LONDON: Scientists say the world needs to cut greenhouse gas emissions by at least 45% by 2030 to have any hope of meeting Paris Agreement targets for the middle of the century and averting catastrophic warming.

Yet 41 of the world's 250 biggest corporate emitters - or 16% - are only just starting to assess their emissions, with no reduction targets set for any year, an analysis of data from research firm Signal Climate Analytics found.

And while many of the 250 companies have set targets for 2050, only 27 - or 11% - have laid out shorter-term plans to make major cuts by 2030, according to the data, compiled from corporate reports and other public disclosures.

This refers to reductions to their biggest source of emissions, often from the use of their products, or so-called Scope 3 emissions.

The 250 companies together account for more than a third of global emissions. Many campaigners say it is crucial for big polluters to set such interim targets so that authorities can gauge and drive global progress towards the Paris goals.

To try and accelerate action, the G7 group of wealthy nations this month backed moves to force companies to disclose their exposure to climate-related risks, raising pressure on them to put a plan in place to mitigate them.

"Without more incentives for 80% of the companies in these key sectors to disclose basic plans, we are unlikely to have the information necessary for markets and regulators to act constructively," said Tim Nixon, chief executive of data research firm Signal Climate Analytics.

The following graphics show the top emitters by market capitalisation in each sector and their progress on climate disclosures.