Many of the roughly 40 government heads who spoke at the opening of two weeks of U.N. negotiations in Madrid said policies to deal with climate change should put people's needs at their core, and address global and national inequalities too.
Bangladesh Prime Minister Sheikh Hasina said climate change had become "an existential threat for all countries", especially vulnerable countries like hers and small-island states.
"We are bearing the brunt of damage", despite having contributed very little to the greenhouse gas emissions heating up the planet, she said at an event with leaders of some particularly climate-vulnerable nations.
"This constitutes a serious injustice and must be acknowledged by the global community," added Hasina, whose country has many fragile coastal villages and refugee camps threatened by storms and rising seas.
President Hilda Heine of the low-lying Marshall Islands said by video link that, as global emissions continued to rise, "all countries need to do more" to reduce them urgently.
In her Pacific atoll nation, water covers much of the land at some point every year as tides rise higher, she said. Just last week, hundreds of people had to evacuate their homes after the capital Majuro was flooded by large waves.
"It's a fight to death for anyone not prepared to flee," she said. "As a nation we refuse to flee, but we also refuse to die."
Under the 2015 Paris Agreement, adopted by about 195 nations, governments promised to strengthen their national climate action plans every five years with the aim of keeping global warming to a lower agreed limit of 1.5 degrees Celsius.
The world has already warmed more than 1 degree since pre-industrial times, scientists say, and is expected to pass the 1.5 degree mark as early as 2030.
Nearly 70 countries - many of them island states and other developing nations - have committed to strengthen their planned emissions cuts and adaptation efforts by the end of next year.
But some of the largest emitters - including the United States, China, India and Brazil - are not among them.
"If we do not seize 2020 for that, then the next moment is 2025. We all know that waiting another half decade to do more means we lose (the) 1.5 (goal)", as temperature increases become locked in, Heine said.
"This is the same as a government deciding to pass sentence on our future - to force our country to die,” she added.
The Marshall Islands is the only country that has so far submitted an improved plan, which is aimed at meeting its goals of shifting to 100% renewable energy and cutting emissions to net-zero by 2050.
Other countries are unlikely to follow that lead until next year, but Heine said the Madrid talks should end with a decision urging all countries to raise their game by the end of 2020.
DEBT FREEZE?
On Monday, the 48 countries in the Climate Vulnerable Forum (CVF) also called for the creation of a U.N. special rapporteur on climate change and human rights, which they said they would fund with $50,000 from a new trust fund.
That fund will gather money from the vulnerable countries themselves, as well as donors such as Germany, to support cooperation among poorer countries to address climate change.
The CVF countries - from Asia to Africa and Latin America - also said they were working to provide access to $20 billion in new funds for adaptation and renewable energy over the next two years, using innovative methods.
Those methods include help for small businesses to obtain insurance, to protect their income in the face of disasters, and a mechanism to reduce the extra 10% many vulnerable countries pay to borrow money on financial markets because of the heightened climate risks they face.
Honduran President Juan Orlando Hernandez said in his country adaptation to drought and other climate extremes was crucial as coffee growers and other farmers struggle to maintain yields - and end up moving to crowded cities if they fail.
Climate-threatened countries often face paying higher interest rates when they borrow because of fears they will struggle to pay the funds back. That creates a "vicious cycle", Hernandez said.
"Developing countries pay more, making adaptation harder," he noted. He called for repayments on the debt they have accumulated to be put on hold, to free up money to invest in projects such as irrigation and forest protection.
The talks in Madrid are set to tussle over whether a new financing facility should be set up to compensate poorer countries for the "loss and damage" already being caused by more extreme weather and rising seas linked to climate change.
Richer countries have so far resisted committing to anything beyond expanding insurance for developing countries, but pressure for them to change that stance is growing as the serious impacts of a warming global climate become more evident.
U.N. Secretary-General Antonio Guterres, who mentioned witnessing storm devastation in Mozambique and the Caribbean as well as the effects of drought hitting West Africa's Sahel region, said vulnerable people were "hurt first and worst".
On Monday, he reminded governments of their promise to ensure that from 2020 at least $100 billion dollars a year is available to developing countries to help them cut emissions and adapt to climate shifts.
Governments should also take into account the legitimate expectation of vulnerable states "to have the resources necessary to build resilience and for disaster response and recovery", he added.
Harjeet Singh, global policy lead with ActionAid International, said the U.N. climate change negotiations should be about "making sure people are safe"."We need to set up a system that helps people who are already facing a climate emergency," he told media at the talks.