Experts at Oxford University have warned the world risks exceeding global warming of 1.5C unless countries, regions and companies set stronger climate targets.

As New York Climate Week kicks off on Monday, researchers have released several papers tracking efforts to limit warming below this critical threshold, which could lead to irreversible climate tipping points if exceeded.

The Energy & Climate Intelligence Unit (ECIU) and the University of Oxford analysed the climate targets of 198 countries, 708 states and regions, 1,186 cities, and 1,977 publicly listed companies.

In their annual Net Zero Stocktake, the researchers found that more than 40 per cent of regional and local governments still have no emissions reduction targets.

Of 708 states and regions in the Net Zero Tracker database, only 185 (26 per cent) have set net zero targets, according to the tracker.

Meanwhile, just 271 of the 1,186 cities (23 per cent) in the database have set net zero targets, most of which are in “high income” countries.

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The tracker also found that the number of company net zero targets meeting all minimum levels of integrity – meaning climate solutions are implemented in a just and credible way – remains low at 61 of 1,145.

Camilla Hyslop, Net Zero Tracker data lead from the University of Oxford, said: “The large number of entities that continue to opt out of the globally-agreed mission to curtail climate change leaves their home countries and global supply chains highly vulnerable to transition risk.

“By incentivising and supporting companies and sub-national governments to set rigorous net zero targets and plans, countries can boost the credibility of national climate goals.”

Meanwhile, the Climate Crisis Advisory Group (CCAG), an independent panel of experts from 10 nations, urged countries to widen their climate targets to include greenhouse gas atmospheric levels as a “real time” indicator of climate change.

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Its new report said long-term global temperature measurements are failing to capture the increasing rate of warming, masking the true extent of temperature rises that are having devastating impacts, especially in the developing world.

The paper also said countries need much greater ambition in the climate action plans they submit to the United Nations, known as Nationally Determined Contributions (NDCs).

Sir David King, CCAG chair, said: “We should be in no doubt that the current trajectory of global temperature increases is hurtling humanity towards disaster.

“Every nation must put everything they can towards their NDCs, to ensure the system is as ambitious and extensive as possible, while fairly addressing the needs of developing countries.”

It comes as Oxfordshire has been hit with flash flooding this week following large spells of rainfall overnight on Sunday and throughout Monday.