The new 1.5C report by the Intergovernmental Panel on Climate Change is a sophisticated intelligence briefing on the fate of our planet. Its message is relevant to every human being on Earth.

Based on more than 6,000 scientific studies, the report was compiled by more than 80 of the world’s top climate scientists from nearly 40 countries, and calibrates 40,000 peer-review comments. It is a robust and outstanding example of international cooperation, and an extraordinary source of shared intelligence.

With brutal clarity the report covers the devastating consequences of allowing global warming to reach 2C above pre-industrial levels. It makes clear that every fraction of a degree truly matters.

Quick guide What difference would restricting warming to 1.5C make? Show Hide A key finding of the new IPCC report is the dramatic difference that restricting warming to 1.5C above pre industrial levels would have on the global environment. The scientists found: • By 2100, global sea level rise would be 10cm lower with global warming of 1.5C compared with 2C. • Extreme heatwaves will be experienced by 14% of the world's population at least once every five years at 1.5C. But that figure rises to more than a third of the planet if temperatures rise to 2C • Arctic sea ice would remain during most summers if warming is kept to 1.5C. But at 2C, ice free summers are 10 times more likely, leading to greater habitat losses for polar bears, whales, seals and sea birds.

• If warming is kept to 1.5C, coral reefs will still decline by 70-90% but if temperatures rise to 2C virtually all of the world's reefs would be lost



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When compared to the impacts of a 2C temperature increase, limiting warming to 1.5C (we are already at 1C) would significantly reduce the risk of severe and extreme weather events, particularly heatwaves and heat-related mortality. It would halve the number of humans that will be exposed to water scarcity; prevent runaway sea level rise that could put many of the world’s islands under water and render uninhabitable the large delta and low-coastal regions that are home to two-thirds of the world’s population. It would prevent the almost total loss of the world’s beautiful coral reefs, protect economic growth and be far less expensive to manage.

There is nothing opaque about this new data. The illustrations of mounting impacts, the fast-approaching and irreversible tipping points are visceral visions of a future that no policymaker could wish to usher in or be responsible for.

Most striking to me, therefore, is the fact that the determinants of whether we head for 2C or for 1.5C are mainly political; they are not technical or economic.

We are already at the beginning of a global, exponential shift in the way we produce electricity – away from fossil fuels to the abundant sources of sun and wind. Since the Paris agreement was signed in 2015, the price of large-scale solar and wind energy has fallen so far it is now much cheaper in many jurisdictions than coal. Renewables are expected to outcompete fossil fuels as a new electricity source in almost every market by 2020. Electrification of transport is about to hit its exponential increase curve and cities will be transformed.

Not all sectors are seeing the same transformation yet, but the additional investment required to limit warming to 1.5C is far from overwhelming – nearly $1tn annually from now to 2050. The recent New Climate Economy report shows that those investments will not only protect us from devastating impacts, they will deliver $26tn in economic benefits by 2030 – and that is a conservative estimate. It is therefore both morally inexcusable and economically irresponsible to allow investment to continue to flow towards the further exploration of fossil fuels, rather than be intentionally directed at technologies and infrastructure that are in the solutions space.

Driven by the pursuit of clean air, new jobs, improved transport and competitive advantage, the recent Global Climate Action Summit evidenced the growing appetite of businesses, investors, cities and states to intensify their own climate action, as well as their support for national governments to send stronger signals.

Efforts to deliver positive change are inexorably marching in the right direction, but we still have an acute need for speed, radical collaboration, and more visionary political leadership.

Emissions reductions today are much more important than emissions reductions tomorrow: the sooner we bend the global curve of emissions, the more options we will have on the table for safely reaching the necessary, desirable and achievable carbon neutrality by 2050.

National governments have the evidence base and the opportunity now to set their economies quickly on that curve.

This year, nations will start the review of their original Paris commitments from 2015 as they prepare to come back to the table with increased ambition in 2020. The review process will include assessing the burgeoning suite of solutions now available to them. Many of these solutions, like the increasingly competitive price of renewables, the extraordinary technological gains in back-up energy storage, and the rapid emergence of electric vehicles, that are part of our reality now, were unthinkable just three years ago.

It is no surprise, therefore, that China, India and the EU appear to be ahead of their Paris targets, and are well placed to be frontrunners in upping their commitments in 2020. We are also seeing the formidable leadership of climate vulnerable nations such as Fiji and the Marshall Islands, who have already committed to increasing their Paris targets by 2020. Let us not forget that it was the foresight of the most vulnerable nations which introduced the 1.5C aspirational ceiling in the Paris agreement.

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Now we all have the information we need – and a better understanding of the overwhelming benefits – to move forward together to stay under that ceiling.

On climate change, ignorance is not bliss. Quite the contrary.

I encourage all policy makers to undertake a thorough review of how much has been achieved thanks to the signal they provided in Paris, and to garner the courage to provide much bolder signals now.

I encourage corporations and financial institutions to assess the risk they precipitate by not decarbonising their products, services and investment portfolios.

And I encourage all of those individuals who have the privilege and democratic right to vote, to understand the evidence presented by the IPCC today, to act in their personal lives and to vote responsibly.

We have a safer, more prosperous future to win.

• Christiana Figueres was head of the UN’s climate body for six years, including for the 2015 Paris agreement