World leaders launched an ambitious attempt yesterday to hold back rising temperatures, with the US and China leading calls for the Paris climate summit to mark a turning point in the fight against climate change. Over 150 world leaders offered their support in a series of opening addresses. The last major summit in 2009 ended in failure, writes the BBC but French Foreign Minister Laurent Fabius, who is chairing the meeting, said a deal was within reach. Fears that dangerously high temperature rises could lead to conflict and exacerbate poverty dominated the opening day, Climate Home reports. China’s Xi Jinping warned of the “huge challenge” of the twin threats of terrorism and climate change, while US President Barack Obama called on countries to target a world “marked not by conflict, but by cooperation; and not by human suffering, but by human progress.” The host of the talks, France’s Francois Hollande, warned of water wars and increased migration, concluding: “I am not choosing between fighting terrorism and fighting global warming. These are both challenges we have to overcome”. Both the Financial Times and the Guardian live-blogged the day as it happened.

Reuters selects key comments and quotes from the leader’s speeches yesterday. Pope Francis described the world as “at the limits of suicide”, while Francois Hollande gave a similarly strong message: “Statements of intent are not enough. We are at breaking point.” Meanwhile China’s Xi Jinping gave a warning against the mentality of a zero-sum game, and expressed resolve in fulfilling Beijing’s commitments, Xinhuanet reports. Elsewhere, Associated Press compared the key leader’s speeches: Obama’s focus on ‘responsibility’; Xi’s emphasis on ‘respect’, emphasising that a deal must recognise differences between developing and established nations; Modi’s stress on ‘balance’ for a global problem “not of our making”.

More efforts to encourage low-carbon technology were announced yesterday. Indian Prime Minister Narendra Modi launched a a new body called International Solar Alliance, inviting all countries located between the tropics of Cancer and Capricorn to join, at an event co-chaired by Hollande yesterday. The ISA says it seeks to share collective ambitions to reduce the cost of finance and technology that is needed to deploy solar power widely. In a separate deal, countries and investors have pledged billions for clean energy technology Associated Press reports, in a joint initiative to bring down the cost of clean energy, that was launched yesterday by Bill Gates, Barack Obama and Francois Hollande. At least 19 governments and 28 leading world investors have signed so far, including Facebook founder Mark Zuckerberg, and Saudi Prince Alaweed bin Talal. The Guardian and the Financial Times also covered the topic.

Prince Charles is expected to call for better protection of the world’s forests at the UN climate conference in Paris, the BBC writes. He will condemn corporations which, he will argue, appear not to care if their business activities result in forest destruction.

Nicaragua has become the first country to explicitly withhold a climate plan from a UN-backed global warming pact. It refuses to join the 183 out of 195 countries in delivering an “intended nationally determined contribution”, because it says they let big polluters off the hook and collectively fail to stop catastrophic levels of warming. “We’re not going to submit because voluntary responsibility is a path to failure,” said lead envoy Paul Oquist.

A solid majority of Americans say the US should join an international climate treaty, but on this and other climate-related questions, opinion divides sharply along partisan lines, according to a new New York Times/CBS News poll. A slim majority of Republicans remain opposed. 63% of Americans said they would support domestic policy limiting carbon emissions from power plants.

It will take strenuous efforts by all to ensure that Paris is not a repeat of the Copenhagen climate summit, but “whatever happens, whatever it takes, China will, and must, be a staunch forerunner in humanity’s fight against global warming”, argues an editorial from China Daily.

What really matters is that Paris sends out a clear signal that the world is decarbonising, and there is no going back, writes Michael le Page in New Scientist. Paris is just a catalyst, he says, “we know that any agreement reached in Paris will not be enough to limit warming to the safe level of 2°C”.

A Paris treaty will “achieve very little in temperature reductions but could cost at least $1tn a year”, argues climate-sceptic author Bjorn Lomborg in the Financial Times. Spending money on climate while billions lack basic necessities, “is wrong”, he says.

An agreement is needed to prevent countries from freeriding on others’ efforts, writes Jeffrey Sachs in the Financial Times. For the first time since 1992, the US, China and the EU are aligned, now leaders must reaffirm the 2C limit in Paris, and agree to check every five years whether a tougher one is needed. They should commit to decarbonisation this century and explain by 2018 how they intend to pursue it to 2050, ignoring illogical climate-sceptic attacks on the conference.

Paris may not provide all the answers, offering at best an imperfect and non-binding deal, albeit one that includes both the US and China, according to an editorial in the Financial Times. But what it can do is to establish the framework for regular reviews on the progress as the world tries to avoid dangerous warming, and reframe action as an opportunity not a threat to wealth.

Since Copenhagen, low carbon options seem to have been taken off the shelf and genuinely put into practice. “With big corporations and even the Republican party leaping aboard the global warming train, a carbon revolution is now inevitable”, he writes.

The effectiveness of an important mosquito-fighting insecticide may be impaired by rising global temperatures, a new study suggests. In their lab, researchers exposed adult Aedes aegypti mosquitoes to the insecticide Permethrin at a range of temperatures. They found that the insecticide was less likely to be effective at killing the mosquitoes at progressively higher temperatures. These mosquitoes, which are found in the tropics and the subtropics, can transmit viruses such as dengue fever and yellow fever.

As global temperatures rise, scientists expect rainfall intensity to increase as the atmosphere can hold more moisture. But a new modelling study suggests that on the very hottest future UK days, this relationship starts to break down. The researchers find a sharp decline in the intensity of UK summer rainfall when daily average temperatures exceed about 22C. This happens because of a change in wind patterns over the UK in future, leading to hot days with less moisture in the air, the researchers say.

US individuals and organisations that produce information rejecting the scientific consensus of human-caused climate change are more likely to have their message represented in the media if they are funded by corporate benefactors, a new study says. The study analyses all written and verbal texts about climate change from 1993–2013 from every US organisation, three major news outlets, all US presidents, and every speech in US Congress. The results finds that organisations with financial ties to ExxonMobil and the Koch family foundations are better at getting their message into the news media than those without such connections.