Global leaders have met in Paris for two weeks of negotiations about the new climate change deal necessary to inhibit global warming.
While the previous climate change conference in Copenhagen in 2009 ended in a fiasco, the politicians are now said to be more determined to reach an agreement as evidence is piling up about the worsening effects of rising greenhouse gas emissions.
However, multiple bones of contention are expected to come up during the negotiations.
India’s Prime Minister Narendra Modi said in an article in the Financial Times that he believed that developed countries - which built their wealth in the past on exploiting fossil fuels during a time when no one was aware of their impact on the environment - should accept more responsibility for the current situation in order to give developing countries more time to catch up.
Modi’s opinion mirrors the stance taken by China during the 2009 negotiations in Copenhagen, which eventually led to the collapse of the talks.
"The principle of common but differentiated responsibilities should be the bedrock of our collective enterprise," Modi wrote. "Anything else would be morally wrong."
India, the world’s fourth-largest greenhouse gas emitter, has pledged to cut emissions by a third by 2030, compared to 2005 levels.
During the summit, Modi is expected to announce an international solar alliance of more than 100 sunny countries, with the aim of raising India's profile on solar power.
The question of how much rich countries should invest in poor countries to help tackle climate change is also expected to be controversial, as well as the amount that should be invested in renewable energy and how much traditional oil and gas producers stand to lose if countries agree to permanently reduce emissions.
Most scientists say failure to agree on strong measures in Paris would doom the world to ever-hotter average temperatures, bringing with them deadlier storms, more frequent droughts and rising sea levels as the polar ice caps melt.
In light of the scientific evidence, the previous year has brought some signals of positive determination to resolve the stalemate from Copenhagen. In 2014, China and the US - the world’s two biggest emitters - agreed to jointly kick-start a transition towards renewable resources.
China, previously reluctant to play part in any climate change-mitigating activities, has agreed to contribute to an internationally administered Green Climate Fund that hopes to dispense $100m a year after 2020 as a way to finance the developing world's shift towards renewables.
About 150 heads of state, including US President Barack Obama and his Chinese counterpart Xi Jinping, have arrived to take part in the UN climate change talks in Paris committed to reach a strong agreement by mid-December.
On the eve of the summit, hundreds of thousands of people from Australia to Paraguay joined the biggest day of climate change activism in history, telling world leaders there was "No Planet B" in the fight against global warming.
"This past year has been a turning point," Christiana Figueres, the UN's climate chief, told delegates.
Even if a solid agreement outlining an aggressive strategy on curbing emissions is reached, the scientists have warned it wouldn’t be enough to prevent average global temperatures from rising beyond the 2°C threshold deemed safe to prevent potentially catastrophic effects on the climate system.
According to President Obama, the summit will produce a long-term framework for additional reductions down the road.
Microsoft founder Bill Gates, together with a group of private investors, has launched the Breakthrough Energy Coalition on the first day of the conference that aims to invest in early-stage energy companies developing promising renewable innovations.
The Breakthrough Energy Coalition is launching in conjunction with Mission Innovation, an international effort of more than 15 governments. Their aim is to double commitments to early-stage energy research and development, in order to discover and invent the technologies that could be developed into scalable, marketable solutions for the future, as part of a sustainable global energy mix.