SINGAPORE - Carbon pollution in dozens of countries fell in the years after the signing of the 2015 Paris Climate Agreement, an analysis of emissions trends shows.

But this positive development was overshadowed by emissions growing in the majority of nations.

The study, published on Thursday (March 4) in the journal Nature Climate Change, shows that in the period from 2016 to 2019 - prior to the Covid-19 pandemic - emissions from burning fossil fuels fell in 64 countries but rose in 150. The increase in emissions was more than double the cuts achieved by the 64.

The findings are concerning because they reinforce evidence that the world is far from making the deep cuts in greenhouse gases, especially CO2, needed to shift the planet to a safer temperature path.

"We designed the study to assess progress since adopting the Paris Agreement, that is, the emphasis on the previous five years to Covid-19. It is also a key way to understand the trends that mostly will return when we get over the worst of the pandemic," said co-author Dr Pep Canadell, executive director of the Global Carbon Project, which analyses global greenhouse gas emission trends.

"We wanted to quantify that there is real progress for quite a few countries, and not only a handful of them, something that it is often overlooked and not well known," he said.

But while the progress is positive, it is a fraction of where we should be. "In fact, we are at about 10 per cent of where we should be globally," he said, referring to annual emissions cuts. Globally, CO2 emissions should be falling about 1.5 billion tonnes a year until 2050. Instead, prior to the pandemic they were still growing, albeit more slowly than the years prior to the 2015 Paris deal.

At present, humanity is well on the way to shooting past the Paris climate goals of keeping global warming to well below 2 degrees Celsius and ideally 1.5 deg C above pre-industrial levels. The United Nations says warming above 2 deg C risks triggering a climate catastrophe resulting in far more extreme and deadly weather and faster rising sea levels.

Last week, the UN's main climate body said national climate plans submitted to the world body by the end of last year showed that countries would achieve only a one per cent reduction in emissions by 2030 compared with 2010 levels - far from the 45 per cent cut scientists say is needed to limit warming to 1.5 deg C.

More concerning still, after falling seven per cent last year because of shuttered economies and travel curbs, global CO2 emissions have returned to pre-pandemic levels, the International Energy Agency (IEA) said on Tuesday (March 2).

Energy-related emissions were two per cent higher in December 2020 than in the same month a year earlier, driven by economic recovery and a lack of clean energy policies, the IEA said in a report.

Dr Canadell said that during 2016-19, emissions fell in rich nations, including Britain, the United States and Japan, but ticked upward in Australia, Canada and New Zealand.

Of the 99 upper-middle-income economies, 30 showed reductions in fossil fuel CO2 emissions. "However, a majority continued to increase their emissions, leading to this group of countries to show overall growth. Emissions from Indonesia grew by 4.7 per cent, Chile by 1.2 per cent, and China by 0.4 per cent."

These are the annual mean change for 2016-2019 compared to the annual mean of the previous five years.

What happens now is the key, he said.

It was essential for many Covid-19 recovery plans to refocus spending on green investments and away from supporting polluting industries.

Research by Vivid Economics, a consultancy based in London that did a study on government stimulus plans for 30 major economies, found that most governments had failed to use trillions of dollars in such plans to enhance nature or tackle climate change.

Their analysis, published in February, found that of the US$4.6 trillion (S$6.12 trillion) of the total US$14.9 trillion stimulus announced to date has supported environmentally relevant sectors such as agriculture, industry, waste, energy and transport, but only US$1.8 trillion has been green.

"We see a big gap, and most of all, a missed opportunity," said Dr Canadell. "It is not too often that countries engage in such large infrastructure investment efforts."

In their study, Dr Canadell and his co-authors said nations should seize on pandemic-related disruptions to drive permanent change in economies. This included incentives for electric vehicles, encourage walking and cycling in cities as well as support for public transport and regional tourism.