Erlend Kvalsvik/Getty Images The world must dramatically curb greenhouse gas emissions beyond cuts agreed to in the Paris climate deal if we hope to avoid the worst effects of climate change, warns a new United Nations report.

The Paris Agreement was the most significant climate change accord in history. More than 190 countries vowed to slash greenhouse gas emissions in an effort to curb global warming.

But that commitment won’t be enough, a new United Nations report warns.

To have any chance of staving off the worst effects of climate change, the world must “urgently and dramatically increase its ambition” to cut emissions, the U.N. Environment Program said on Thursday, as it released its annual Emissions Gap Report.

World leaders need to further slash emissions by 25 percent on top of existing Paris pledges by 2030, the UNEP said. Without such action, the planet would likely see temperatures rise far higher than 2 degrees Celsius, the level scientists say the world must stay beneath to avoid the worst effects of climate change.

The report’s release is particularly notable as it comes just a day before the landmark Paris Agreement comes into effect on Friday. So far, countries representing at least 60 percent of global emissions have ratified the agreement.

“We are moving in the right direction: the Paris Agreement will slow climate change, as will the recent Kigali Amendment to reduce HFCs,” said Erik Solheim, head of UNEP, in a statement, referring to the international accord to limit planet-warming refrigerants signed in Kigali, Rwanda, last month. “They both show strong commitment, but it’s still not good enough if we are to stand a chance of avoiding serious climate change.”

Reuters U.N. Secretary General Ban Ki-moon, Chinese President Xi Jinping and U.S. President Barack Obama during a joint ratification of the Paris climate change deal in Hangzhou, China, on Sept. 3. The agreement will come into effect on Friday.

Jonathan Bachman/Reuters The National Oceanic and Atmospheric Administration said climate change made floods like those in Louisiana in August "much more likely." Scientists say limiting climate change to under 2 degrees Celcius above pre-industrial levels would reduce the impact of such events.

Associated Press Alabama is enduring its "worst drought in memory." According to NASA, megadroughts (those lasting decades) will become more commonplace in America as temperatures continue to rise.

Most of the vows in the Paris deal are voluntary and there are no repercussions for countries that fail to adhere to promised cuts. And even if all Paris pledges are fully implemented, predicted emissions in 2030 will still place the world on track for a temperature rise of 2.9 to 3.4 degrees this century, according to the UNEP.

“Emissions will be 12 to 14 gigatonnes above levels needed to limit global warming to 2 degrees Celcius,” the report said.

Scientists agree that limiting climate change to under 2 degrees will reduce the likelihood of severe weather impacts, including sea-level rise, more intense storms, longer droughts and extinction.

“If we don’t start taking additional action now, beginning with the upcoming climate meeting in Marrakesh, we will grieve over the avoidable human tragedy,” Solheim warned. “The growing numbers of climate refugees hit by hunger, poverty, illness and conflict will be a constant reminder of our failure to deliver. The science shows that we need to move much faster.”