After years of warnings from scientists, global awareness of the growing threat of climate change and the need to urgently cut planet-warming greenhouse gas emissions have finally clicked into place.

Two leading climate scientists told The Straits Times that global protests by youth, record weather extremes and a series of groundbreaking scientific reports have helped drive the change.

"The planets have aligned around the climate change issue and the drive for climate change action," said Professor Jim Skea, from the Centre for Environmental Policy at Imperial College London, on the sidelines of a meeting of the United Nations' climate panel in Singapore, which ends on Friday.

The 2015 Paris Agreement, in which nearly 200 nations agreed to limit warming to well below 2 deg C and aim for 1.5 deg C, really shifted the dial, he said.

So did three special reports from the UN's Intergovernmental Panel on Climate Change (IPCC) over the past 12 months which explained the consequences of climate change on societies, as well as the solutions.

"And we've seen very high levels of social action, with the children's climate strikes. Each one has fed off the other and I think it's the combination of these factors that has led to quite a substantial change," said Prof Skea, a co-chair of the IPCC's Working Group III, which looks at ways to cut greenhouse gas emissions.

Since 1988, the IPCC has progressively warned of the growing threat from climate change, based on analysis of updated scientific findings every five to six years.

But it was the three special reports that generated perhaps the most media attention because they looked in great detail at areas vital to ordinary people.

The first report looked at the impacts of a warming of 1.5 deg C versus 2 deg C, and showed that even small increases in temperature can make a huge difference to crop production, sea-level rise and damage to coral reefs.

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The next report on land exposed how mankind's food production is wasteful, destructive and is a huge producer of greenhouse gas emissions, and how changes in diets can make a big difference.

The last report on oceans and ice-covered areas revealed the enormous threat from faster melting of ice caps and glaciers to millions of people living along coastlines and in low-lying islands.

Rapid cuts in greenhouse gas emissions from burning fossil fuels could reduce the risks.

Professor Mark Howden, an IPCC vice-chair and director of the Climate Change Institute at Australian National University, said: "The 1.5 degrees report really emphasised the urgency of the issue and how little time we have to reduce our emissions if we are to stay below 1.5.

"The land report emphasised how it was impacting on our daily lives through things like dietary choices and our health.

"But it also really emphasised there was a whole series of potential win-win solutions here. And so it wasn't just a negative message, but also a positive message."

Globally, though, the world is far from the deep cuts needed, with CO2 emissions hitting another record last year.

Global average temperatures have risen by 1.1 deg C since pre-industrial times, according to the UN's World Meteorological Organisation in a recent report.

United States President Donald Trump has said he wants to pull the US out of the Paris Agreement, while Australia wants to keep investing in coal mining to boost exports.

Prof Skea and Prof Howden said while the world was far from where it needed to be, there were positive signs.

"There's a lot more to be done," said Prof Skea. "But that doesn't mean all is lost because we have seen a lot of changes in countries already and lots of positive signs.

"The cost of renewable energy has fallen dramatically and we've seen a very rapid uptake in renewables that is probably faster than anybody had anticipated."

But he said people need the right kinds of policies to support choices that encourage greener living - for example, those that support the switch to public transport.

What is also key is a better understanding of the financial benefits of climate action.

Prof Howden said: "There's an emerging narrative that moves us away from action being a cost, to action potentially being a gain."

Pointing to switching to renewable energy or electric vehicles, he added: "We can demonstrate examples right now where choices that are made to either reduce emissions or adapt to climate change are already benefiting particular companies.

"So we need to nuance the discussion not only associated with potential costs, but also with the benefits that arise from effective action."