UNITED NATIONS, March 28 (Xinhua) -- UN Secretary-General Antonio Guterres on Thursday called on world leaders to come to New York in September with concrete plans of action against global warming for a UN Climate Summit.

Guterres himself called for the summit scheduled for Sept. 23, a day before the start of the annual high-level week of the UN General Assembly, to crank up political will on climate change.

"It is important that we tackle climate change with much greater ambition. I am telling leaders: Don't come with a speech, come with a plan," Guterres told a news conference for the launch of an annual report of the World Meteorological Organization (WMO).

"I am calling on them to come to the summit with concrete, realistic plans to put us on a sustainable path, once and for all."

That means enhancing national contributions under the Paris Agreement by 2020 and showing how the world can reduce greenhouse gas emissions by 45 percent over the next 10 years and get to net zero emissions globally by 2050, said Guterres.

Without doing so, global warming will be irreversible, he said. "We are very close to the moment in which it will no longer be possible to come to the end of the century with only 1.5 degrees (of temperature increase above pre-industrial levels)."

The report, "WMO Statement on the State of the Global Climate 2018," states that 2018 was the fourth warmest year on record and that 2015-2018 were the four warmest years on record. Average global temperature reached about 1 degree Celsius above pre-industrial levels. 2018 also saw new records for ocean heat content and the highest global mean sea level on record, says the report.

"This report is indeed another strong wake-up call. It proves what we have been saying that climate change is moving faster than our efforts to address it," said Guterres.

He wanted the UN Climate Summit to demonstrate the benefits of climate action.

A growing number of governments, cities and businesses understand that climate solutions can strengthen economies, improve air quality and public health and protect the environment, he said. "We expect initiatives in a diversity of sectors, such as energy, sustainable agriculture, forests, oceans and resilience to climate impacts."

The summit will emphasize the importance of a just transition, where no one is left disadvantaged by necessary climate action, he said. "It is clear that a transformation is under way, but it clear that it is not as quick as needed."

New technologies are already delivering energy at a lower cost than the fossil fuel-driven economy. Solar and onshore wind are now the cheapest sources of new power in virtually all major economies, noted Guterres.

He asked for an end to subsidies for fossil fuels and high-emitting, unsustainable agriculture and for a shift toward renewable energy, electric vehicles and climate-smart practices.

He also asked for carbon pricing that reflects the true cost of emissions, from climate risk to the health hazards of air pollution.

By making this transition, the world can avert the threat of irreversible climate disruption and march far down the road to realizing the 2030 Agenda, said the UN chief.

He saw a clear link between climate change and security.

"It is clear that natural disasters ... are causing massive displacement, and this displacement will inevitably increase migration flows. And, at the same time, impacting on productivity and agriculture, it will make hunger much riskier and it will create factors of social instability."

There are interesting analyzes about the links between weather evolutions and political issues in history, he said.

"I recommend some interesting analyzes about the weather evolution before the French Revolution and some analyzes -- very interesting analyzes -- about the impacts of droughts in relation to the Arab Spring," he said. "I'm not saying that this means that there was climate change in all these circumstances. ... But it is clear that there is a link, a very clear link, between climate and security, between climate and stability, between climate and well-being of populations."