Warning bells have been sounded one day before the Paris Agreement come into force: If nations don't reduce predicted 2030 emissions by 25 percent, there will be no chance to limit global warming to 2 degrees Celsius (3.6 degrees Fahrenheit).

The United Nations Environment Programme (UNEP) warns in its 2016 Emissions Gap Report that by 2030, emissions are expected to reach 54 to 56 gigatonnes of carbon dioxide equivalent a year - the 2 degree limit would require maximum 42.

For reference: 1 gigatonne is roughly equivalent to the emissions generated by all transport in the European Union over a year - including aviation.

Well done, but keep working

Erik Solheim, head of UNEP, believes the world is "moving in the right direction" with the Paris Agreement and the recent Kigali Amendment to reduce HFCs.

However, he added in his statement connected to the report that "it's still not quite good enough if we are to stand a chance of avoiding serious climate change."

Commitments pledged in Paris are insufficient to fight global warming

The 2016 report points out that global greenhouse gas emissions continue to increase. This represents a major hindrance to the already challenging goal of limiting global warming to under 2 degrees this century compared to pre-industrial levels.

Emissions currently projected for 2030 would increase global temperatures 2.9 to 3.4 degrees Celsius, UNEP's analysis says.

"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 said.

Already too hot

2015 went down as the hottest year on record, and the trend continues in 2016 - the first six months have all been the warmest recorded.

This year has also been marked with headlines on growing numbers of climate refugees. Extreme weather events such as droughts and floods; breakout of disease; and poverty and conflict triggered by natural resource conflicts have been some of the reasons.

If nations do not step up action to reduce emissions, long-term objectives agreed in Paris will be impossible to reach.

For Solheim, such human tragedies "will be a constant reminder of our failure to deliver."

New actors give hope

While climate pledges agreed during the last decade - at Cancun, Paris or Kigali, among others - seem insufficient for effectively reducing global emissions, UNEP also points out some factors that bring hope.

Non-state actors - from the private sector to citizen groups - could drive a significant reduction of emissions by 2030, across sectors such as agriculture or transport, its report says.

Greater investments in energy efficiency as well represent a positive trend.

"Renewable energy and energy efficiency projects implemented in developing countries from 2005 to 2015 will reduce emissions by almost half a gigatonne by 2020," UNEP wrote, quoting a report from the 1 Gigaton Coalition.

The report is an urgent call for action - yet another. Next week's meeting in Morocco is the perfect place to start.