World leaders gathered Monday in New York for a United Nations summit on climate change as scientists warn much more ambitious action must be taken to meet targets to mitigate the effects, VOA reported.

Some 60 presidents and prime ministers are due to address the day-long event on topics including shifting away from coal toward renewable energy sources, preventing and responding to disasters, and climate finance.

U.S. President Donald Trump will not be among those attending the summit.  He is spending Monday attending a meeting about the persecution of religious minorities, particularly Christians, before holding separate talks with leaders from Pakistan, Poland, New Zealand, Singapore, Egypt and South Korea.

U.N. Secretary-General Antonio Guterres has sought to highlight the importance of the climate summit and challenged leaders to “come with concrete plans” and not just “beautiful speeches.”

Ahead of Monday’s event, the U.N. released a report compiled by the World Meteorological Organization showing there has been an acceleration in carbon pollution, sea-level rise, warming global temperatures, and shrinking ice sheets.

The report says the average global temperature for the period of 2015 through the end of 2019 is on pace to be the “warmest of any equivalent period on record” at 1.1 degrees above pre-industrial levels.

The 2015 Paris Climate Agreement, which has been ratified by 186 nations, calls for actions to prevent global temperatures from surpassing 2 degrees, and ideally remain within 1.5 degrees by cutting greenhouse gas emissions.  One of the world’s biggest emitters — the United States — announced under President Trump that it would leave the pact. The U.S. decision has not stopped climate action at the state, local and private sector levels.

The report warns that in order to achieve the 2 degree target, “the level of ambition needs to be tripled.”

Other global issues such as tensions between the United States and Iran; conflicts in Afghanistan, Yemen, Syria, and Kashmir; rising in equality and intolerance all figure to be themes as the U.N. General Assembly session begins Tuesday.