Major companies are increasingly concerned that they are at risk from climate change in the face of recent extreme weather events such as drought and floods, according to a report.

More than a third (37%) see the physical risks of a changing climate such as extreme weather, rising sea levels and water scarcity as a real and present danger, up from just 10% two years ago, says the latest Carbon Disclosure Project (CDP) survey of top global companies.

Four-fifths (81%) identify climate change risks to their business operations, supply chains and plans, up from 71% last year.

Of the 379 of the 500 companies who responded to the CDP's request for information about climate strategies and emissions data, 78% say they are now integrating climate change into their business strategy, up from 68% last year, the annual CDP Global 500 report said.

Businesses and economies have been hit by increasing extreme weather events in the last few years, such as widespread heatwave and drought in the US this year, fires in Russia and flooding in the UK, Japan and Thailand.

Paul Simpson, chief executive of CDP, said: "Extreme weather events are causing significant financial damage to markets. Investors therefore expect corporations to think more about climate resilience.

"There are still leaders and laggards but the economic driver for action is growing, as is the number of investors requesting emissions data. Governments seeking to build strong economies should take note."

The report suggests that the economic downturn is behind recent reductions in greenhouse gas emissions.

Reported emissions from major businesses have fallen by almost 14% since 2009 when the global economic crisis began to take hold, the equivalent of closing 227 gas-fired power stations.

Almost a third of companies report no emissions reduction at all and only two-fifths say their emissions reductions were just down to steps they had taken to tackle climate change. Other companies point to cost-cutting, such as staff redundancies, resulting in lower emissions.

In the longer term, average targets to reduce emissions among top businesses are at just 1%, compared with the 4% a year needed by countries to keep temperature rises to no more than 2C.

Professional services firm PwC, co-authors of the report which is written on behalf of 655 institutional investors with almost £50 trillion in assets, warned that businesses need regulatory certainty from governments.

Governments have not translated declarations on tackling climate change into ambitious legislation or national emissions targets, and low corporate ambition reflects that situation, the firm said.

Malcolm Preston, global lead on sustainability and climate change at PwC, said: "Even with progress year on year, the reality is the level of corporate and national ambition on emission reductions is nowhere near what is required.

"The new normal for businesses is a period of high uncertainty, subdued growth and volatile commodity prices. If regulatory certainty doesn't come soon, businesses' ability to plan and act, particularly around energy, supply chain and risk, could be anything but normal."

Guinness owner Diageo is the only UK business to make it into the CDP's top 10 companies in terms of disclosing their climate strategy and emissions and taking steps to address the issue.

Bayer and Nestle topped the table for climate change transparency and action.