As pressure mounts on world's biggest emitting corporates - could the One Planet Summit yet again crown Paris as the capital for global climate action?

Even before an expected 50 world leaders arrive in Paris today, French President Emmanuel Macron's hastily arranged One Planet Summit appears be making quite a splash. In fact, the anniversary of finalisation of the Paris Agreement looks set to create even waves bigger than those from last month's fortnight-long UN climate change conference across the border in Bonn.

For if COP23 in Germany aimed to assess how the world would keep the Paris Agreement on track after this year's Trump-sized distraction, today's Summit - according to its host at least - is about reigniting the global drive for governments and businesses to accelerate the decarbonisation of the global economy.

And fresh from 54 high profile companies yesterday calling on world leaders to boost ambition on climate policy, another "unprecedented, huge and global" initiative launched this morning to coincide with the opening of the summit could end up playing a key role in pushing some of the world's biggest emitters towards more sustainable business models.

Today, as many as 225 influential global investors with more than $26.3tr in assets under management pledged to engage with 100 corporates estimated to be responsible for around 85 per cent of total global greenhouse gas emissions, so as to step up their ambition on climate action.

Dubbed Climate Action 100+, the new initiative is being coordinated by five partners: Asia Investor Group on Climate Change (AIGCC); Ceres; Investor Group on Climate Change (IGCC); Institutional Investors Group on Climate Change (IIGCC), and; Principles for Responsible Investment (PRI).

The hope is the co-ordinated effort to engage with many of the world's most carbon intensive firms could have "considerable ripple effects", according to Anne Simpson, investment director of sustainability at CalPERS - one of those investors backing the push for major companies to align their business plans with the goals of the Paris Agreement.

"Our collaborative engagements with the largest emitters will spur actions across all sectors as companies work to avoid being vulnerable to climate risk and left behind," Simpson said. "Money talks, and if we can deploy capital behind and the power of the financial markets behind the Paris agenda, we can really ensure that companies begin to make the transition that's necessary to keep global warming to a safe degree."

The collaborative initiative - which boasts a raft of high profile investors such as Allianz, AXA, BNP Paribas, Church Commissioners for England, Deutsche Asset Management, Hermes, and others as members - developed the 100-strong target list using CDP data on companies' direct and indirect emissions associated with the use of their products.

Unsurprisingly, the list is littered with huge companies in the oil and gas market such as ExxonMobil, BP, and Shell; aerospace giants including Airbus and Boeing; energy majors like E.ON, Centrica, and General Electric; automotive giants such as Volkswagen, Ford, and Volvo; and consumer goods players, including Proctor & Gamble, PepsiCo, Nestle, Panasonic, and many others.

With trillions of dollars-worth of influence behind it, the five-year initiative will make it even harder for any major listed firm to ignore or downplay the climate-related risks they face. It looks as if pressure on international climate change laggards is about to crank up several more notches two years to the day after nations signed up to the historic Paris Agreement and its goal of building a net zero emission economy this century - an ambition that has forced more and more investors to realise that carbon intensive assets now face a significant risk of being stranded by the drive to decarbonise the global economy.

Each of the 225 investors signed up so far to the new initiative have agreed to initially engage directly with at least one company on the 100-strong list. 'Engagement', they say, largely means dialogue in and around company boardrooms, including investors potentially lodging proposals at board meetings aimed at improving governance, disclosure, and action on climate change.

Specifically, investors engaging with these 100 corporates will apply boardroom pressure towards delivering three overarching goals:

The call to action may fall short of the more combative approach favoured by some divestment campaigners. But it will make it increasingly difficult for listed firms to simply dismiss calls for them to develop a business plan that is compatible with deep decarbonisation or ignore the new guidelines on climate risk disclosure.

The launch of the group also follows increasing moves at boardroom level on addressing environmental risk over the past year, with perhaps the most high profile success being the vote on ExxonMobil board earlier in the summer which mandates the oil giant to produce annual climate risk assessments, contrary to the wishes of its management.

Nevertheless, significant resistance pervades at boardroom level, according to a report last week by NGO Preventable Surprises, which suggests major investors - including names such as BlackRock, Vanguard, InvestCo and BNY Mellon, none of which have yet signed up to today's initiative - on occasions still voted against greater climate disclosure in 2016. Moreover, a separate report by ShareAction today suggests that despite some green leaders in the shape of BNP Paribas, UBS and HSBC Holdings, few European banks have yet put in place a coherent action plan to manage complex climate risks. Clearly, there is still much work to do to change attitudes at boardroom level.

But speaking during a briefing on the Climate Action 100+ initiative last week, CalPERS' Simpson said dialogue remained the most effective means of pushing for change at corporates, arguing divestment effectively "lets companies off the hook". "Engagement is not a soft option, but if we don't make sure that these companies make the transformation to a low carbon economy, we are exposed to the risk of their emissions, not just directly through the investments that we've got in those companies, but also through the indirect impact on all the other assets in our portfolio," she said. "So there's nowhere to hide from climate risk - we need to address this. We have the tools to help these companies drive this forwards."

Indeed, hiding from climate risk is becoming harder and harder. After a year that is likely to be the most expensive on record from an extreme weather disaster point of view, analysis released this week by think tank ECIU suggests scientific studies are increasingly attributing extreme weather events to climate change.

Since the conclusion of the COP21 summit in Paris on 12 December 2015, scientists have published at least 59 research papers on the attribution of specific weather events to climate change, according to ECIU. And, of these, 41 conclude that climate change has indeed increased the risks of a given type of extreme weather event, such as storms, drought, flooding and wildfire outbreaks.

Commenting on the study, Dr Friederike Otto, deputy director of the Environmental Change Institute at the University of Oxford, said vast strides in attribution science in recent years was greatly improving knowledge of climate risk to help inform policymaking.

"We're now finding that for many kinds of extreme weather event, especially heatwaves and extreme rainfall, we can be quite confident about the effect of climate change," she said. "Whether policymakers are looking at local issues such as flood protection or involved in the global climate change negotiations, the more information they have about climate change impacts now and in the future, the better decisions they're able to make. This ECIU report shows just how quickly knowledge is accumulating, and I think it's only going to accelerate."

Clearly, the scale of climate-related risk facing the 100 biggest emitting global companies has never been clearer, nor has the urgency for action to be taken. The signal today from more than $26tr-worth of investors through the new Climate Action 100+ is therefore hugely important, and makes it ever harder for climate laggards to continue turning a blind eye to what Bank of England Governor Mark Carney once described as the "tragedy on the horizon".

In that sense, Macron's One Planet Summit - convened to mark two years' since the historic COP21 conference - could yet again crown Paris as the global capital for climate action.