Capping global warming at a 1.5 degrees Celsius rise above preindustrial temperatures by the end of the century is a human rights issue, the Philippines’ climate negotiator said Tuesday in Paris.

The call to limit warming to 1.5 C — instead of the current goal of 2 C (3.6 Fahrenheit) espoused by the United Nations — came one day after Canada joined more than 100 nations in expressing support for the more ambitious limit to be included in the Paris climate treaty.

Leaders from over 150 countries are gathering in Paris for climate negotiations aimed at drafting a global treaty to reduce national carbon emissions and plan their transition to a green economy.

“For vulnerable countries, there is a single thing that will measure the ambition of the Paris agreement, and it is a number: 1.5,” Philippine Climate Change Commissioner Emmanuel de Guzman said Tuesday in a statement from Paris.

He spoke on behalf of the Climate Vulnerable Forum, a coalition of 20 countries most vulnerable to the effects of climate change. The coalition has been pressing for a 1.5 C limit on warming to be included in the Paris agreement.

“We are the face of vulnerability. We’ve been absorbing the punches, and we will continue to receive these punches as the planet continues to warm,” de Guzman said.

Coastal communities in the Philippines have been battered by a succession of strong typhoons in recent years, as low-lying areas and islands around the world face an existential threat from rising seas. Sea level rise and extreme weather are among the effects of climate change already being seen around the globe.

Tony de Brum, the foreign minister of the Marshall Islands, an atoll nation in the Pacific Ocean that stands barely above sea level, said on Saturday in Paris that a 1.5 C limit could save his country from being submerged. “The Paris agreement must provide a pathway to survival for every country … 1.5 is much safer and is still feasible to achieve,” he said.

De Guzman on Tuesday submitted a report by the special procedures of the United Nations that confirmed a 2 C warming would have an adverse impact on human rights — “including the right to life, to health and to food, some of the most basic human rights,” he said.

Scientific evidence has shown that a 2 C warming would likely initiate feedback loops — meaning effects of climate change that lead to even more warming. One example is the melting of Arctic ice. Once the ice is gone, the surface becomes darker, which leads to more warming and the possibility of runaway climate change, according to scientists.

Low-lying nations like the Marshall Islands and coastal communities around the world would become uninhabitable at warming above 1.5 C, de Guzman and de Brum contend. Such conditions, according to the United Nations, would likely cause mass forced migrations that would dwarf the current refugee crisis in Europe.

Most of the U.N.’s human rights special rapporteurs and the Office of the High Commissioner for Human Rights have called on conference participants to include a 1.5 C limit in the Paris agreement, de Guzman said.

A draft text of the agreement published on Saturday included two possible word choices regarding the warming limit — to aim for maximum warming that was either “below 1.5 C” or “well below 2 C.”

Countries most vulnerable to climate change are not alone in calling for a 1.5 C limit. Canada, Australia, France and Germany have come out in support of including the 1.5 C goal in the climate treaty, according to the Climate Vulnerable Forum. The U.S. has hinted at support for the lower limit.

Saudi Arabia and India have been outspoken opponents of lowering the warming cap.

The world has already warmed by 1 C since preindustrial times, and the nearly 200 national pledges submitted for the Paris talks would miss both the 1.5 C and 2 C targets and put the globe on track for 2.7 C warming by 2100.

The draft text of the Paris agreement states that nations should continue to meet every five years to ratchet up the ambition of their pledges to cut emissions and switch to renewable energy. As technology and climate science advance, national pledges may be able to meet the 1.5 C target, climate experts say.

“The momentum for raising the level of ambition in Paris now opens the possibility for a truly historic and transformational summit,” de Guzman said last week, adding that he hoped “for more countries to join in the call for 1.5 C to protect human rights globally.”