in the early days of its groundbreaking reporting on environmental sustainability. However, the principles of green taxes are still the most hopeful way forward. By putting a price on the environmental damage of CO2, carbon taxes can work with the grain of market forces to minimise the economic cost of decarbonisation, while the revenues could encourage governments to pursue green priorities.

Meanwhile, the Paris agreement recognised the obligation of the richer world to help pay for the decarbonisation of poorer countries as they industrialise. Progress has been made. It has not been enough, and there have been some backward steps along the way, but we should not give in to climate pessimism yet. As the UN report says: “Now more than ever, unprecedented and urgent action is required by all nations.”